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technical bulletin
MISCELLANEOUS ELECTRICAL TABLES
AND INFORMATION
ONAN 1400 73RD AVENUE N .E. • MINNEAPOLIS, MINNESOTA 55432A DIVISION OF ONAN CORPORATION
Printed in U .S .A .
JANUARY 1975
Introduction
Some of the material in this technical bulletin is in-tended to provide various electrical information forinstallations of Onan equipment, other material explainselectrical terminology, common symbols used in wiringdiagrams and schematics, etc . Characteristics ofconductors, effects of voltage drops, nominal ampereratings of AC and DC generating sets and correct wiresizes are factors to be considered for almost allinstallations .
Most of the information such as conductor characteris-tics, typical running current requirements of motors,wire sizes, has been standardized through the yearsand can be found in most electrical handbooks. Onandoes not mean to design or restrict installations throughits technical bulletins, but rather to perform as an aid .Each installation must be planned carefully, be accept-able to electrical inspectors and comply with applicablecodes and regulations .
MOTOR CIRCUIT AMPERE RATING AND INTERRUPTING CAPACITYThe ampacity (current carrying capacity) of torque motor circuits and the disconnecting means (over current protec-tion circuit breaker capacities) must be at least 115 percent of the motor nameplate capacities or a summation ofall circuit currents at the full-load condition .
To determine the equivalent horsepower for the disconnecting means to be used in a circuit, select the horsepowerrating or the next higher value from Table 3 which corresponds to the motor current for the voltage in use .
To determine the ampere and horsepower ratings for the disconnecting means to be used with combination loads,a summation of all currents (including resistance loads at the full-load condition) is used and considered as asingle motor . The full-load current equivalent is then selected from Table 3 .
The locked rotor current equivalent to the horsepower rating is selected from Table 4 . For a combined load, thelocked rotor current must be added to the ampere rating of the other loads in the circuit to obtain the equivalentlocked rotor current . For small motors not covered by Table 3, the locked rotor current should be six times thefull-load current .
For additional information, refer to the latest edition of the National Electrical Code (NFPA 70-1975) and to yourlocal electrical code requirements .
TABLE 3 . FULL-LOAD CURRENT * THREE-PHASE ALTERNATING-CURRENT MOTORS
1-
These values of full-load current are for motors running at sneers usua or e e mo orsmotors with normal torque characteristics . Motors built for especially low speeds or hightorques may require more running current, and the nameplate current rating shall be used .For 90 and 80 percent power factor, the above figures shall be multiplied by 1 .1 and 1 .25respectively .The voltages listed are rated motor voltages . The currents listed shall be permitted for systemvoltage ranges of 110 to 120, 220 to 240, 440 to 480, and 550 to 600 volts .
1
an
Induction TypeSquirrel-Cage and Wound Rotor
Amperes
Synchronous Typet Unity Power Factor
Amperes
H P 200V 230V 460V 575V 220V 440V 550V
1/2 2.3 2 1 .83/4 3.2 2.8 1 .4 1 .1
1 4.1 3.6 1.8 1.4
1-1/2 6 .0 5.2 2 .6 2.12 7 .8 6.8 3 .4 2.73 11 .0 9.6 4 .8 3.9
5 17.5 15 .2 7.6 6.17-1/2 25.3 22 11 910 32 28 14 11
15 48 42 21 1720 62 54 27 2225 78 68 34 27 54 27 22
30 92 80 40 32 65 33 2640 119 104 52 41 86 43 35
,50 150 130 65 52 108 54 44
60 177 154 77 62 128 64 5175 221 192 96 77 161 81 65100 285 248 124 99 211 106 85
125 359 312 156 125 264 132 106150 414 360 180 144 158 127200 552 480 240 192 210 168
MISCELLANEOUS ELECTRICAL TABLES AND INFORMATION
TABLE 1 . CHARACTERISTICS OF CONDUCTORS
TABLE 2. TYPICAL RUNNING CURRENT REQUIREMENTS OF MOTORS AND RECOMMENDED WIRE SIZE
A - Full rated load current in amperes (amperes while starting are much higher) .W - Minimum wire size permitted by code ; larger sizes often required - check distance for voltage drop .
2
ALLOWABLE AMPACITIES OF INSULATEDCOPPER CONDUCTORS - Based on Ambient
Temperature of 30° C (86° F) .For additional details, refer to
the National Electrical Code (NEC) Tables310-16 through 310-19 .
WIRESIZE
AREACIRCULARMILLS
OHMS PER1000 FT .
25'C or77° F .
BARECOPPERPOUNDS
PER 1000 FT .
3 Conductors orless in raceway orcable Type T, TW, of
UF .
Copper conductorin free air
Type T, of TW
4 through 6in racewayor cable
Type T, TW,of OF
14 4,109 2.575 12.43 15 20 1212 6,520 1 .61.9 19.77 20 25 1610 10,380 1 .018 31.43 30 40 248 16,510 .641 49.98 40 55 32
6 26,240 .410 79.46 55 80 444 41,740 .259 126 .4 70 105 562 66,360 .162 205.0 95 140 761 83,690 .129 258.0 110 165 88
0 105,560 .102 326 .0 125 195 10000 133,080 .0811 411 .0 145 225 116
000 167,770 .0642 518.0 165 260 1320000 211,600 .0509 640 .5 195 300 156
H . P .115V
1 PHASE AC230 V
1 PHASE AC 120 VDC 240 VDCA W A W A W A W
1/6 4 .4 14 2.2 141/4 5 .8 14 2.9 14 3.1 14 1.6 141/3 7.2 14 3.6 14 4.1 14 2.0 14
1/2 9.8 14 4.9 14 5.4 14 2 .7 143/4 13 .8 12 6.9 14 7.6 14 3 .8 141 16.0 12 8.0 14 9.5 14 4,7 14
1-1/2 20 .0 10 10.0 14 13.2 12 6.6 142 24 10 12.0 14 17.0 10 8.5 143 34 6 17.0 10 25 .0 8 12 .2 12
5 56 4 28.0 8 40.0 6 20.0 107-1/2 80 1 40.0 6 58.0 3 29.0 810 100 0 50.0 4 76 .0 2 38.0 6
ucr AzA IIAR NFr Al(1-1A7
TABLE 4. LOCKED-ROTOR CURRENT CONVERSION TABLEFOR MOTOR CIRCUITS AND CONTROLLERS
TABLE 5 . *RECOMMENDED WIRE SIZE FORA SINGLE 3-PHASE MOTOR HORSEPOWER
* - Branch circuit conductors supplying a single motor shall have an ampacity not less than 125 percent of themotor full load current rating .
3
Volts 1 .3 5 7-1/2 10 15 20 25 30 40 50 60 75
200 14 10 8 6 4 3 1 0 000 000 300 400230 14 12 10 8 6 4 3 1 0 000 000 300460 14 14 14 12 10 8 6 6 4 3 2 0575 14 14 14 14 12 10 8 6 3 2
MAX . HPRATING
Typical Motor Locked-Rotor Current AmperesSingle Phase
Two or Three Phase115V
230V
115V
200V
230V
460V
575V
1/2 58.8 29.4 24 14 12 6 4.83/4 82 .8 41.4 33 .6 19 16.8 8.4 6.6
1 96 48 42 24 21 10.8 8.4
1-1/2 120 60 60 34 30 15 122 144 72 78 45 39 19.8 15.63 204 102 - 62 54 27 24
5 336 168 - 103 90 45 367-1/2 480 240 - 152 132 66 5410 600 300 - 186 162 84 66
15 - - - 276 240 120 9620 - - - 359 312 156 12625 - - - 442 384 192 156
30 - - - 538 468 234 18640 - - - 718 624 312 24650 - - - 862 750 378 300
60 _ 1035 900 450 36075 1276 1110 558 444100 -
_1697 1476 738 588
125 - - - 2139 1860 930 744150 - - - 2484 2160 1080 864200 - - - 3312 2880 1440 1152
Volts 100
I 125 150 200 250 300 350 I
400 450 I
500
200230
600500
460 000 0000 300 500 700 900 1500 600(1) 750(1) 900(1)575 0 000 0000 250 500 600 800 1000 1500 600(1)
STANDARD VOLTAGES
SINGLE PHASE
THREE PHASE
Direct Current :For charging 6-volt battery, battery voltage 6-8 volts .For charging 12-volt battery, battery voltage 12-14 volts .For charging 24-volt battery, battery voltage 24-30volts .For charging 32-volt battery, battery voltage 32-40 volts .For charging 110-volt battery, battery voltage 110-140 volts .
For battery-less systems, generator voltage 115 .For battery-less systems, generator voltage 230 .
Alternating Current : Usually 60-hertz in U .S .A . (In foreign countries, 50-hertz current is common) .
For a more complete explanation, see technical bulletin T-005 .
120 volt, 2 wire, 1 phase
240 volt, 2 wire, 1 phase
120/240 volt, 3 wire,1 phase
240 Volt3 Wire, 3 Phase
A
CIB3 C
480 Volt, 3 wire, 3 phase . Connected as above, but higher voltage .
A
Between 0 &Between 0 &
0 Between 0 &120/208 Volt Between A &4 Wire, 3 Phase
B
C Between B &Between A &
220/380 Volt, 4 Wire, 3 Phase (usually 50 hertz) .Connected as above, except higher voltages .
4
Between A & B, 240V single-phaseBetween B & C, 240 V single-phaseBetween A & C, 240 V single-phaseAll three wires together produce240 V, 3 phase voltage .
A, 120V single-phaseB, 120V single-phaseC, 120 V single-phaseB, 208V single-phaseC, 208V single-phaseC, 208V single-phase
All three wires A, B, C togetherproduce 208 volt, 3 phase voltage .
VOLTAGE DROPA voltage drop exists in any wire carrying an electric current . It is the loss in pressure (volts) when a current(amperes) flows through a conductor which has resistance (ohms) . This voltage drop is wasted electricity as itdoes nothing productive at the other end of the conductor . It is advisable to keep the voltage drop as low aspossible to maintain the efficiency of the system . This is done by using wire of sufficient size ; the larger thewire, the less the drop . See tables 5 through 9 on wire sizes .
FIGURE 1 . EFFECTS OF VARYING VOLTAGE ON LIGHT PRODUCED BY BULB
PERCENTRATED LIGHT
110
100
90
80
70
60
poprI I 1
100 105
5
110
ACTUAL VOLTAGE APPLIED TO 115V BULB
FIGURE 2. EFFECTS OF VARYING VOLTAGE ON POWER DELIVERED BY MOTOR
115
I
A I I5 VOLT BULBBURNED AT-
I I S V PRODUCES100% LIGHT .
I I O V PRODUCES83% LIGHT105V PRODUCES70% LIGHT .
A MOTOR RATED ATI 15 V PRODUCES-
100% POWER AT 115 V(100% O F 115)
81% POWER AT 103 1/2V(90% OF I I5)
I
64% POWER AT 92V(80% OF I I5)
looPERCENTRATEDFULL LOAD 90TORQUE
80
70
60
50
4070 80 90 I00-% RATED VOLTS80'/z 92 103'/z I I5-ACTUAL VOLTS161 184 207 230 ACTUAL VOLTS
WIRE SIZESLow Voltage DC Systems : Wire sizes in Tables 6, 7, 8 apply to the largest wattage available from Onan DCbattery charging generating sets for that voltage . Distances are based on an allowable 4% voltage drop . If only a2% voltage drop is allowable, cut the distances in half . None of the amperages given for the various wire lengthsexceed the maximum amperage (ampacity) of that particular wire size . For other sizes, consult an electricalhandbook .
TABLE 6 . WIRE SIZES FOR 12-VOLT CIRCUIT WITH 4% (0 .48 VOLT) VOLTAGE DROP
* - Minimum wire size recommended is number 10 .** - One-way distance for a 2-wire run .
TABLE 7. WIRE SIZES FOR 24-VOLT CIRCUIT WITH 4% (0.96) VOLTAGE DROP
* - Minimum wire size recommended is number 12 .** - One-way distance for a 2-wire run .
6
*WIRE SIZE
12
10
8
6
4
2
1
WATTSAT 24 VOLTS
AMPERESAT 24 VOLTS
**DISTANCE IN FEET
50 2 .08 135 215 345 550 875 1390 1755100 4.17 65 105 170 270 435 690 875150 6 .25 45 70 115 180 290 460 580200 8.33 30 50 85 135 215 345 435250 10 .42 25 40 65 105 170 275 350
300 12 .50 20 35 55 90 145 230 290400 16.67 -- 27 30 65 105 170 215500 20.83 -- 20 25 50 85 135 175600 25 .00 -- -- 20 45 70 115 145800 33.33 -- -- -- 30 50 85 105
1000 41 .67 -- -- -- 25 40 65 851200 50 .00 -- -- -- 20 35 55 701400 58 .33 -- -- -- -- 30 50 601500 62 .50 -- -- -- 25 45 55
*WIRE SIZE
10
8
6
4
2
1
WATTSAT 12 VOLTS
AMPERESAT 12 VOLTS
**DISTANCE IN FEET
25 2 .08 105 170 275 435 695 87550 4 .17 50 85 135 215 345 435100 8 .33 25 40 65 105 170 215150 12.50 15 25 45 70 115 145200 16.67 -- 20 30 50 85 105
250 20 .83 -- 15 25 40 65 85300 25 .00 -- -- 20 35 55 70400 33 .33 -- -- 15 25 40 50500 41 .67 -- -- -- 20 30 40600 50.00 -- -- -- 15 25 35
TABLE 8. WIRE SIZES FOR 32-VOLT CIRCUIT WITH 4% (1 .28 VOLT) VOLTAGE DROP
* - Minimum wire size recommended is number 12 .** - One-way distance for a 2-wire run .
