Eaton - Compensare

8/21/2019 Eaton - Compensare

1/64

CA08104001E For more information, visit: www.eaton.com/consultants

September 2011

Contents

Power Factor Capacitors and Harmonic Filters35

Sheet 35001

P o w e

r F a c t o r C a p a c i t o

r s

a n d H a r m o n i

c F i l t e

r s

Power Factor Capacitors and Harmonic FiltersCapacitor Application Considerations

Capacitor Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

35.0-2

NEC Code Requirements for Capacitors . . . . . . . . . . . . . . . . . . . . . . .

35.0-2

Capacitor Switching Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

35.0-3

Installing Capacitors in a Plant Distribution System . . . . . . . . . . . . .

35.0-5

Locating Capacitors on Reduced Voltageand Multi-Speed Motor Starters . . . . . . . . . . . . . . . . . . . . . . . . . . . .

35.0-6

Harmonic Considerations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

35.0-7

Capacitor Banks and Transformers Can Cause Resonance . . . . . . . .

35.0-7

Diagnosing a Potential Harmonics Related Problem . . . . . . . . . . . . .

35.0-7

Eliminating Harmonic Problems —Passive and Switched Harmonic Filters . . . . . . . . . . . . . . . . . . . . . .

35.0-8

Motor Power Factor Correction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

35.0-9

Capacitor Application Tables for Motors. . . . . . . . . . . . . . . . . . . . . . .

35.0-11600 Volts AC and Below

Low Voltage Power Factor Correction Capacitor Banks and Harmonic Filters

UNIPUMP Power Factor Correction Capacitors . . . . . . . . . . . . . . . . .

35.1-1

Power Factor Correction Capacitors . . . . . . . . . . . . . . . . . . . . . . . . . .

35.1-3

Harmonic Filtering. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

35.1-3

UNIPAK. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

35.1-4Automatic Power Factor Correction Systems

AUTOVAR 300 Wall-Mounted up to 300 kVAR . . . . . . . . . . . . . . . . . .

35.2-1

AUTOVAR 300 Dimensions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

35.2-2

AUTOVAR 600 Floor-Mounted up to 1200 kVAR. . . . . . . . . . . . . . . . .

35.2-3

AUTOVAR 600 Dimensions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

35.2-6

AUTOVAR Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

35.2-8

AUTOVAR Switched Harmonic Filter Dimensions . . . . . . . . . . . . . . .

35.2-10Active Harmonic Filter-Harmonic Correction Unit (480V Max.)

General Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

35.3-1

Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

35.3-5Transient-Free Statically Switched Capacitor Bank


35.4-1

Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

35.4-4Metal-Enclosed—Medium Voltage

UNIVAR XV (5 kV Class)


35.5-1

Layout Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

35.5-4UNIVAR (15 kV Class)


35.5-6


35.5-7Autovar MV


35.6-2


35.6-6Specifications

See Eaton’s Product Specification Guide

, available on CD or on the Web.

CSI Format: . . . . . . . . . . . . . . . . . . . . . . . . . . 1995 2010

Fixed Power Factor Correction

Equipment—LV(UNIVAR) . . . . . . . . . . . Section 16280A

Section 23 35 33.11

Switched Power Factor CorrectionEquipment—LV (AUTOVAR) . . . . . . . . . . . Section 16280B

Section 23 35 33.13

Switched Harmonic FilterEquipment—LV (AUTOVAR) . . . . . . . . . Section 16280C

Section 26 35 26.11

Switched Power FactorCorrection—MV . . . . . . . . . . . . . . . . . . . Section 16280D

Section 23 35 33.17

Switched Capacitor & Harmonic FilterEquipment—MV (AUTOVAR)

. . . . . . . . . . Section 16280E

Section 23 35 33.19


2/64

5.0-2

For more information, visit: www.eaton.com/consultants

CA08104001E

September 2011

Power Factor Capacitors and Harmonic Filters

Sheet 35

2

3

4

5

6

7

8

9

0

1

2

3

4

5

6

7

8

9

0

1

2

3

Application Considerations

Capacitors

002

Capacitor Selection

There are two basic types of capacitorinstallations: individual capacitors onlinear or sinusoidal loads, and banksof fixed or automatically switched

capacitors at the feeder or substation.