TABLE 9 . WIRE SIZES FOR 120VOLT DC OR AC, UNITY POWER FACTOR,2% VOLTAGE DROP (2 .4 VOLTS)
* - Above figures represent a one-way distance in feet for a 2-wire run . If a 4% voltage drop ispermissible, double the distances listed .For other voltages (120, 240, etc .), use amperes column - disregard watts . If only 1% voltagedrop is allowable, divide the distances listed by 2 .
WIRE SIZE
14
12
10
8
6
4
2
WATTS AMPERES * DISTANCE (FEET)* AT 120 VOLTS
.84 550 880 1330 2080 3400 5500 85001 .67 275 440 665 1060 1690 2750 43002 .50 183 290 450 710 1130 1850 28403 .33 137 220 330 530 840 1380 2150
500 4 .16 110 175 265 430 680 1100 1700750 6.25 73 115 177 285 450 740 1140
1000 8.33 55 83 130 214 340 550 8501500 12 .50 36 57 88 146 225 365 575
2000 16.66 27 42 68 104 166 275 4302500 20.80 22 37 52 83 135 220 3653000 25 .00 18 26 42 68 115 188 2853500 29.20 -- 23 37 63 94 155 245
4000 33.30 -- 21 31 52 83 134 2174500 37.50 -- 15 29 46 73 119 1765000 41 .80 -- -- 26 42 67 108 1666000 50 .00 -- -- 21 36 57 88 140
7000 58 .30 -- -- -- 29 46 78 1198000 66 .60 -- -- -- 26 42 67 1049000 75 .00 -- -- -- -- 36 57 93
10000 83 .30 -- -- -- -- 31 52 83
* WIRE SIZE
12
10
8
6
4
2WATTS
AT 32 VOLTSAMPERES
AT 32 VOLTS **DISTANCE IN FEET
50 1 .56 240 385 615 975 1555 2475100 3 .13 120 190 305 485 775 1230150 4 .69 80 125 200 325 515 820200 6.25 60 95 150 240 385 615250 7 .81 45 75 120 195 310 490
300 9 .38 40 60 100 160 255 410400 12 .50 30 45 75 120 190 305500 15 .63 20 35 60 95 155 245600 18.75 -- 30 50 80 125 205800 25 .00 -- 20 35 60 95 150
1000 31 .25 -- -- 30 45 75 1201200 37 .50 -- -- 25 40 60 1001400 43 .85 -- -- -- 35 55 851500 46 .88 -- -- -- 30 50 80
AC, Single Phase : For 120volt - use Table 9 ; 120/240vo1t, 3wire - use 'Table 9 for each 120-volt circuit ; 240volt - use watts column in Table 9 , multiply distances by 4 or use amperes column and multiply distances by 2 ;480-volt circuit, use watts column in Table 9 and multiply distances by 16 or use amperes column and multiplydistances by 4 .
AC, Three-Phase Systems : For a 240-volt circuit, multiply the distances in the 120-volt Table 9 by 4 for a load ofthe number of amperes indicated. Use the amperes column . For a 480-volt circuit, multiply the distances in the120-volt Table 9 by 8 for the same load . Use the amperes column .
Formula for Determining Wire Size Under Any Other Condition :
A . Direct-current and single-phase systems :
CM = D x I x 22Ed
B . Three-phase, three-wire systems :
CM = D x I x 19Ed
CM = circular mills - Wire Size (see Table 1)
I = current in amperes (In the case of three phase, it is the current in each wire .)
D = single distance on one way length of the circuit in feet .
Ed = allowable voltage drop in volts (2% of 115 volts is 2 .3 volt, etc .)
Shown below are the diameters of the various wire sizes without the insulation .
•
• 0 •
0
No. 14
No. 12
No. 10
No. 8
No. 6
No . 4
No. 2
No. 1/0
Ampacity : Current carrying capacity of electric con-ductors expressed in amperes .
Alternating Current : Alternating current (AC) is currentwhich reverses direction rapidly, flowing back and forthin the system with regularity . This reversal of currentis due to reversal of voltage which occurs at the samefrequency . In alternating current, any one wire is firstpositive, then negative, then positive and so on. Withcommercial power, the change from positive to negativeto positive occurs 60 times per second resulting in60 hertz current .
Alternator : An electric generator designed to supplyalternating current . Some types have a revolving arma-ture and in other types a revolving field .
Ampere : The ampere is the unit of measurement forelectric current . It represents the rate at which currentflows through a resistance of one ohm by a pressure ofone volt .
Capacitor or Condenser : A capacitor is an electricaldevice which causes the current to lead the voltage,opposite in effect to inductive reactance . Capacitorsare used to neutralize the objectional effect of laggingcurrent (inductive reactance) which overloads the powersource. It also acts as a low resistance path to groundfor currents of radio frequency thus effectively reducingradio disturbance .
Conductor: Substances which offer little resistance tothe flow of electric current (such as metals) . Silver,copper, and aluminum are especially good conductorsalthough no material is a perfect conductor . Each of thewires lying in the armature slots of an electric genera-tor is referred to as a conductor .
Current : The flow of electricity in a circuit (similar tothe flow of water in a pipe) . It is expressed in amperesand represents an amount of electricity, similar togallons per minute of water flow, regardless of thepressure (voltage) .
Cycle : One complete period of flow of alternatingcurrent in both directions . One cycle represents 360 °.See Frequency .
Direct Current : Current (DC) which flows in one direc-tion only . One wire is always positive, the othernegative .
Electrical Generator : An electrical generator is amachine so constructed that when its rotor is driven byan engine or other prime mover, a voltage is generated .
Exciter : An exciter is a direct-current generator whichsupplies direct current to excite or magnetize the fieldsof an alternator . An exciter may be a separate machineor be combined with the alternator .
DEFINITIONS
9
Farad : The farad is a measure of electrical capacityof condensers . A microfarad is one-millionth of a faradand is abbreviated "mfd" .
Frequency : Frequency of alternating current is thenumber of cycles per second . A 60-hertz alternatingcurrent makes 60 complete cycles of flow back andforth (120 alternations) per second . A conventionalalternator has an even number of field poles arrangedin alternate north and south polarities .
Current flows in one direction in an AC armature con-ductor while the conductor is passing a north pole andin the other direction while passing a south pole . Theconductor passes two poles during each cycle . A fre-quency of 60 hertz requires the conductor to pass120 poles per second . In a 6-pole alternator, the equiv-alent speed would be 20 revolutions per second or 1200revolutions per minute . In a 4-pole alternator, theequivalent speed would be 30 revolutions per secondor 1800 revolutions per minute .
Hertz : A unit of frequency, one cycle per second .Written as 50-hertz or 60-hertz current, etc .
Impedance : Effects placed on alternating current byinductive capacitance (current lags voltage), capacitivereactance (current leads voltage) and resistance(opposes current but doesn't lag or lead voltage) or anycombination of two . It's measured in ohms likeresistance .
Insulator : Substances which offer great resistances tothe flow of electric current such as glass, procelain,paper, cotton, enamel and paraffin are called insulatorsbecause they are practically non-conducting . However,no material is a perfect insulator .
KVA: The abbreviation of kilovolt-amperes which is theproduct of the volts times the amperes divided by 1000 .This term is used in rating alternating current machinerybecause with alternating currents, the product of thevolts times the amperes usually does not give the trueaverage power. See Reactance and Power Factor .
KVAR : The abbreviation of kilovolt-ampere reactancewhich is a measurement of reactive power that generatespower within induction equipment (motors, transformers,holding coils, lighting ballasts, etc .) .
KW : The abbreviation for kilowatt which is a unit ofmeasurement of electrical power . A kilowatt (KW) equals1000 watts and is the product of the volts times theamperes divided by 1000 when used in rating directcurrent machinery . It is also the term used to indicatetrue power in an AC circuit .
Kilowatt Hour : A kilowatt hour is the amount ofelectrical power represented by 1000 watts for a periodof 1 hour. Thus a generator which delivered 1000 wattsfor a period of l hour would have delivered l kilowatthour of electricity .
Ohm: The ohm is the unit of measurement of electricalresistance and represents the amount of resistancethat permits current to flow at the rate of one ampereunder a pressure of one volt. The resistance (in ohms)equals the pressure (in volts) divided by the current(in amperes) .
Power Factor : When the current waves in an alternating-current circuit coincide exactly in time with the voltagewaves, the product of volts times amperes gives voltamperes which is true power in watts (or in KW if divid-ed by 1000) . When the current waves, lag behind thevoltage, due to inductive reactance (or lead due tocapacitive reactance), they do not reach their respec-tive peak values at the same time . Under such condi-tions, the product of volts and amperes does not givetrue average watts. Such a product is called voltamperes or apparent watts. The factor by whichapparent watts must be multiplied to give the true wattsis known as the power factor (PF) .
Power factor depends on the amount of lag or lead, andis the percentage of apparent watts which representstrue watts . With a power factor of 80%, a fully loadedSKVA (80% PF) alternator will produce 4KW (truewatts). When the rating of a power unit is stated inKVA at 80% PF, it means that with an 80% PF load, thegenerator will generate its rated voltage providing theload does not exceed the KVA rating .
An engine-driven alternator with automatic voltageregulation, the KVA rating usually is determined bythe maximum current which can flow through the wind-ings without injurious overheating or by the ability ofthe engine or other prime mover to maintain the normaloperating speed . A resistance load such as lamp bulbs,irons, toasters and similar devices is a unity powerfactor load . Motors, transformers and 'various otherdevices cause a current wave lag which is expressedin the power factor of the load .
Reactance : Reactance is opposition to the change ofcurrent flow in an AC circuit. The rapid reversing ofalternating current tends to induce voltages that opposethe flow of current in such a manner that the currentwaves do not coincide in time with the voltage waves .The opposition of self inductance to the flow of currentis called "inductive reactance" and causes the currentto lag behind the voltage which produces it . The
10
opposition of a condenser or of capacitance to thechange of alternating current voltage causes the currentwave to lead the voltage wave . This is called "capaci-tive reactance." The unit of measurement for eitherinductive reactance or capacitive reactance is the ohm .
Resistance : Electrical resistance is opposition to theflow of electric current and may be compared to theresistance of a pipe to the flow of water . All substanceshave some resistance but the amount varies with dif-ferent substances and with the same substances underdifferent conditions .
Resistor : A resistor is a poor conductor used in acircuit to create resistance which limits the amount ofcurrent flow . It may be compared to a valve in a watersystem .
See technical bulletin T-005 on phase .
Single Phase : A single phase, alternating-current sys-tem has a single voltage in which voltage reversalsoccur at the same time and are of the same alternatingpolarity throughout the system .
Three Phase : A three phase, alternating-current systemhas three individual circuits or phase . Each phase istimed so the current alternations of the first phase is1/3 cycle (120 °) ahead of the second and 2/3 cycle(240 ° ) ahead of the third .
Voltage : Voltage is the force, pressure or electromotiveforce (EMF) which causes electric current to flow in anelectric circuit . Its unit of measurement is the volt,which represents the amount of electrical pressure thatcauses current to flow at the rate of one ampere througha resistance of one ohm . Voltage in an electric circuitmay be considered as being similar to water pressurein a pipe or water system .
Voltage Drop : The voltage drop in an electrical circuitis the difference between the voltage at the powersource and the voltage at the point at which electricityis to be used . The voltage drop or loss is created bythe resistance of the connecting conductors .
Watt : The watt is the unit of measurement of electricalpower or rate of work . 746 watts is equivalent to 1 horse-power . The watt represents the rate at which power isexpended when a pressure of one volt causes currentto flow at the rate of one ampere . In a DC circuit or inan AC circuit at unity (100%) power factor, the numberof watts equals the pressure (in volts) multiplied bythe current (in amperes) .