Individual vs. BankedInstallations

Advantages of individual capacitorsat the load:

■

Complete control. Capacitors cannotcause problems on the line duringlight load conditions

■

No need for separate switching.Motor always operates withcapacitor

■

Improved motor performance dueto more efficient power utilizationand reduced voltage drops

■

Motors and capacitors can be easilyrelocated together

■

Easier to select the right capacitor

for the load

■

Reduced line losses

■

Increased system capacity

Advantages of bank installations atthe feeder or substation:

■

Lower cost per kVAR

■

Total plant power factor improved—reduces or eliminates all forms ofkVAR charges

■

Automatic switching ensures exactamount of power factor correction,eliminates overcapacitance andresulting overvoltages

Table 35.0-1. Summary of Advantages/Disadvantages of Individual, Fixed Banks,Automatic Banks, Combination

Selection Criteria

The selection of the type of capacitorinstallation will depend on advantages

and disadvantages of each type andseveral plant variables, including loadtype, load size, load constancy, loadcapacity, motor starting methods andmanner of utility billing.

Load Type

If a facility has many large motors, 50 hpand above, it is usually economical toinstall one capacitor per motor andswitch the capacitor and motor together.If there are many small motors, 1/2 to25 hp, motors can be grouped withone capacitor at a central point in thedistribution system. Often, the bestsolution for plants with large and

small motors is to use both typesof capacitor installations.

Load Size

Facilities with large loads benefit froma combination of individual load,

group load and banks of fixed andautomatically-switched capacitorunits. A small facility, on the otherhand, may require only one capacitorat the service entrance.

Sometimes, only an isolated troublespot requires power factor correction inapplications such as welding machines,induction heaters or DC drives. If aparticular feeder serving a low powerfactor load is corrected, it may raiseoverall plant power factor enough thatadditional capacitors are unnecessary.

Load Constancy

If a facility operates around-the-clockand has a constant load demand, fixedcapacitors offer the greatest economy.If load is determined by eight-hourshifts five days a week, use switchedunits to decrease capacitance duringtimes of reduced load.

Method Advantages Disadvantages

Individualcapacitors

Most technically efficient, most flexible Higher installation and maintenance cost

Fixed bank Most economical, fewer installations Less flexible, requires switches and/orcircuit breakers

Automaticbank

Best for variable loads, preventsovervoltages, low installation cost

Higher equipment cost

Combination Most practical for larger numbersof motors

Least flexible

Load Capacity

If feeders or transformers are over-loaded, or to add additional load toalready loaded lines, correction mustbe applied at the load. If a facility hassurplus amperage, capacitor banks

can be installed at main feeders. Ifload varies a great deal, automaticswitching is a good solution.

Utility Billing

The severity of the local electric utilitytariff for power factor will affect paybackand ROI. In many areas, an optimallydesigned power factor correctionsystem will pay for itself in less thantwo years.

National Electrical CodeRequirements for Capacitors

Nameplate kVAR

: Tolerance +15, –0%.

Discharge resistors

: Capacitors rated at600V and less must reduce the chargeto less than 50V within 1 minute ofde-energization. Capacitors rated above600V must reduce the charge within5 minutes.

Continuous operation

: Up to 135%rated (nameplate) kVAR, includingthe effects of 110% rated voltage(121% kVAR), 15% capacitancetolerance and harmonic voltagesover the fundamental frequency(60 Hz).

Dielectric strength test:

Twice therated AC voltage (or a DC voltage4.3 times the AC rating for non-metallized systems).

Overcurrent Protection

: Fusingbetween 1.65 and 2.5 times ratedcurrent to protect case from rupture.Does not preclude NEC

®

requirementfor overcurrent protection in all threeungrounded conductors.

Note: When capacitor is connected tothe load side of the motor overcurrentprotection, fused disconnects or breakerprotection is not required. Fuses are recom-mended for all other indoor applications.