FACTOR
Watts
Kilowatts
Amperes
Kilovolt-amperes
(kVA)
Frequency (hertz) Hz
Revolutions per minute
Number of poles
Power factor
Horsepower (kilowatts)
Amperes when kilowatts
is known
Amperes when kilovolt-
amperes is known
Amperes when horsepower
is known
Voltage tolerance
Voltage regulation
Voltage drop
Speed regulation
ELECTRICAL FORMULAS FOR DETERMINING WATTS, KILOWATTS,AMPERES, KILOVOLT-AMPERES AND HORSEPOWER
(NEW SYMBOLS)
ALTERNATING CURRENT
A x V x PF (1-phase)A x V x 1 .73 x PF (3-phase)
A x V x PF
1000
(1-phase)
AxVx1 .73xPF
1000
(3-phase)
kW x 1000
•
x PF
AxV
1000
(1-phase)
AxVx1 .73
1000
(3-phase)
P x RPM120
Hz x 120P
Hz x 120RPM
Actual wattsAxV
A x V x PF746-W x % Eff
kW x 1000
•
x PF
kVA x 1000
V
kW x % Eff
•
x PF
•
= No-load-Full-load voltage x 100
2 x rated voltage
•
= No-load-Full-load voltage x 100
Full load volts
•
=AXc)
•
= No-load-Full-load x 100
Full load speed11
DIRECT CURRENT
AxV
AxV
1000
kW x 1000
AxV
746 x % Eff
kW x 1000
V
kW x % Eff
V
V=AxR(Q)
Watts
Kilowatts
Amperes
Kilovolt - amperes(KVA)
ELECTRICAL FORMULAS FOR DETERMINING WATTS, KILOWATTS,AMPERES, KILOVOLT-AMPERES AND HORSEPOWER
(OLD SYMBOLS)
Frequency (hertz)
Revolutions per minute
Number of poles
Power factor
Horsepower
Amperes when kilowattsis known
Amperes when kilovolt-amperes is known
Amperes when horsepoweris known
Voltage tolerance
Voltage regulation
Voltage drop
Speed regulation
ALTERNATING CURRENT
I x E x PF (single phase)I x E x 1 .73 x PF (3 phase)
I x E x PF1000(single phase)
IxEx 1 .73xPF1000
(3 phase)
KW x 1000E x PF
I x E (single phase)1000I x E x 1 .73
1000
(3 phase)
P x RPM120
F x 120P
F x 120RPM
Actual wattsIxE
I x E x PF746 x % Eff
KW x 1000E x PF
KVA x 1000E
HPx746x%Effh x PF
% _ No-load - Full-load voltagex 1002 x rated voltage
No-load - Full-load voltage% =
Full load volts
x 100
E=IxR
% _ No-load - Full-loadx 100
Full load speed
12
DIRECT CURRENT
IxE
IxE1000
KW x 1000E
IxE746 x % Eff
KW x 1000E
HP x 746 x % EffE
E=IxR
OHM'S LAW: Ohm's law states that the current in an electric circuit is equal to the pressure dividedby the resistance .
The equations may be written :
OHM 'S LAW :
A = V
Amperes = VoltsS2
Ohms
•
= A D Volts = Amperes x Ohms
•
= V Ohms = VoltsA
Amperes
A graphic symbol represents the function of a part inthe circuit . They are used on schematic diagrams andwiring diagrams . They are correlated with parts lists,descriptions and instructions .
A schematic diagram shows, by means of graphic sym-bols, the electrical connections and functions of aspecific circuit arrangement . It aids tracing the circuitand its functions without regard to the actual physicalsize, shape or location of the component device orparts .
A wiring diagram is used for wiring and tracing out theconnection in the circuit . The placement of parts orassemblies shall usually show the general physicalarrangement of the control . It may cover internal orexternal connections or both .
NOTE : See nominal ampere ratings of AC and DC units at theend of this bulletin.
ELECTRICAL SYMBOLS
13
OLD
FACTOR
NEW
•
. . . . . . . . . . voltsVFfrequencyHz•
. . . . . . . . . .wattsWHPhorsepowerkWIamperesARresistance (ohms)0Zimpedance (ohms)AC 0KWkilowattskWKVAkilovolt ampereskVA•
. . . . . . . . . . number of polesPPFpower factorPFRPMrevolutions per minute . . . RPM%Effpercent efficiency%Eff
The standard symbol for a terminal ( 0) may be addedto each point of attachment to the connecting lines toany one of the symbols .
The polarity symbol, + for positive, - for negative, isused as necessary and if clarity is required to under-stand a circuit function .
The ground symbol - is a direct conducting connec-tion to the earth or body of water or a conducting con-nection to a structure that serves as an earth ground(such as the frame of an air, space, or land vehicle) .
For simplification of a schematic diagram, parts of asymbol for a device such as a relay, or contactor maybe separated . If this is done, suitable designationsare used to show proper relationship of the parts .
A
ASSEMBLY, SUBASSEMBLYIt is an assembly of items that is mounted and prewiredas a unit, which can not be identified in a specific groupor which may contain items made up of other parts .
AR
AMPLIFIER
MOTOR1. General (fan, blower)
2. Series Field
B
3 . Application : Engine Starting Motor
SER FLD
BTBATTERY
The long line is always positive, polarity must beidentified in addition (shown as multicell) .
CCAPACITOR
If it is necessary to identify the capacitor electrodes,the curved element shall represent the outside electrodein fixed paper-dielectric and ceramic dielectric capaci-tors, and the low potential element in feed throughcapacitor .
1 . General
LIST OF SYMBOLS
14
2. Polarized, Electrolytic Capacitor
CIRCUIT BREAKER1 . General
3. Feed-through Capacitor (with terminals shown on feed-through element for clarity .)
Commonly used for bypassing highfrequency current to chassis.
CO- 0
TCB
2. Circuit Breaker with thermal overload device .
3. Circuit Breaker with magnetic overload
4. Circuit Breaker with thermal magnetic overload device .
old drawings)
I
device .
5 . Application : 3-pole circuit breaker with thermal mag-
netic overload device in each pole and trip coil (shown
with boundary lines)
CRRECTIFIER, DIODETriangle points in direction in which rectifier conducts cur-rent easily .1 . l Diode, Metallic Rectifier, Electrolytic Rectifier, Asym-
metrical Varisitor .
SCR
2. Application : Full-Wave Bridge Type Rectifier .
5. Zener Diode
3. Controlled Rectifier (SCR)
CR
4. Bidirectional Diode (Suppressor)
1 5
6. Tunnel Diode
CR
01
CT
CURRENT TRANSFORMER1. General
2 . Current Transformer with polarity marking .
Instantaneous direction of current into one polarity markcorresponds to current out of the other polarity mark .
CT
DSSIGNALING DEVICE except meter or thermometer.
1 . Audible Signaling device .1 .1 bell
DS
1.2 . buzzer
1 .3 . howler
-8-
DS
F~2 . Visual Signaling Device (indicating, pilot, signal or
illuminating lamp)
2 .1. incandescant lamp
DS
II
DS
2 .2. neon lamp
2.2 .1 alternating-current type
2. Permanent magnet
4.1 .2. magnetic
4 .1 .3 . thermal magnetic
DS
2 .2 .2 . direct-current typeNOTE: Polarity mark is not part of the symbol .
DS
EELECTRICAL SHIELDING, PERMANENT MAGNET, SPARKPLUG, MISCELLANEOUS ELECTRICAL PARTS .1 . Electrical shield (short dashes) normally used for ele-
tric or magnetic shielding. When used for other shielding,a note should so indicate .
16
4.2. fuel pump
4.3 sending units (oil, water, etc .)
©A
FFUSE
GENERATORS1 . General
G
( old drawings
∎•'
F
Indicates slip ringsor collector rings .)
E 2. Field,
2 .1 .
Generator
compensating or commutatingIPM1
3 . Spark plug
E2.2 series
--
4 . Miscellaneous Electrical part 2 .3 . shunt or separately excited .4.1. engine choke
4 .1 .1 . thermal
E 3 . Winding Symbols
3 .1 . 1-Phase
3 .2. 3-Phase wye
3 .3 3-Phase delta
4. Application: charger generator and cranker .
GSER FLD
SHUNT FLD
5. Application: revolving armature generator (shown assingle phase, 3 wire)
7. Application : Magneto
6 . Application: revolving field generator (shown as 3-phasewye, 4 wire
FLD
2a -
H
HARDWARE (bolts, nuts, screws, etc .) if applicable .
HRHEATER, manifold, glow plug, general .
HR
RECEPTACLE-fixed or stationary connector .The connector symbol is not an arrow head . It is largerand the lines are drawn at a 900 angle .
1. Female Contact
11
2. Male contact
3 . Application: 4-conductor connector with 3-male contactsand 1-female contact with individual contact designa-tions .
orif no confusion results from its use by disregarding thetype of contacts in the receptacle, it may be shown as
J
B
C
4. Receptacles of the type commonly used for power-supplypurposes (convenience outlets)
4.1 . female contact
r__1
4 .2. male contact
5. Application : 3-conductor'polarized connector with femalecontacts.
6. Application : 3-conductor polarized connectorcontacts .
4-4-
with male
KRELAY, CONTACTOR, SOLENOID (electrically or thermally
operated)1. Coil1 .1 . basic operating
1 .2 . time delay
2. Contacts2.1. basic contact assemblies2.1 .1 . closed contact (break)
K~
KC OR - -
2.1 .2 . open contact (make)
K0K OR ---
t2.1 .3 transfer
K
O L OR -t
~~
2.2 . contacts with time delay feature.2 .2 .1 . closed contact, time delay opening
KI
KOff- OR ---K-
TDO
TDO
2.2 .2 . open contact, time delay closing
K
K0-- OR - i H-
TDC t
TDC
2 .2 .3 closed contact, time delay closing
K
KOL OR -j+ -
TDC
TDC
Note : contacts at left are for wiring diagrams . Contacts atright for schematic diagrams & wiring diagrams ofcontactors .
18
2 .2 .4 open contact, time delay opening
K
K0- OR -H F-
TDO t
TDO
3. Application: Relay with transfer contacts
INDUCTOR, REACTOR1. Air core
L
2. Iron Core (if desired to distinguish magnetic-core in-ductors)
L
3 . Saturating core
K
K
L
4 . Saturable-core inductor (reactor)NOTE: explanatory words & arrow are not part of the symbolshown
DC WINDING
M
METERS, GAUGES, CLOCKS with calibrated dials1. clock, electric timer1 .1. motor
dH
1 .2 . transfer contacts
M
C--z-
2 . Indicating meters, gauges, etc .
*replace the asterisk by one of the following letter com-binations, depending on the function of the meter .
A
AmmeterAH
Ampere-hourF
Frequency meterMA
MilliammeterOP
Oil PressurePF
Power FactorT
TemperatureTT
Total Time (Running Time)V
VoltmeterW
WattmeterWH
Watthour meter
MP
MECHANICAL PARTS including nameplates - if applicable
PPLUG. affixed to a cable, cord or wire
The connector symbol is not an arrowhead . It is largerand the lines are drawn at a 90 0 angle .
1. Female contact
2 . Male contact
3. Application : 4-conductor connector with 3-male contactsand 1-female contactwith individual contact designations .
OR -
19
orif no confusion results from its use by disregarding thetype of contacts in the plug, it may be shown as
P
BC
4. Plugs of the type commonly used for power-supply pur-poses (mating connectors)
4 .1. female contact
4.2. male contact
5 . Application: 3-conductor polarized connector with femalecontacts .
6 . Application : 3-conductor polarized connector with malecontacts
TRANSISTOR1. General1 .1 . NPN
1 .2 . PNP
-A-
2 . Unijunction2.1 . N-type base
2 .2. P-type base
3. Field-effect3.1 . N-type base
3 .2 . P-type base
Q
Q
R
RESISTORdo not use both styles of symbols on the same diagram
1 . General (fixed)
R-AA/A- OR -H R I--
2 . Tapped
R-v /V` OR -JR F-
3. Adjustable contact
R
_r OR -4R~ f-
4 . Rotary type adjustableThe preferred method of terminal indentification is todesignate with the letters "CAA" the terminal adjacent to
20
the movable contact when it is in an extreme clockwiseposition as viewed from the knob end .
Rheostat
5. Non linear
ROR
OR IWA
RTTHERMISTOR; THERMAL RESISTOR
"T" indicates that the primary characteristic of the ele-ment within the circle is a function of temperature
RT
VARISTOR, SYMMETRICALresistor, voltage sensitive (silicon carbide, etc)
RV
-ti~'_VOR 127/
S
SWITCH1. Thermal cutout, thermal flasher
OR
2 . Switch2.1 . momentary-fixed contact on momentary switch
2 .1 .1 . open contact (make) (ignition points)
2 .1 .2 . closed contact (break)
So-
-%'-RV
2 .1 .3 . 2-open contacts (make)
SO- OFF
2.1 .4 . push button, open contact (make)
!LLA A-
2 .1 .5 . push button, closed contact (break)
2 .2 .3 . 2-open contact (make)
2.2. locking or maintained-fixed contact for maintained switch .
0
2 .2.1 open contact (make)
S0~o
2.2 .2. closed contact (break)
2.3. application : 3-position, 1-pole; circuit closing (make),off, momentary circuit closing (make) .
S0
OtAOFF
2 .4. application : 2-position, 1-pole ; momentary circuit clos-ing (make), circuit closing .
2 1
2.5, selector switch2.5 .1 . 4-position with non-shorting contacts
S
000 OR
2 .5 .2 . 4-position with shorting contacts
S
S000 OR
2.6, master or control switchA table of contact operation must be shown on the dia-gram. A typical table is shown below .
DETACHED CONTACTS SHOWNELSEWHERE ON DIAGRAM
X indicates contact closed
•
2 1 0• 4 30• 6 5 0•
8 70
FOR WIRING DIAGRAM
2.7 . flow actuated switch2.7 .1 . closing on increase in flow
S
O-e
0
O
0
0
CONTACT POSITIONA B C
1-2 X3-4 X5-6 X7-8 X
2 .7 .2 . opening on increase in f low
S0--6
2.8. liquid level actuated switch2.8 .1 closing on rising level
2 .8.2 open on rising level
°b°2.9 . temperature actuated switch
(thermostat)2 .9 .1 . closing on rising temperature
2 .9 .2 opening on rising temperature
S
0-72 .10. pressure or vacuum actuated switch2 .10 .1 . closing on rising pressure
2.10 .2 opening on rising pressure
O-r
22
2.11. centrifugal actuated switch (overspeed)2.11 .1 . closing on speed
2 .11 .2 . opening on speed
TTR&NSFORMER-ignition coil1 . Iron core
2. Air core
TB
THERMOCOUPLE
TB
TERMINAL BLOCK-MARKER STRIP
TB TBOR 0TC
TC
VRVOLTAGE REGULATOR, CHARGE, CURRENT
WCONDUCTORS, CABLE, WIRING,BUSBAR, ETC.
1 . Conductive path or conductor; wire
2. Two conductors or conductive paths
3 . Three conductors or conductive paths
4. Crossing of paths or conductors not connected . The cros-
sing is not necessarily at a 900 angle .
5 . Splice
6. Junction of connected paths, conductors, or wires (otherthan a terminal)
7 . Terminal
may be added to each point of attachment to the connectinglines to any one of the graphic symbols .
0
8 . Shielded single conductor
r'1V
9 . Shielded 2-conductor cable with shield grounded
23
10. 2-conductor cable
11. Grouping of leadsNormally, bend of line indicates direction of conductor
joining cable
JJJJI
1-1
OR
JJJJJ12. Associated or future (short dashes)
XFUSEHOLDER, SOCKET, LAMPHOLDER
ZNETWORK, General
Where specific letters do not fit, when considered a part .
10 0 0 01 31 32 33 34
STAT I CEXCITER
GENERATOR WINDING DIAGRAM
SINGLE PHASE (SHOWN AS CODE 3)Mi
M2
M33 PHASE WYE (UNGROUNDED) Mi
M2
M33 PHASE WYE (GROUNDED)
(SHOWN AS CODE 4)Mi
M2
M3
MO
revolving field generators (AC Output)
AFi AFZ0 0 0
Ei E2I
TYPICAL SYMBOL APPLICATIONS
ZI
-JJ Wo LL.
W
RECONNECTION BLOCK 120/240V . 1-Phase, 4-Wire
24
GENERATOR WINDING DIAGRAM
i-PHASE TI
T2
T3
3-PHASE WYE
3 PHASE DELTA
itT2T3TO
TiTOT273
TIiTiT7721 T2T8T31T3T9T4T5T6
TOTIOTIITit
12 lead reconnectable shown connected for120/208 V, 3 PH, 4 W . leadwire order may
be changed according to specific output .LOAD CONNECTIONS
MiM I 120 v T'MiM 2 120 V M2 ~ 240 V M2 240 V.
M3 12O v. M3 lw~M3M4M4M4
K
Relay with D.P .D .T . contacts
Time delay relay with S .P .D.T. contact
Relay with time delay feature by means of thermalelement with S .P .S .T. contact (manual reset)
K
TYPICAL SYMBOL APPLICATIONS
Relay with time delay feature by means of motor with SPDT contacts .
25
TYPICAL SYMBOL APPLICATIONS
4-position cam operated 13-circuit switch (voltmeter and ammeter selector switch No . 308B22) .
--10 f -0 I XI
Ii 0-i I
xr X INDICATESICLOSED CONTACTS 1
26
SCHEMATICDIAGRAM
8
WIRINGDIAGRAM
POSITIONS
_IOFF`1
2 3
01 02 03 ~'I~'i H-O X I04 I
I3
I
II
~'10605
07 08 09I
I
l
i
~W
I
I
I. 61 0A 08 OC I
I
I
I
I
iOp •
• xI ~
8IOE OF 0G I •
x X I II
IA1OH J 1 0 D 1 I X
1
C
I C I0-i I
i I I l
ELECTRICAL SYMBOLS AS SHOWN ON OLD STYLE DRAWINGS
CROSSOVERUsed to designate where two wires cross but are notelectrically connected . Any one of the symbols maybe used .
CONNECTED CROSSUsed to designate where two wires cross and are elec-trically connected . A dot is shown at the point of con-nection .
TAPUsed to designate where one wire is electrically con-nected to another wire . A dot is placed at the pointof connection .
TGROUNDUsed to indicate that the circuit is completed throughthe generator frame or engine . Connections which arenot insulated from the frame are called grounded con-nections . Used also when it is desired to use the earthas a return circuit .
SWITCHUsed to indicate a simple switch .
2 1
CIRCUIT BREAKERUsed to designate an automatic safety switch . Theamperage at which it opens automatically is usuallyprinted near the symbol .
RELAYUsed to designate a relay, where the current of oneelectrical circuit is used to control one or more otherelectrical circuits .
STOP BUTTONUsed to show the stop button of the power plant . Noticethat one terminal is grounded .
STO P
STOP-START BUTTONSUsed to show the start and stop buttons mounted to-gether on the power plant or remote station . One terminalof each button is grounded to a common ground con-nection .
STOP
START
J ICJ L
POSITIVE SIGNUsed to designate the positive post of a battery, thepositive brush of a generator or the positive side of thecircuit in general .
NEGATIVE SIGNUsed to designate the negative post of a battery, thenegative brush of a generator or the negative side ofthe circuit in general .
BATTERYUsed to designate either a storage or dry cell battery .
-1-1 1 1 1 1 -
RHEOSTATUsed to designate a rheostat . The resistance of a rheo-stat can readily be varied by means of a knob or lever .
COILUsed to designate a coil of wire such as the fieldcircuit of a generator or a relay coil .
MMINDUCTION COILUsed to designate an induction coil having a primarywinding (P) and a secondary winding (S) . It usually hasa soft iron core . This symbol is used for showing theignition coil in the magneto and battery ignition sys-tems .
,IRQLQ.QIQL SP
TRANSFORMERUsed to designate a transformer for changing the voltageor current in an alternating current system .
28
CONDENSERTwo ways used to designate a condenser . The one onthe right generally is used .
TRECTIFIERUsed to designate a rectifier for changing the currentin an alternating current system to direct current .
AMMETERUsed to designate the ammeter in a circuit . An ammeteris used to measure the current flow in the circuit .
kcl
Ammeter with Shunt, used only on DC circuits carryinghigh amperages . Only a very small portion of the currentpasses through the meter .
SHUNT
Ammeter with Current Transformer, used only in ACcircuits carrying high amperages . Only a small portionof the current flows through the ammeter and secondarycircuit .
Ammeter in Circuit, series connection . Notice the directreading ammeter is connected in the circuit to measure
the amperes .
Ammeter in Circuit, with shunt . Notice the shunt is con-nected in the circuit . The shunt is connected in serieswith the battery and resistor, and the ammeter is con-nected parallel with the shunt . Only used in DC circuits .
uAmmeter in Circuit, with transformer . Notice the primarywinding of the current transformer is connected in thecircuit. Only a small amount of induced current passesthrough the secondary winding and the ammeter . Usedon AC circuits only .
0
(~vVOLTMETERUsed to designate a voltmeter. A voltmeter measuresthe pressure in the circuit .
Voltmeter in Circuit, parallel connection . The voltmeteris always connected across the circuit to measure thevoltage .
29
COMMUTATOR AND BRUSHESUsed to designate the commutator and brushes on DCgenerators and motors .
SLIP RINGS OR COLLECTOR RINGS AND BRUSHESDesignates slip rings and brushes on AC generator .Alternating current is collected from them in the revolv-ing armature type generator. Direct current is passedthrough them into the field coils of the rotating fieldtype generator .
∎
E03NORTHUsed to designate the north pole of a permanent magnetor electromagnet .
NSOUTHDesignates the south pole of a permanent magnetelectromagnet .
SFIELD POLESUsed to designate the field poles of a generator . Thepoles may be either electromagnets or permanent mag-nets .
∎
or
SPARK PLUG
RESISTORTwo ways used to designate spark plugs . The essential
Designates a resistor . Usually the resistance in ohmsfeature consists of a break (or gap) in the wire and then
will be given near it .a connection to ground .
ISP
J
CONTACT POINTSTwo methods used to designate contact points of dis-tributors, magnetos or relays .
30
VARIABLE RESISTORDesignates a resistor arranged so
effective resis-tance can be varied .
N AA
O N
O O
WO
WO
OW O OW
WO
ONNNf
.O O 0
t0 J
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0 0J O 0
F-'F-'
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JO
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0 0
V IT
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0 0
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0 0
In A
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0 0AW
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0 0W O 0
N VI O
N O O
- J N
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X
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NOMINAL AMPERE RATINGS - DC GENERATORS
32
DIRECT CURRENT CODE AND VOLTAGE BATTERY CHARGING CODE AND VOLTAGE
CODE 115
123
150 212 224 232 210
Nominal_Volts __
_12-15-VAMP
28 .2-24-30-VAMP
37 6-32-40-VAMP
29 25-VOLTAGE
KW115-V
230-V
250-VAMP
AMP
AMP
.4
.5
.6.75
1 .01 .251 .52 .02 .53 .03 .55 .06 .0
10 .015 .0
3 .5
1 .74
1 .64 .4
2 .2
2 .05 .2
2 .6
2 .46 5
3 .2
3 .08 .7
4.010 .9
5.013 .0
6 .017 .4
8 .021 .8
10.026 .0
12 .030 .4
14.043 .5
20.052 .2
24.087 .0
40.0130 .0
60.0
28 .435 .442 .553 .271 .088 .6106 .4142 .0
177 .3213 .0248 .0355.0
14.217 .721 .326 .635 .544.353 .271 .088.6
10 .613 .315 .9519 .926 .633 .340 .053 .266 .580 .093 .0133 .0
116 .0
Onan manufactures a complete line of electric power systems from I to 500 KW (generatorsets • automatic transfer switches* industrial engines), gas-, gasoline- or diesel-driven. For standby power in homes, industrial plants, commercial buildings andinstitutions . For auxiliary or portable power in boats, recreational vehicles, servicetrucks and construction equipment.
PARED
P`
IONAN
'CATIONI?
P_
technical bulletin
INSTALLATION OF ELECTRIC GENERATING SETS
FOR
RECREATIONAL VEHICLES
ONAN 1400 73RD AVENUE N .E . • MINNEAPOLIS, MINNESOTA 55432A DIVISION OF ONAN CORPORATION
Printed n U .S .A . OCTOBER 1976
WARNING,
SAFETY PRECAUTIONSThe following symbols in this manual signal poten-tially dangerous conditions to the operator or equip-ment . Read this manual carefully . Know when theseconditions can exist . Then, take necessary steps toprotect personnel as well as equipment .
Onan uses this symbolthroughout this manual to
warn of possible serious personal injury .
This symbol refers to possibleequipment damage .
Fuels, electrical equipment, batteries, exhaust gasesand moving parts present potential hazards that couldresult in serious, personal injury. Take care in follow-ing these recommended procedures .
•
Use Extreme Caution Near Gasoline . A constantpotential explosive or fire hazard exists .
Do not fill fuel tank near unit with engine running .Do not smoke or use open flame near the unit orthe fuel tank .
Be sure all fuel supplies have a positive shutoffvalve .
Fuel lines must be of steel piping, adequatelysecured and free of leaks . Use a flexible section offuel line between generator set and stationary fuelline in the vehicle . This flexible section must be100% NON-METALLIC to prevent electricalcurrent from using it as a conductor .
Have a fire extinguisher nearby . Be sure ex-tinguisher is properly maintained and be familiarwith its proper use. Extinguishers rated ABC bythe NFPA are appropriate for all applications .Consult the local fire department for the correcttype of extinguisher for various applications .
•
Guard Against Electric Shock
Remove electric power before removing protec-tive shields or touching electrical equipment . Userubber insulative mats placed on dry wood plat-forms over floors that are metal or concrete whenaround electrical equipment . Do not wear dampclothing (particularly wet shoes) or allow skinsurfaces to be damp when handling electricalequipment .
Jewelry is a good conductor of electricity andshould be removed when working on electricalequipment .
Always use an appropriately sized, approveddouble-throw transfer switch with any standbygenerator set. DO NOT PLUG PORTABLE ORSTANDBY SETS DIRECTLY INTO A HOUSERECEPTACLE TO PROVIDE EMERGENCYPOWER . It is possible for current to flow fromgenerator into the utility line . This creates ex-treme hazards to anyone working on lines torestore power .
Use extreme caution when working on electricalcomponents. High voltages cause injuryordeath .
Follow all state and local electrical codes . Have allelectrical installations performed by a qualifiedlicensed electrician .
•
Do Not Smoke While Servicing Batteries
Lead acid batteries emit a highly explosivehydrogen gas that can be ignited by electricalarcing or by smoking .
•
Exhaust Gases Are Toxic
Provide an adequate exhaust system to properlyexpel discharged gases. Check exhaust systemregularly for leaks . Ensure that exhaust manifoldsare secure and not warped .
Be sure the unit is well ventilated .