3/64


35

September 2011


Sheet 35


Switching Devices

003

Capacitor Switching Devices

Low Voltage Capacitor Switching

Circuit breakers and switches for usewith a capacitor must have a currentrating in excess of rated capacitorcurrent to provide for overcurrent fromovervoltages at fundamental frequencyand harmonic currents. The followingpercent of the capacitor-rated currentshould be used as a general guideline:

Fused and unfusedswitches. . . . . . . . . . . . . . . . . . . . 165%

Molded-case breaker orequivalent . . . . . . . . . . . . . . . . . . 150%

DS

II

power circuit breakers . . . . . 135%

Magnum DS powercircuit breaker . . . . . . . . . . . . . . .135%

Contactors:

Open type . . . . . . . . . . . . . . . . . . .135%

Enclosed type . . . . . . . . . . . . . . . .150%

The NEC, Section 460.8(c)(4), requiresthe disconnecting means to be ratednot less than 135% of the rated capacitorcurrent (for 600V and below). SeePage 35.0-4

for more information onLow Voltage Capacitor Switching Devices.

Medium VoltageCapacitor Switching

Capacitance switching constitutessevere operating duty for a circuit

breaker. At the time the breaker opensat near current zero the capacitor isfully charged. After interruption, whenthe alternating voltage on the sourceside of the breaker reaches its oppositemaximum, the voltage that appearsacross the contacts of the open breakeris at least twice the normal peak line-to-neutral voltage of the circuit. If abreakdown occurs across the opencontact the arc is re-established. Dueto the circuit constants on the supplyside of the breaker, the voltage acrossthe open contact can reach three timesthe normal line-to-neutral voltage.After it is interrupted and with

subsequent alternation of the supplyside voltage, the voltage across theopen contact is even higher.

ANSI Standard C37.06 (indoor oillesscircuit breakers) indicates the preferredratings of Eaton’s Type VCP-W vacuumbreaker. For capacitor switchingcareful attention should be paid tothe notes accompanying the table.The definition of the terms are in ANSIStandard C37.04 Article 5.13 (for thelatest edition). The application guideANSI/IEEE Standard C37.012 coversthe method of calculation of the quan-tities covered by C37.06 Standard.

Note that the definitions in C37.04make the switching of two capacitorsbanks in close proximity to the switch-gear bus a back-to-back mode ofswitching. This classification requiresa definite purpose circuit breaker(breakers specifically designed forcapacitance switching).

We recommend that such application

be referred to Eaton.A breaker specified for capacitorswitching should include as applicable:

1. Rated maximum voltage.

2. Rated frequency.

3. Rated open wire line chargingswitching current.

4. Rated isolated cable charging andshunt capacitor switching current.

5. Rated back-to-back cable chargingand back-to-back capacitorswitching current.

6. Rated transient overvoltage factor.

7. Rated transient inrush current andits frequency.

8. Rated interrupting time.

9. Rated capacitive currentswitching life.

10. Grounding of system andcapacitor bank.

Loadbreak interrupter switches

arepermitted by ANSI/IEEE StandardC37.30 to switch capacitance butthey must have tested ratings forthe purpose. Refer to Eaton Type

MVS ratings.

Projects that anticipate requiringcapacitor bank switching or faultinterrupting should identify thebreakers that must have capacitivecurrent switching ratings on the equip-ment schedules and contract drawingsused for the project. Manufacturer’sstandard medium voltage breakersmeeting ANSI C37.xx are not allrated for switching capacitive loads.Special breakers are usually availablefrom vendors to comply with theANSI C37.012 (Application Guidefor Capacitor Current Switching)and other applicable ANSI standards.The use of capacitive current ratedbreakers can affect the mediumvoltage switchgear layout, thus earlyidentification of these capacitive loadsare critical to the design process.

For example, the standard 15 kVEaton 150 VCP-W 500, 1200A vacuum

breaker does not have a capacitivecurrent switching rating; however,the 15 kV Eaton 150 VCP-W 25C,1200A vacuum breaker does have thefollowing general purpose ratings:

■

25A rms cable chargingcurrent switching

■

Isolated shunt capacitor bankswitching current ratings of25A to 600A

■

Definite purpose back-to-backcapacitor switch ratings requiredwhen two banks of capacitors areindependently switched from the15 kV switchgear bus

The special breakers with thesecapacitive current ratings do not haveUL labels, thus UL assembly ratingsare not available.