•
Keep The Unit And Surrounding Area Clean
Remove all oil deposits. Remove all unnecessarygrease and oil from the unit . Accumulated greaseand oil can cause overheating and subsequentengine damage and may present a potential firehazard .
Do NOT store anything in the generator compart-ment such as oil cans, oily rags, chains, woodenblocks etc. A fire could result or the generator setoperation may be adversely affected . Keep thefloor clean and dry .
•
Protect Against Moving Parts
Avoid moving parts of the unit . Loose jackets,shirts or sleeves should not be permitted becauseof the danger of becoming caught in movingparts .
Make sure all nuts and bolts are secure . Keeppower shields and guards in position .
If adjustments must be made while the unit isrunning, use extreme caution around hotmanifolds, moving parts, etc .
Do not work on this equipment when mentally orphysically fatigued .
Table of ContentsGENERAL 2Model Selection 2Considering Load Applications 2Air Conditioning Loads 2
LOCATION 4Compartment Location 4Compartment 5Mounting 5Vibration Isolators 5
VENTILATION AND ACOUSTICS 7Vacu-Flo Cooling 7Air Requirements 7Suggestions for Quieter Operation 7
FUEL SYSTEM 10Fuel Consumption 10Fuel Lines and Fuel Filters 10Fuel Solenoid 11Gasoline Evaporative Control Systems 11
EXHAUST SYSTEM 13Exhaust Spark Arresters 13
ELECTRICAL LOADS AND CONNECTIONS 14Wire Types 14Disconnect Switch 14Recommended Transfer Mechanisms 14Load Connections 14Starting Controls 16Final Check-Out Procedure 16
BATTERIES 18Battery Care 18Batteries and Battery Cables 18Battery Cables 18Battery Selection 18Battery Size 18
REMOTE ACCESSORIES 19PRE-START CHECKS 21
WARNING
TO PREVENT FIRE OR ACCIDENT HAZARD . . .THIS UNIT MUST BE INSTALLED ACCORDINGTO THE MANUFACTURER'S DETAILED IN-STALLATION PROCEDURES OBSERVING ALLMINIMUM CLEARANCES .
TO AVOID POSSIBLE PERSONAL INJURY OREQUIPMENT DAMAGE, ANY INSTALLATIONAND ALL SERVICE MUST BE PERFORMED BYQUALIFIED PERSONNEL .
1
The requirements and recommendations throughoutthe bulletin are based on the :
1 . National Electrical Code (NEC) .
2. Recreational Vehicle Institute, Inc .(ANSI A119 .2) .
3. National Fire Protection Association(NFPA 501C) .
4. Recommendations of Onan engineers,distributors, dealers and servicemen .
5. CSA Requirements (Bulletin #946) .
All requirements and recommendations are used inconjunction with manufacturers of motor homes,display vehicles, trailers and associated RV equip-ment. State and local codes must also be followed .
Due to various recreational vehicle chassis types anddifferent installations, information given is quitegeneral and must be adapted for particular in-stallations. Refer to the appropriate operator'smanual and/or installation guide for specific informa-tion .
MODEL SELECTIONSize, weight, electrical characteristics, etc., are im-portant when determining the correct Onangenerator set for a given recreational vehicle applica-tion . However, read the entire bulletin coveringcooling, fuel and wiring before making a final choice ifthe unit is expected to :
1 . Deliver rated output when installed in compart-ment .
2. Start dependably .
3. Operate safely .
4. Be serviceable .
General
TABLE 1. ELECTRIC GENERATING SETS
Can be two-wire connected for rated output at 120 volts or three-wire connected for 120/240 volts .Higher ampere rating shown is for 120 volts .
2
CONSIDERING LOAD APPLICATIONSWhen determining the size of the generator setthought to be needed for a given electrical load,consider the following points :
1 . Total appliance loads to be used . . . refrigerator,water heater, water pump, etc . Note starting loadssince they place higher demands than runningloads. See Table 2 .Consider air conditioning loads separately sincethey are often the largest load in the recreationalvehicle (see Air Conditioning Loads) .
2. Loads which operate simultaneously .
3. Extra loads which might be added in the future .
AIR CONDITIONING LOADSProbably the largest single load encountered for theelectric generating set in a recreational vehicle in-stallation is an air conditioner . Generator set sizing,more often than not, is dependent on the nature andcharacteristics of the air conditioner . Most air con-ditioners used are designed to operate from a com-mercial power source and can present problems toelectric generating set . For this reason, care must betaken in selecting the set for air conditioning loads .
Current draw from any air conditioner is high whilestarting and becomes less as the air conditioner'smotor reaches synchronizing speed . The instant theair conditioner's compressor starts pumpingrefrigerant, the load on the motor and current drawincreases again . After the inside temperature of therecreational vehicle lowers, motor load and motorcurrent draw declines . The air conditioner operates
t
ELECTRICAL CHARACTERISTICS
MODEL WATTS I VOLTS
I AMP
I PHASE WIRE WEIGHT (LB)
2 .5LK-3CR 2,500 120/240 20.8-10.4 1 4* 225
2.7AJ-1 R 2,750 120 22.9 1 2 147
4.OCCK-3CR 4,000 120/240 33.4-16.7 1 4* 290
4.OBF-3CR 4,000 120/240 33.4-16.7 1 4* 2174.OBF-1 R 4,000 120 33.4 1 2 3005.OCCK-3CR 5,000 120/240 41 .6-20 .8 1 4* 3156.0NH-1 R 6,000 120 50.0 1 2 382
6.5NH-3CR 6,500 120/240 54.2-27 .1 1 4* 327
TABLE 2.POWER REQUIREMENTS FOR APPLIANCES
Appliance or ApproximateTool Running Wattage
Refrigerator 600-1000Electric broom 200-500Coffee percolator550-700Electric frying pan1000-1350Hair dryer 350-500Electric stove (per element)350-1000Electric iron 500-1200Radio 50-200Electric water heater1000-1500Space heater 1000-1500Electric blanket 50-200Television 200-600Electric drill 250-750Battery chargerUp to 800Electric water pump500-600Air Conditioner1400-2200Converter 300-350Microwave Oven700-1500
for some time and probably stops . Restarting the airconditioner, probably the largest single starting testfor the generator set, is more difficult because theinternal temperature of the air conditioner hasbecome much higher . With these points in mind, usethe set selection procedure following .
TABLE 4. ELECTRIC GENERATING SET STARTING CAPACITIES (100O F Ambient)AND AVAILABLE ACCESSORY LOADS*
` - Available accessory loads based on typical values for recreational vehicle air conditionersfrom Table 3 and set capacities .Add 500 watts to available accessory load after vehicle interior cools to 80°F .Simultaneous starting .
3
1 . Determine the running watts of each air con-ditioner from the nameplate . For operation in100O F ambients, add 300 watts to the runningwatts. See Table 3 .
2. Select the electric generating set from Table 4 . Itgives the available accessory load in watts of eachset while starting various air conditioners inambients up through 100° F .
Available accessory load will vary from installation to installa-tion . Factors affecting this amount are altitude, carbon andlead buildup in engine, ambient temperature, compartmentcooling system design, type of air conditioner and its startingtime. Some can be compensated for by derating to assure theset and air conditioner operate properly . See steps 3 and 4 .
3. Derate the generator set 4 .5 percent foreach 1000feet above 1000-feet altitude (9 percent at 3000-feet altitude, for example) .
4. Carbon and lead deposits in the set enginerequire a 10 percent derating if not removed aftereach 500 hours of operation .
TABLE 3.TYPICAL AIR CONDITIONER LOADS
SeriesAvailable Accessory Load (Watts)While Starting One Air Conditioner
Available Accessory Load (Watts)While Starting Two Air Conditioners**
11,000BTU
12,000BTU
13,500BTU
11,000BTU
12,000BTU
13,500BTU
2.5LK 1300 1000 800 I I2.7AJ 1500 1200 10004.0BF-3CR 2500 2300 2000 Not Recommended4.OBF-1 RPower Drawer 2500 2300 2000
4.000K-3CR 2500 2300 20005.000K-3CR 3800 3500 3300 2000 1800 16006.ONH-1 RPower Drawer 4600 4400 4100 3200 2600 2200
6.5NH-3CR 5000 4800 4400 3800 2800 2500
BTUAIR CONDITIONER
ONE AIRCONDITIONER'SLOAD (WATTS)
11,000 180012,000 200013,500 2200
COMPARTMENT LOCATIONCompartment location is determined largely by :1 . Physical size .2 . Access opening .3. Mounting support . . most important of all .
Physical SizeThe area in the vehicle for the electric generating setmust be large enough for the compartment withminimum clearance between the generator set andcompartment walls or ceiling (and acousticalmaterial, if used) as specified by Onan in eachindividual installation guide .
Access OpeningPlan the location for an access opening large enoughto permit set removal. Compartment door should be
Location
FIGURE 1 . TYPICAL ELECTRIC SET INSTALLATION
4
designed for easy removal, orso door can be proppedup for operator's or serviceman's ease .
Mounting SupportBecause of compartment weight, the most desirablemounting location is between the main framemembers of the recreational vehicle . However, this isseldom possible. Most common installations are onthe side of the vehicle and most difficult to reinforce .One side of the compartment is fastened to the frameand the opposite side secured to the body (Figure 1) .Channel, box or angle iron can be used for acompartment frame with a sheet metal cover .
The compartment can be supported from above whenthe unit is below the level of the recreational vehiclemain frame members . However, compartment struc-tural design must be rugged enough to withstandsevere forces in all directions .
COMPARTMENT1 . Compartment or installation area must be
separated from living quarters by a vapor-tightwall .
2. Line the compartment or separate generator setfrom living quarters with a fire barrier of sheetmetal or other noncombustible material . Thecompartment can also be readily sealed and lendsitself easily to sound or acoustical treatment .
WARNING Do not use flammable material directlyabove or around the generator set com-
partment. Heat transferred through the sheet metal compart-ment structure or other material can be high enough todiscolor, char or ignite fiberboard, seat cushions, etc . Use ofasbestos or other noncombustible temperature insulatingmaterial in high temperature areas may be necessary .
3 . Clearance between compartment walls or ceiling(and acoustical material, if used) and set shouldbe adequate to prevent the temperature of com-bustible material from exceeding 1170 F (65 0 C)rise. For models with generator cooling inlets onthe generator end, make sure adequate clearance(one inch minimum) is left for entrance of coolingair. Refer to individual installation guides for ULlisted models .
4. Compartment bottom must have minimalopenings to reduce entrance of road dirt .• A sheet metal base plate is desirable. However,
plywood of sufficient thickness for strengthcan be used if covered with sheet metal forprotection .
•
Equip base with a drain hole to outside ofcompartment .
Be sure hole is not directly abovemuffler to prevent fire hazard .
•
Do not use absorbent material on inside ofcompartment floor.
5 . Locate the battery outside generator set compart-ment. See the section on Batteries.
MOUNTINGBefore actual mounting of the generator set takesplace, read the entire bulletin . Also, consider thefollowing mounting points:
1 . Air cleaner should be easy to remove .
2. Battery or batteries must be accessible .
3. Oil fill, drain and oil dipstick should be easy toreach and service .
WA RNING I
FIGURE 2 . TYPICAL "POWER DRAWER" MODEL
4. Sufficient clearance must be left around exhaustsystem See EXHAUST section .
Though not usually the case due to installationrestrictions, Onan RV sets of 6500 watts and less canhave a compartment with the unit on a pull-out tray forservice and repair . Load wires, control wires and fuellines must have sufficient slack and flexibility so unitcan slide out without disconnecting them . The 4.0BFand 6.ONH Power Drawer models are self-containedgenerator sets mounted on a pull-out drawer asstandard . Their fuel and electrical connections are onthe outside of the compartment. See Figure 2 .
If the unit has a mounting plate, bolt the unit and platesecurely in place . If the unit does not have a plate, seeVibration Isolators .
VIBRATION ISOLATORSRubber vibration isolators are furnished with all Onanrecreational vehicle models .
Use only the vibration isolators provided withthe electric generating set, as they are design-
ed to support unit's weight .
1 . Onan mounts are a "fail safe" type which preventthe unit from breaking loose if they are damaged .
2 . Vibration isolators of the type shown on the lowerright (with snubbing washers) in Figure 3 must beinstalled properly to minimize vibration . Leave1/16-inch minimum clearance between the snub-bing washers as shown .
LK FOCALIZED MOUNT
899
AJ FOCALIZED MOUNT
RUBBER CONE MOUNTFOR CCK CCKB . NH AND BF
FIGURE 3. VIBRATION ISOLATORS
6
Ventilation and Acoustics
The most important factors of ventilation for an air-cooled RV electric generating set are sufficientincoming cooling air and exhausting heated air .Before considering the installation problems,knowledge of how an Onan unit cools itself is needed .
VACU-FLO COOLINGAll Onan electric generating sets for recreationalvehicles use Vacu-Flo cooling, a centrifugal fan in ascroll housing on the engine end (Figure 4) .
1 . It draws air from the generator end of thecompartment, through the generator and over thecooling surfaces of the engine, then dischargesthe heated air out through the Vacu-Flo dischargeopening .
2. All standard sets for recreational vehicles havethe Vacu-Flo scroll positioned downward . Be surenothing obstructs or restricts discharged airflow .
WARNING Never use discharged cooling air for heatingsince it can contain poisonous gases .
Allow for ducts or obstructions of airflow . Position ofthe air openings must permit airflow while the unit isrunning to purge the compartment of heated air . Buton shutdown, the openings must allow for convectioncooling of the compartment for heated air to escape .
AIR REQUIREMENTSCooling air requirements for ' Onan electricgenerating sets vary with type and size . While figures
FIGURE 4 . TYPICAL ONAN RV COOLING SYSTEM
1
TABLE 5. RV ELECTRIC SET AIR REQUIREMENTS*
- BF and NH "Power Drawer" models have fixed air inlet and outlet .NOTE: Allow for airflow restrictions due to elbows in a duct, etc .
for air discharge are given in Table 5, special equip-ment is needed to measure it. Since the dischargearea can't be changed, air inlet opening is critical .Table 5 also gives the total free inlet area recommend-ed .
Restricted Air OpeningsExpanded metal, screen or sheet metal with louvers orslots can be used over inlet areas . However, someprovide only 60 percent free inlet area per square foot .Even the most efficient grille only provides about 90percent free inlet area per square foot . The free inletarea of the material can be obtained from themanufacturer. Calculate the inlet area needed usingthe following example as a guide .
Example: Unrestricted air inlet requirements for agenerator set is 140 square inches. The compartmentdoor louvers provide 85 percent free inlet area persquare foot. Divide 140 square inches by 0.85 (85percent) to determine necessary inlet area .
140 sq. i n .
0.85= 165 sq. i n .
Air Inlet LocationIf possible, always locate the air inlet on the side of thevehicle and as high as possible to minimize entranceof dirt and dust. With a rear air inlet, the generator setoften has difficulty moving sufficient cooling airthrough the compartment, due to the vacuum createdbehind the vehicle during transit .
SUGGESTIONS FOR QUIETEROPERATIONTwo general types of noise encountered with agenerator set for recreational vehicles are airborneand structural vibration noise. Most structural vibra-tion noises can be reduced by vibration isolators, skindampers in the form of lead-filled plastic or other
RV SERIES RPM
AIRDISCHARGE(CU.FT./MIN.)
MIN . FREEAIR INLET, NORESTRICTION
(SO. IN.)
MIN . AIROUTLET SIZE
(SCROLL OPENING)
2 .5LK 1800 450 100 (3 x 8)2 .7AJ 3600 325 75 (4'/ x 7)4 .000K 1800 550 100 (3 x 8)4 .0131` 1800 480 85 (91/2 x 3'/)5.000K 1800 550 100 (3 x 8)6.5NH 1800 650 120 (4 x 8)
high-density attachable materials, flexible fuel andelectrical connections, etc. Compartment acousticallining and special compartment design can usuallyreduce airborne noises .
Compartment Acoustical Lining1 . Be sure all joints and corners of the compartment
are vapor tight to coach interior before lining withacoustical material .
Lining the compartment does little if opening, cracks, doorand joints are not sealed . Also make sure compartment dooredge is sealed to eliminate noise-air leaks around the doorperimeter.
2. Cover the sound reflective surfaces, back, top andsides (not compartment base) with fiberglass orother noncombustible acoustical material . Itshould be no less than one-inch thick and ap-proximately four pounds per square foot indensity. Be sure adhesive used is also noncom-bustible. Test acoustical material and adhesivefor heat effects before using .
3. Rather than using fiberglass or like material offour pounds per square foot density, a combina-tion of materials can reduce noise even more . Forexample, a sheet of lead of visoelastic material ofone-half to one pound per square foot density anda layer of one-inch acoustical material of fourpounds per square foot density, respectively, isfar more superior .
4. To prevent line of sight noise indication, a soundpanel (baffle) may be added behind lowered airinlet. The panel must be spaced to allow forminimum free air inlet of 100 square inches . SeeFigure 5 .
Separate installation area or compartmentfrom living quarters by a vapor-tight wall to
prevent entrance of noxious fumes to interior .
WARNING 1
FIGURE 5. BAFFLE CONCEPT COMPARTMENT
8
Compartment DesignCompartments can be designed to prevent line-of-sight noise radiation . Four types of compartmentdesigns are discussed :
1 . Baffle concept .2. Shelf concept .3. Panel concept.4. Z-duct concept .
The baffle concept is accomplished by mounting apanel on the inside of a louvered service door (Figure5). The panel must be spaced to allow for free inletairflow, yet not allow line-of-sight to the generatorset. Often this compartment does not lend itself toeffective noise reduction because the louvers in thedoor extend beyond the panel's edges .
Shelf-concept compartments are effective becausethey allow more acoustical material to be used on theair inlet . The incoming air goes pastthe unit and mustmake one 90-degree turn before entering the com-partment proper (Figure 6). Available space above orbeside the generator set determines the depth of theshelf. Depth of the shelf must not restrict airflow .
However, due to space limitations, the shelf-conceptis seldom possible . For such instances the panelconcept can be used (Figure 7) . It requires very littleroom and prevents line-of-sight to the noise source .
One of the most effective compartment designs is theZ-duct concept . Incoming air must make at least one90-degree turn (usually two) before it enters thecompartment . See Figure 8 . Depth of the duct must bedetermined to allow for inlet air and still allow forclearance between the generator set and the back
LOUVERED OR SCREENEDAGAINST RAIN
'
~' cg
SHELF
FIGURE 6. SHELF-CONCEPT COMPARTMENT
FIGURE 7 . PANEL-CONCEPT COMPARTMENT
side of the duct and acoustical material, whereapplicable . Acoustical material lining inside the duct,if used, must not restrict airflow .
Air Outlet DuctNoise of discharged air from the compartment can be
9
FIGURE 8 . Z-DUCT CONCEPT COMPARTMENT
reduced by adding a duct (Figures 5 through 8) todirect the airflow under the vehicle . For most effectiveacoustical treatment, line the duct with acousticalmaterial which is resistant to oil or gas absorption,and is fire resistant. Ducting or acoustical treatmentmaterial must not restrict discharge airflow from theset .
All Onan AC electric generating sets for recreationalvehicles use gasoline fuel. Because any AC generatorset runs at a constant speed, lead deposits tend tobuild up in the combustion chambers . Forthis reason,use clean, fresh, no lead or low-lead gasoline. Regulargrade gasoline may also be used, but DO NOT usehighly leaded premium types of fuel .
For new engines, the most satisfactory results areobtained by using nonleaded gasoline . For olderengines that have previously used leaded gasoline,the cylinder heads must be taken off and all leaddeposits removed from engine before switching tononleaded gasoline .
Lead deposits must be removed from anengine before switching from leaded to non-
leaded gasoline. If not, preignition can occur causing enginedamage.
Most Onan recreational vehicle gasoline generatorsets have electric fuel pumps as standard . The otherrecreational vehicle models have mechanical fuelpumps. Choice of fuel pump type used is primarily forprevention of vapor lock .
WARNING Leakage of gasoline in or around the com-partment is a definite hazard . The ventilation
system should provide a constant flow of air to expel anyaccumulation of fuel vapor while the vehicle is in transit . Com-partments must be vapor tight to the interior to keep fumes fromwithin the vehicle.
Gaseous FuelThis fuel does have some advantages over gasoline,but Onan does not use (on AC RV models) and doesnot recommend gaseous fuel operation forthefollow-ing reasons :
1 . Complex installation-requires special lines,solenoid valve, strainer, regulators, gauges, etc .
2. High installation costs .3. Usually limited bulk fuel availability .4. Set capacity limited by physical size of tanks .5. Lower engine power.6. Poor and erratic low temperature starting and
operation .
FUEL CONSUMPTIONIt should be noted that under varying electrical loads,engines for recreational vehicle generator sets canuse up to the fuel consumption figures shown in Table6 for rated output .
Fuel System
10
TABLE 6. FUEL CONSUMPTION
If the vehicle fuel tank is shared, design the fuel tankwithdrawal system to insure the set cannot use theentire supply. See Sharing Fuel Tank Supplyfollowing .
SHARING FUEL TANK SUPPLYMost electric generating set installations are design-ed to share the vehicle fuel supply tank with thevehicle engine . All connections to vehicle fuel systemmust be in accordance with chassis (vehicle)manufacturers' detailed installation instructions .
FUEL LINES AND FUEL FILTERSFuel Lines
1 . Use seamless steel tubing and flared connec-tions .
2. Run fuel lines at the top level of tank to a point asclose to the engine as possible to reduce dangerof fuel siphoning out of tank if the line shouldbreak .
3. Keep fuel lines away from hot engine or exhaustareas . This reduces chance of vapor lock .
4 . Line must be long enough to prevent binding orstretching because of set movement .
5 . Install an approved flexible nonmetallic and non-organic fuel line between the solid fuel line andengine to absorb vibration .
6. Install lines so they are accessible and protectedfrom damage .
7. Use nonferrous metal straps without sharp edgesto secure the fuel lines .
Fuel FiltersOnan electric generating sets with electric fuel pumpshave phenolic or screen filters within the fuel pumpitself . Additional filters in the fuel line are un-necessary unless unusual operating conditions exist .
MOBILEUNIT
GALLONS/HOUR(at rated load)
2.5LK 0.522.7AJ 0.544.000K 0.884.013F-3CR 0.884.013F-1 R 0 .885.000K 1 .056.ONH 1 .056.5NH 1 .30
Operating the generator set from a tee in the main fuel line cancause erratic operation. The set's fuel pump has neither thecapacity nor the power to overcome the draw of vehicle engine fuelpump .
FUEL SOLENOIDThe positive fuel shutoff valve prevents flooding of thegenerator set, when not in use, should the vehicle fueltank become pressurized .
GASOLINE EVAPORATIVE CONTROLSYSTEMSWith the increasing emphasis on pollution controls,certain states are now requiring strict evaporativecontrols on vehicle gasoline supply systems .Manufacturers of RV chassis and vehicles in generalhave complied to new regulations for these areas byusing special design gas tanks, filler tubes, filler gascaps and interconnecting vapor tubing from thevehicle gas tank through a special canister to thevehicle engine.
Because these systems are designed to operate in acritical pressure range, it is very important duringconnection of an electric generating set and buildingof the motor home, etc., the vehicle manufacturer'sfuel supply design not be altered . The filler tube, filllimiter vent, canister, vapor lines and gas fill capshould not be changed, removed or replaced unlessreceiving recommendations and approval from thevehicle manufacturer. If not, serious vehicle engineand generator set operating conditions could result .Always check the filler gas cap to make sure it has apressure and vacuum relief valve . Also check to makesure it works .
Because various designs of such systems exist,Figure 9 shows a typical gasoline evaporative controlsystem. By checking the vehicle chassis for acanister, vapor lines, etc., you should be able toidentify whether or not it has an evaporative controlsystem .
If operating problems develop due to the fuel system, check the fillcap to make sure the vacuum and pressure relief valve Is workingproperly .
1 1
FIGURE 9. TYPICAL EVAPORATIVE CONTROL SYSTEM
WARNING'
12
ENGINE EXHAUST GAS (CARBON MONOXIDE) IS DEADLY!
Carbon monoxide is an odorless, colorless gas formed by Incompletecombustion of hydrocarbon fuels . Carbon monoxide is a dangerous gas thatcan cause unconsciousness and is potentially lethal . Some of the symptoms orsigns of carbon monoxide Inhalation are :
•
Dizziness • Vomiting•
Intense Headache • Muscular Twitching•
Weakness and Sleepiness • Throbbing in Temples
If you experience any of the above symptoms, get out into fresh airimmediately .
The best protection against carbon monoxide Inhalation is a regular inspectionof the complete exhaust system . If you notice a change in the sound orappearance of exhaust system, shut the unit down Immediately and have itinspected and repaired at once by a competent mechanic .
Plan each individual exhaust system carefully . Agoodinstallation not only is gas tight, but usually quieter,too . Be sure to check all applicable recreationalvehicle standards, local codes and regulations .
WAR NING IDo not connect the generator set exhaust tothe vehicle exhaust system . Water vapor from
one engine can damage the other engine .
1 . Where the exhaust system passes through thebase or floor, leave adequate clearance as protec-tion against exhaust pipe damage from vibration(Figure 10) .
2. The exhaust system must be no closer than sixinches from any combustible material ; or, be solocated, insulated or shielded so it does not raisethe temperature of any combustible material bymore than 117 F degrees above the ambient airinlet temperature after the generator set has runat full load for one hour .
3. The exhaust system must terminate aft of thegenerator set compartment and extend to theperimeter of vehicle .WARNING 11 Do not terminate exhaust under vehicle, as
~~ carbon monoxide gas is poisonous . Directexhaust gases away from window and door openings .4. Exhaust pipe must terminate a minimum of three
feet from the vehicle gasoline filler spout (moredistance if required by local codes) .
5. Use the largest possible radius elbows on theexhaust lines and as few elbows as possible . Ifnot, the system might create high back pressure .
6. Use automotive type tail pipe hangers forhangingthe exhaust system from vehicle undercarriage .
If tail pipe deflector is used, be sure it islarge enough to prevent excessive back
pressure .