Contact Eaton for more detailson vacuum breaker and fused loadinterrupter switch products withcapacitive switching current ratingsat medium voltages.


4/64

5.0-4

For more information, visit: www.eaton.com/consultants

CA08104001E

September 2011


Sheet 35

2

3

4

5

6

7

8

9

0

1

2

3

4

5

6

7

8

9

0

1

2

3


Switching Devices

004

Table 35.0-2. Recommended Switching Devices

Table 35.0-2. Recommended Switching Devices (Continued)

Switching device ratings are based on percentage of capacitor-ratedcurrent as indicated (above). The interrupting rating of the switch mustbe selected to match the system fault current available at the pointof capacitor application. Whenever a capacitor bank is purchased

with less than the ultimate kVAR capacity of the rack or enclosure, theswitch rating should be selected based on the ultimate kVAR capacity—not the initial installed capacity.

Capacitor Rating Amperes

kVAR CapacitorRatedCurrent

SafetySwitchFuse Rating

Molded-Case BreakerTrip Rating

PowerBreakerTrip Rating

240V

2.5 5 7.5

6.0 12.0 18.0

15 20 30

15 20 30

15 20 30

10 15 20

24.1 36.1 48.1

40 60 80

40 70 90

40 50 70

25 30 45

60 72.2108

100 125 200

100 125 175

90 100 150

50 60 75

120144180

200 250 300

200 225 275

175 200 250

90100120

217240289

400 400 500

350 400 500

300 350 400

125135

150

301325

361

500 600

600

500 500

600

450 500

500180200225

433480541

800 800 900

700 800 900

600 700 800

240250270

578602650

100010001200

900 9001000

800 9001000

300360375

720866903

120016001500

———

120012001200

480V

2 5 7.5

2.41 6.01 9.0

15 15 15

15 15 15

15 15 15

10 15 20

12.0 18.0 24.0

20 30 40

20 30 40

20 30 40

25 30 35

30.0 36.1 42

50 60 70

50 70 70

50 50 60

40 45 50

48.1 54 60.1

80 90 100

100 100 100

70 80 90

60 75 80

72.2 90.2 96.2

125 150 175

125 150 150

100 125 150

90100120

108120144

200 200 250

175 200 225

150 175 200

125150160

150180192

250 300 350

225 300 300

200 250 300

180200

225

216241

271

400 400

500

350 400

500

300 350

400

240250300

289301361

500 500 600

500 500 600

400 400 500

320360375

385433451

700 800 800

600 700 700

600 600 600

400450

481541

800 900

800 900

800 800

Capacitor Rating Amperes

kVAR CapacitorRatedCurrent

SafetySwitchFuse Rating

Molded-Case BreakerTrip Rating

PowerBreakerTrip Rating

600V

5 7.5 10

4.8 7.2 9.6

15 15 20

15 15 15

15 15 15

15 20 25

14.4 19.2 24.1

25 35 40

30 30 40

20 30 40

30 35 40

28.9 33.6 38.5

50 60 70

50 50 70

40 50 70

45 50 60

43.3 48.1 57.8

80 80100

70100100

70 70 90

75 80100

72.2 77.0 96.2

125150175

125125150

100125150

120125

150

115120

144

200200

250

175200

225

175175

200160180200

154173192

300300350

250300300

225250300

225240250

217231241

400400400

350350400

300350350

300320360

289306347

500600600

500500600

400500500

375400450

361385433

600700800

600600700

500600600


5/64


35

September 2011


Sheet 35


Capacitor Installation

005

Installing Capacitors in aPlant Distribution System

At the Load

Because capacitors act as kVAR

generators, the most efficient placeto install them is directly at the motor,where kVAR is consumed. Threeoptions or other low power factor loadexist for installing capacitors at themotor. Use Figures 35.0-1

–

35.0-7

, andthe information below to determinewhich option is best for each motor.