EXHAUST SPARK ARRESTERSExhaust spark arresters are necessary whenoperating in some parks and camps . Two basic typesare used in the recreation vehicle industry . One is a
IMPORTANT: Certain states (particularly California) have stateordinances pertaining to the type and usage of exhaustmuffler/spark arresters on internal combustion engines or enginedriven equipment when used in a recreational vehicle such aselectric generating sets . Be sure your installation meets all Federal,State and local codes pertaining to your unit. Failure to provide andmaintain a spark arrester may be in violation of the law .
Plan the exhaust system carefully. Exhaustgases are deadly!
Exhaust System
1 3
WARNING I
FIGURE 10. TYPICAL EXHAUST SYSTEM INSTALLATION
spin-out type spark arrester, the other is a screen typespark arrester . All require periodic clean-out (every50 to 100 operating hours) to maintain maximumefficiency .
Spin-Out Type Spark ArresterThis type removes carbon particles by centrifugalforce, catching the particles in a holding chamber .Removing a pipe plug from the arrester and operatingthe generator set (at a convenient time and place)cleans out the deposits . It is important to note thisarrester does not plug up when the holding chamberis full and does not cause harmful, high exhaust backpressure. When full, particles pass through thearrester .
Screen Type Spark ArresterThis arrester has a screen which traps carbon par-ticles as they pass through . The screen is removed,cleaned or replaced after it has filled . A disadvantageof this type is the screen plugs as it collects theparticles and gradually increases exhaust backpressure. Back pressure causes a loss of enginepower and can cause burned or damaged valves ifpressure is high enough. It is very important this typebe cleaned as recommended .
On all listed models with exhaust shieldingsupplied with unit, shielding MUST be
properly installed to prevent overheating of compartment walls orthe possibility of fire . Refer to appropriate installation guide foreach model for details .
All of the following description pertains to alternatingcurrent On an electric generating sets for recreationalvehicles .
1 . All wiring must meet applicable local electricalcodes. Have a qualified electrician install andinspect the wiring .
2. Wires must be adequate size, properly insulatedand supported in an approved manner .
3 . Mount switches and controls securely to preventdamage from vibration and road shocks . Allswitches must be vibration-proof to prevent ac-cidental opening or closing while the vehicle is inmotion .
4. Install an approved junction box for feeder con-ductors from the electric generating set. It musthave a blank cover and be inside compartment(not on set) .
To prevent noxious gases from entering vehi-cle interior, seal any openings made in the
set's compartment for conduit, wiring, etc .
WIRE TYPESUse multistrand wire which meets all applicablecodes as feeder conductors, from electric generatingset to compartment junction box . Many installers usemultistrand wire throughout the vehicle to reducethedanger of breakage from vibration .
The generator set conductors must be able to carry atleast 115 percent of the generator nameplate current(amperes). Neutral conductors must be the same sizeas the conductors of the outside legs .
Supply conductors from the electric generating set tothe junction box on the compartment wall must beinstalled in flexible conduit .
Do not use solid metal conductors in com-partment . They may develop metal fatigue
from set movement and eventually break .
Because of fire hazard, do not tie electricalwiring to fuel line.
DISCONNECT SWITCHThe feeder conductors from the set compartmentmust terminate in a double-pole, double-throwpositive off switch device for 120 volt operation beforethe vehicle distribution panel . This assures the out-side power source cannot be connectedsimultaneously with the electric generating set . For
WAR NING 1
Electrical Loads and Connections
WARNIN1
14
120/240 volt operation, a 3-pole, double-throw,positive off, switching device must be used . Neutralmust be switched .
RECOMMENDED TRANSFERMECHANISMSAn economical manual, positive-off transfermechanism is a receptacle for the generator set in thecompartment. An approved power cable connectedfrom the load, plugs into this receptacle or the parkutility power receptacle . This ensures both sourcesare NOT connected simultaneously .
An alternative to the receptacle is a manual, positive-off type transfer switch . The positive-off switch allowsresidual voltages of inductive loads (motors, etc .) todecay before switching to the other power source .
WARNING 1supply assembly.
Use only approved power supply assemblies .Never remove grounding pin from powerIncorrect or no ground may cause the
recreational vehicle to be electrically "hot ."
RECONNECTIBLE, SINGLE-PHASEGENERATORVoltage selection on reconnectible single-phasegenerators is for use as 120/240 volts, 3 wire ; or 120volts, 2 wire . Use the connection for two wire servicewhen used for motor starting such as air conditioning .Balance the load when connecting for three wireservice. Current for any one output lead must notexceed nameplate rating . When two or more single-phase circuits are available, divide the load equallyamong them . See Figure 12 .
LOAD CONNECTIONSGenerator set load wires M1, M2, M3 and M4 ter-minate within the junction box . Connect and joinwires within junction box in an approved manner fordesired voltage code . See Figure 12 .
On motor homes which have provisions for usingoutside AC utility power (separate from the electricgenerating set) the neutral as well as the "Hot" leadMUST be completely isolated from the motor homewhen load or power is switched .
ELECTRICGENERATING SET
N
OVERCURRENTPROTECTION
120 V
r
C*JUMPER
r -I-o
I
DOUBLE POLEDOUBLE THROWPOSITIVE OFF
TRANSFER DEVICE
-
C7
0
0
I
IOVERCURRENT
I
IPROTECTION
I120V
0 0-
-
c
120 V
N
120%)
0
O '
TO VEHICLEMAIN BREAKERS
i
L.J3 POLE
DOUBLE THROWPOSITIVE OFF
TRANSFER DEVICE
*FOR 120/240 OPERATION DO NOT USE JUMPER . CONNECT OVERCURRENT PROTECTIONAS SHOWN IN DASHED LINE . SEE RECONNECTION DIAGRAM FIG . 12
Figure 11 . SCHEMATIC OF TRANSFER DEVICE AND OVERLOAD PROTECTION
1 5
120 V
OUTSIDEPOWER
N
120 V
120 V
GROUND
GROUND
0 C
o-
OUTSIDEPOWER
0 Owe
WARNING
supply assembly .
120 VOLT, 2 WIREN
UNGROUNDED LOAD WIRE M1, M3
D(BLACK)
• (JOIN)
4-I
0I-QEWZWO
120 V.(Full nameplate
7 GROUNDED LOAD WIRE(WHITE)
NOTE: Only half nameplaterating can be taken off each120 volt connection .
240 V .
120/240VOLT, 3 WIRE
UNGROUNDED LOAD WIRE (BLACK)
120 V .
20 V.1 .} UNGROUNDED LOAD WIRE (BLACK)
M1
M2, M3 (JOIN)
M4
FIGURE 12. SINGLE-PHASE, "3C" VOLTAGE CODE GENERATOR CONNECTIONS
The operation of a typical transfer device is shown inFigure 11 . In addition to the transfer device, an overcurrent protection device (circuit breaker or fuse)shall be provided between the transfer device and theAC circuit in the motor home . The generator set fieldhas inherent overload protection when any overloadis applied ; frequency will sag which causes outputvoltage to drop and in turn the generator set fielddrops to zero voltage. A ground fault circuit in-terrupter should be installed in the wiring system toprotect all branch circuits .
Use only approved power supply assemblies .Never remove grounding pin from powerIncorrect or no ground may cause the
recreational vehicle to be electrically "hot ."
STARTING CONTROLSRemote control Onan electric sets are designated byan "R" in the model number and provide the operatorto start the set inside the vehicle, etc . Sets with thedesignation "E" are electric start at the set only . Seethe appropriate operator's manual for more specificinformation .
Onan has available remote start-stop controls for theAJ, LK, BF, CCK and NH electric generating sets . AnOnan remote control switch shown in Figure 13includes a start-stop switch with an amber indicatorlamp (lights when set is running) . A deluxe remotecontrol includes a start-stop switch with an amberindicator lamp (lights when set is running), a runningtime meter and a battery condition meter . See Figure14
rating)
1 6
M2, M4(JOIN ANDGROUND)
FRONT SIDE OFREMOTE CONTROL
SWITCH
NOTE: Use 18 gauge orlarger wire for installing theremote start switch .
STOP-START SWITCH (DPDT)(Amber light glows whengenerator set is running)
FIGURE 13 OPTIONAL REMOTE CONTROL SWITCH
FINAL CHECK-OUT PROCEDURE(60 to 80 F ambient)Before the generator set is operated, remove thespark plug wires so the set will not start whencranked . Connect a voltmeter to the battery terminals,and to the battery side of the start solenoid and setframe as shown in Figure 15 .
I
Crank the engine and measure the voltage at the
battery. Then measure the voltage from the startsolenoid to the set frame . Do not allow more than fiveseconds between these readings (use double-pole,double-throw switch as shown) .
STOP-START SWITCH (DPDT)(Amber light glows whengenerator set is running)
FIGURE 14. OPTIONAL DELUXE REMOTE CONTROL
VEHICLE FRAME
FIGURE 15. BATTERY SYSTEM CHECK-OUT CONNECTIONS
17
Subtract voltage at set from measured battery voltageduring the cranking . The difference should not ex-ceed 0.6 volt. If it does, check all connections . Aseparate ground cable may have to be used (samesize as battery cable) .
Alternate TestRemove the spark plug wires, crank the engine andmeasure the cranking speed . Connect a separateground cable from the battery to the set's frame .Crank the engine and again measure the speed . Ifcranking speed increased more than ten percent,check connections and consider a permanent groundcable if it seems necessary .
BATTERY CARETo increase battery life, the operator can perform anumber of routine checks and some preventivemaintenance .
1 . Keep the battery case clean and dry .
2. Make sure the battery cable connections areclean and tight. Use a terminal puller whenremoving cables for any reason .
3 . Coat the battery terminals with a mineral greaseor petroleum jelly to reduce corrosion and oxida-tion .
4. Identify each battery cable to be positive ornegative before making any connection . Alwaysconnect the ground (negative) cable last .
5 . Maintain the electrolyte level by adding water(drinking quality or better) as needed for filling tosplit level marker. (The water ingredient of theelectrolyte evaporates, but the sulphuric acidingredient remains . Therefore, add water, notelectrolyte .)
6 . Avoid overcharging when recharging . Stop theboost charge when the specific gravity is 1 .260and the electrolyte is 80O F (26 .7 0 C) .
Do NOT use unvented batteries with thisgenerator set . Malfunction of the starting-
charging system can produce high charging currents, causingexcessive gassing . An unvented battery can build up sufficientpressure to explode.
BATTERIES AND BATTERY CABLESIn order for the electric generating set to crankefficiently under various operating conditions, thebattery and battery cables must be correctly chosenand installed. Before selecting a battery, be sure theinstallation area is compatible and properly designed .The compartment for the battery must provide:1 . Rigid mounting support .2. A location where accidental acid spills or leaks
won't damage set, battery cables, etc .
3. Provide a minimum of 2 square inches at top and 2square inches at bottom of battery for ventilationpurposes .
Do not disconnect battery cables from batterywhile generator set is cranking or running ;
sparks may cause an explosion.
Mount the battery in a separate compartmentfrom the set or any spark-producing device to
prevent fire or explosion .
WARNING
WARNING
WARNING
Batteries
18
Never disconnect the battery with eitherengine running and never crank both engines
simultaneously.
Battery CablesFor reliable starting, voltage drop from the batteryterminals to the exciter cranking windings of thegenerator should not exceed 0 .12 volts per 100amperes of break-away current . The battery cables inTable 7 will meet this condition if the groundingsystem is adequate. Connect the battery negative toground with the same size cable as used for batterypositive .
Be sure the frame connection (major frame member ifpossible) is sufficient to minimize resistance . Try toavoid a connection at a weld or mechanical joint .
For short distances, one negative battery cable can beused between set and battery rather than separatecables to chassis ground .
Battery SelectionDetermine battery size by the amount of "surge"power required to start the generating set . Select abattery that is at least as large as that specified byOnan .
Locate battery as close as possible to starter andcharging system . Keep the battery well charged andclean. Keep terminals clean and free of corrosion .
Battery SizeOnan recommends one 12-volt, 74 amp hour batteryfor all RV generator sets . In colder temperatureapplications (0 ° to 320 F), one 12-volt, 92 amp hourbattery is recommended for all units . For sub-zerooperation, Onan recommends one 12-volt, 105 amp orlarger capacity battery .
TABLE 7 .RECOMMENDED BATTERY CABLES
* - Distance from battery to set .
* CABLE LENGTHIN FEET (metres) CABLE SIZE
0-10 (0-3) 211-15 (3-4.5) 016-20 (4 .5-6) 000
INSTALLING STANDARD REMOTECONTROLThis control includes a start-stop switch with anindicator lamp. Install as follows :1 . Select switch location . Using Figure 16 as a guide,
drill screw holes and cut holes in RV panel .2. Following national and local electrical codes and
using four insulated wires of predeterminedlength (#18 or larger), connect remote switch toterminals on generator. See Figure 17 .
Ensure that leads from remote switchconnect with corresponding terminals
on generator terminal board .
Don't route DC wires for remote controlthrough conduit containing AC load wir-
ing. Induced voltages may cause erratic operation .
3 . Insert remote switch in hole cutout and securewith two #5 woodscrews supplied with switch .
Seal all holes that might allow noxiousgases from generator set into motor
WARNING
home.
Remote Accessories
f.INAN START
ElECTtIPOWER
STOP
0
GENERATING LAMP(GLOWS WHEN SET
IS RUNNING)
TERMINAL STRIPON GENERATOR
TOP
FIGURE 17 . CONNECTING REMOTE CONTROL (300-0985)
19
W
PANELIN
MOTORHOME
FIGURE 16. MOTOR HOME CUTOUT
PRINTED CIRCUITBOARD TERMINAL
SWITCHTERMINAL FUNCTION
1 1 Ground2 2 Stop
3 3 Start6 6 Lamp
INSTALLING DELUXE REMOTE CONTROL
This control includes a start-stop switch with anindicator lamp, a running time meter and a batterycondition meter . Install and connect as follows :
1 . Select control location . Using Figure 18 as aguide, drill screw holes and cut hole to accom-modate remote switch in panel .
2 . Following national and local electrical codes andusing five insulated wires of predeterminedlength (#18 or larger), connect remote control toterminals on generator . Ensure that leads fromremote control connect to corresponding ter-minals on generator terminal board . See Figure19 .
Don't route DC wires for remote controlthroug conduit containing AC load wir-
ing. Induced voltages may cause erratic operation .3 . Insert remote control in hole cutout and secure
with four #5 woodscrews supplied with switch .
WARNIN G Seal all holes that might allow noxiousgases to enter motor home.
(M2)RUNNING TIME
METER
GENERATING LAMP(GLOWS WHEN SET
IS RUNNING)
(MI)BATTERYCONDITION METER
TERMINAL STRIPON GENERATOR
BACK SIDE OFREMOTE CONTROL 2SWITCH
PRINTED CIRCUITBOARD TERMINAL
TOP
SWITCHTERMINAL FUNCTION
GroundStopStart
BatteryCondition Meter
Lamp and RunningTime Meter
FIGURE 19. CONNECTING DELUXE REMOTE CONTROL (300-0986)
20
FIGURE 18. MOTOR HOME CUTOUT
The RV unit is complete as received except forexhaust components and any other optionalaccessory items which are shipped loose with eachset for installation later . After the initial installation iscompleted, the following steps are necessary beforeactually starting the generator set for the first time .
1 . Install the exhaust system .2. Add oil to the engine .3. Connectfuel lineto engine from fuel supplytank .4 . Connect electrical leads to load circuits .5 . Connect the start stop remote switches (if used) .6 . Connect battery leads between set and battery .
Connect ground lead last .
Vehicle chassis (frame) ground and the battery and generator setground should all be electrically connected to be at 0 groundpotential . All Onan units are designed for negative groundapplication .
FUEL SYSTEMWith set running, check for leaks . Raw fuel will cause
Pre-Start Checks
21
fumes which could EXPLODE . Check around car-buretor and fuel pump inlets . Make sure fuel lines arenot rubbing against anything which could causebreakage .
ELECTRICALAC OutputAll AC leads (Ml, M2, M3 and M4) terminate ingenerator set's junction box. These wires should beconnected to distribution box with multistrand wireenclosed in a flexible conduit . Check all wires (to andfrom the generator set) for fraying and loose connec-tions .
Battery ConnectionsBattery positive (+) connects to start solenoid . Batterynegative (-) connects to location on rear of generator.Check terminals on set for clean and tight connec-tions .
I
WHAT IS A GOOD INSTALLATION?
An owner of an RV electric generating set considers his unit well installed if it produceselectricity quietly, reliably and efficiently .
But how do you - the installer - provide a good installation? Here are some guidelines :
The electric generating set should be mounted on vibration isolators andthe isolators, in turn, firmly mounted to a strong base . The fuel andelectrical lines should be mounted to the frame and connected to the unitthrough flexible sections . Exhaust system components must be installedwith good automotive practice .
Cooling is important . All good RV installations call for a well-ventilatedgenerator compartment (see section on Ventilation), one that coolsadequately while running and completely purges heated air aftershutdown.
A good installation must also be fireproof and vapor-proof . This bulletintells how to accomplish this . . . read it carefully .
Our recommendations for the proper installation of an RV electric generating set are based onyears of experience in the manufacture of generator sets . We offer these recommendationsthrough this technical bulletin so you can be assured the Onan unit selected for yourrecreational vehicle will operate quietly and efficiently for many years to come .
Onan manufactures a complete line of electric power systems from 1 to 750 kW(generator sets • automatic transfer switches • industrial engines), gas-,gasoline- or diesel-driven. For standby power in homes, industrial plants,commercial buildings and institutions . For auxiliary or portable power in boats,recreational vehicles, service trucks and construction equipment .
technical bulletin
RATING FACTORS
FOR
ELECTRIC GENERATING SETS
T-017
ONAN 1400 73RD AVENUE N .E. ° MINNEAPOLIS, MINNESOTA 55432A DIVISION OF ONAN CORPORATION
APRIL 1974
INTRODUCTIONRatings of electric generating sets and operatingconditions must be studied and considered before aunit is selected for a particular installation . Undersome conditions, many considered normal, agenerating set could fall short of the requirements ifcertain operating factors are overlooked . Readthrough the bulletin and follow the examples onselecting a generating set .
FACTORS AFFECTING GENERATING SETOUTPUTEngine power and generator capabilities determineoutput of a generating set . A main factor affectingoutput is the ratio of engine power to power requiredby the generator. Engines with considerable reservehorsepower are only slightly affected by a small lossof engine efficiency. If the engine must operate nearits maximum rated power output, any engine powerloss will also result with a generator output loss .
Among the variable factors affecting generating setoutput is -
°
Fuel°
High Altitude°
High Ambient Temperature
If anyone condition affects engine power enough, therating of the generating set has to be lowered or"derated." Each of these conditions is discussedseparately .
FuelAll Onan generating sets are normally rated on theirstandard fuel capability . However, most Onangasoline-fueled generating sets are adaptable for usewith gaseous fuel . Gas fuel, LP, natural or manufac-tured . can be specified and greatly affects enginepoi-r :1i! loped . An engine will develop nearly thesane horsepower using LP gas as when usinggasoline But for natural or manufactured gas,derating is usually larger. See Table 1 .
Ratings for the different fuels in Table 1 are based onregular-grade gasoline, 2500 BTU/cu . ft . propane,1000 BTU/cu . ft . natural gas, and number 2 dieselfuel . Note sonic engines have higher maximum KWpotentials as high compression engines . Generally,propane and natural gas allow higher compressionratios
1
High AltitudeFrom a practical viewpoint, altitude derating of anyOnan generating set is unnecessary at altitudesbelow 1000 feet . Onan units are rated for conditions atthe factory where the altitude is approximately 900feet. However, lower density air at higher altitudescan cause lower engine power and lower generatorcooling capabilities . The degree of power loss variesfrom engine to engine, but as a general rule, derateabout 4 percent for each 1000 feet increase in altitude .
High Ambient TemperatureWhen an engine is operating in hot air ambients, theengine suffers a proportionate power loss becausehot air is less dense than cool air (similar to higheraltitude) . An average derating value of 1 percent lossfor each 10 F above 60 F is used, disregarding the factsummer ambient temperature for the factory test runis frequently well above 80 F . Derating for highertemperature only is seldom required . . . usuallydone in combination with other derating factors or inborderline cases .
Because life of some engines is shortened when run continuouslyat rated load for long periods of time, some are derated for primepower installations . This is especially true when the engine doesnot have a large horsepower reserve for a given generator size .Contact your Onan distributor .
DETERMINING GENERATING SETRATINGEngine
1 . Find the maximum KW potential of the engine forthe appropriate fuel in Table 1 .
For city-water cooling, add KW shown in the first column tothe engine KW potential (based on deduction of fanhorsepower) .
2 . Use the altitude derating percentage from Table 2or 3 (if over 1000 feet) and add to the followingtemperaturu derating, if any .
3 . Derate the engine 1 percent for each 10 F above60 F ambient temperature .
4 . Total the derating percentages for altitude andtemperature . Sib truet this total from 100 percentand multiply this peer entage times the maximumKW from Step 1 .
TABLE 1 . MAXIMUM KW POTENTIAL OF ENGINE ONLY*
* - Maximum engine KW capability with no deratings for altitude or temperature .Ratings shown are for 60 hertz . Use 83% of these ratings for 50 hertz .
• - This value obtained with high compression engine (do not use propane) .t - This value obtained with high compression engine .
For prime power ratings or application problems, contact your Onan distributor .
Generator
Find the altitude deration in Table 4 . Multiply thepercentage shown in "% of Standard Rating (KW)"column times the generating set rating . This figure isthe maximum generator KW .
2
Actual Generating Set Capacity
Find the lower KW capability from "Engine" and"Generator ." This figure is the actual unit rating forthat particular application . See the following ex-amples .
SPARK IGNITION
Air CooledSeries - Gasoline Propane Nat. Gas
2.5LK 2 .6 2 .5 2 .12.5AJ 2 .5 2 .4 2 .34.000K 5.5 5 .4 5 .0
5.000K 5.5 5 .4 5 .06.5NH 7 .0 6 .0 5 .07.5JB 8.0 7 .8 7 .5
10.000KB 10.2 9 .5 8 .012 .5JC 17.0 16 .0 13 .515.OJC 17 .0 16 .0 13.5
L 15.0 •
Liquid-CooledAdd this KWfor City-Water Gasoline Propane Nat. Gas
Series Cooling
12.5RJC 17.0 16 .5 16.015.ORJC 17.0 16 .5 16.030.OEK 33.0 31 .0 28.0
45.OEM 48.0 45 .0 39 .055 .01<13 3 .0 65.0 58 .0 52 .065.0KB 3.0 65.0 -
70.OKR 3.0 - - 77.085.OKR
-[
4.0 93.0 85 .0 77.04 .0 80.0 t
115.OWA _ 3.0 120.0 119 .0 118.0170.OWB -- 10.0 185.0 180 .0 174.0
10 .0 - - 180.0 t
250.OFT 10 .0 - - 260.0350.OWF 20.0 - - 390.0400.OWK 20.0 - - 480.0
DIESEL
Air-CooledSeries - Diesel
3.0DJA6.ODJB12 .0 DJ C
3 .26 .713 .4
Liquid-CooledSeries
Add this KWfor City-Water
Cooling Diesel
15 .ORDJC 15 .717 .5RDJF 17 .530.ODEH 33 .0
30.ODDA 30.045.ODEF 53 .045 .ODYJ 45.0
50.ODDA 50 .050.ODEG 55 .060.ODYA 1 .1 66 .0
75.ODYC 3 .5 95 .090.ODYC 3.5 95 .0100.ODYD 4.0 131 .0
125.ODYD 4.0 131 .0150.ODYG 6.0 183.0175.ODYG 6 .0 183.0
200.ODYH 6.0 207.0250.ODYB 7 .5 260.0300.ODFT 5.0 300.0
350.ODFU 5.0 370.0400.ODFV 5 .0 405.0450.ODFW 13.0 485.0500.0DFY 10.0 520.0
TABLE 2. GASOLINE, PROPANE AND DIESEL ENGINE ALTITUDE DERATINGS
EXCEPTION : Derating is unnecessary through 5000 feet for series DYA, DYB,DYC, DYD, DYG, DYH, DFU, DFV, DFW and DFY . Use only additionalaltitude when calculating .
TABLE 3. NATURAL GAS ENGINE ALTITUDE DERATINGS
TABLE 4 . GENERATOR ALTITUDE DERATINGS
NOTE : Derate from standby ratings as shown on charts, specification sheetsor unit's nameplate .
3
Altitude AboveSea Level
% of StandardRating (KW)
% Derationper 1000 ft
Total %Deration
1000 100 % 0 02000 95.5 4 .5 4 .53000 91 4 .5 9.04000 87 .5 4 .1 12 .55000 84 4.0 16 .06000 80 4.0 20 .07000 76 4.0 24 .08000 72 4.0 28 .09000 69.5 3 .8 30 .510000 67 3 .7 33 .0
Altitude AboveSea Level
% of StandardRating (KW)
% Derationper 1000 ft
TotalDeration
1000 100 % 0 02000 93 .6 6 .4 6 .43000 87 .9 6 .0 12 .14000 82 .7 5 .7 17 .35000 77 .9 5 .5 22 .16000 72 .5 5 .5 27 .57000 67.2 5 .4 32 .88000 62.2 5 .4 37 .89000 58.6 5.2 41 .410000 55 .9 4 .9 44 .1
Altitude AboveSea Level
% of StandardRating (KW)
% Derationper 1000 ft
TotalDeration
1000 100 % 0 02000 100 0 03000 100 0 04000 97 3 35000 94 3 66000 91 3 97000 88 3 128000 85 3 159000 82 3 1810000 79 3 21
Onan manufactures a complete line of electric power systems from I to 500 KW (generatorsets* automatic transfer switches* industrial engines), gas-, gasoline- or diesel-driven. For standby power in homes, industrial plants, commercial buildings andinstitutions . For auxiliary or portable power in boats, recreational vehicles, servicetrucks and construction equipment .