Location A—Motor Side of Overload Relay

■

New motor installations in whichoverloads can be sized in accor-dance with reduced current draw

■

Existing motors when no overloadchange is required

Location B—Line Side of Overload Relay

■

Existing motors when overloadrating surpasses code (see Appendixfor NEC code requirements)

Location C—Line Side of Starter

■

Motors that are jogged, plugged,reversed

■

Multi-speed motors

■ Starters with open transition andstarters that disconnect/reconnect

capacitor during cycle

■ Motors that start frequently

■ Motor loads with high inertia, wheredisconnecting the motor with thecapacitor can turn the motor intoa self-excited generator

At the Service FeederWhen correcting entire plant loads,capacitor banks can be installed at theservice entrance, if load conditionsand transformer size permits. If theamount of correction is too large,some capacitors can be installed atindividual motors or branch circuits.

When capacitors are connected to thebus, feeder, motor control center orswitchboard, a disconnect and over-current protection must be provided.

Figure 35.0-2. Installing Capacitors Online Refer to Pages 35.0-3 and 35.0-14 for

switching device considerations andconductor sizing.

Locating Capacitors on Motor Circuits

Figure 35.0-1. Locating Capacitors on Motor Circuits

Main Busor Feeder

Fused Switch orCircuit Breaker

CapacitorBank

Motor

MotorFeed

MotorStarter

Fused SafetySwitch or Breaker

Install atLocation:

CapacitorC

CapacitorB

CapacitorA

ThermalOverload

B AC


6/64

5.0-6

For more information, visit: www.eaton.com/consultants CA08104001E

September 2011


Sheet 35

2

3

4

5

6

7

8

9

0

1

2

3

4

5

6

7

8

9

0

1

2

3


Locating Capacitors006

Locating Capacitors on Reduced Voltage and Multi-Speed Motors

Figure 35.0-3. Autotransformer—Closed Transition

Note: Connect capacitor on motor side of starting contacts (2, 3, 4)at points A–B–C.

Figure 35.0-4. Series Resistance Starting

Note: Connect capacitor on motor side of starting contactor (1, 2, 3)at points A–B–C.

Figure 35.0-5. Part-Winding Starting

Note: Connect capacitor on motor side of starting contacts (1, 2, 3)at points A–B–C.

Figure 35.0-6. Wye-Delta Starting

Note: Connect capacitor on motor side of starting contacts (1, 2, 3)

at points A–B–C.

Figure 35.0-7. Reactor Starting

Note: Connect capacitor on motor side of starting contactor (1, 2, 3)at points A–B–C.

MotorStator

5

4

3

2

1

C

B

A

6

7Line

Start: Close 6-7-2-3-4

Transfer: Open 6-7Run: Close 1-5

MotorStator

1

2

3 A

B

6 9

5 8

4 7

Line

Start: Close 1-2-3Second Step: Open 4-5-6Third Step: Close 7-8-9

C

MotorStatorStart: Close 1-2-3

Run: Close 4-5-6

A

B

C2

1

3Line

6

5

4

1

2

Line

Wye Start: Close 1-2-3-7-8Delta Run: Close 1-2-3-4-5-6

4

B 5

A

7

8

6

3

C

MotorStator

MotorStator

A

Line

3

B2

C1

6

5

4

Start: Close 1-2-3Run: Close 4-5-6


7/64


35September 2011


Sheet 35


Harmonic Considerations007

Harmonic Considerations

A discussion of power system harmonics is incompletewithout discussing the effects of power factor correctioncapacitors. In an industrial plant containing power factorcorrection capacitors, harmonic currents and voltages can

be magnified considerably due to the interaction of thecapacitors with the service transformer. This is referredto as harmonic resonance or parallel resonance . For a typicalplant containing power factor correction capacitors, theresonant frequency (frequency at which amplificationoccurs) normally falls in the vicinity of the 5th to the 13thharmonic. Because nonlinear loads typically inject currentsat the 5th, 7th, 11th and 13th harmonics, a resonant ornear-resonant condition will often result if drives andcapacitors are installed on the same system, producingthe symptoms and problems with blown fuses, damagedcapacitors or failures in other portions of the electricaldistribution system.

Note: Capacitors themselves do not cause harmonics, but onlyaggravate potential harmonic problems. Often, harmonic-relatedproblems do not “show up” until capacitors are applied for power

factor correction.

It is a common misconception that the problem of applyingcapacitors in harmonic environments is limited to problemscaused for the capacitor itself—that the capacitor’s lowerimpedance at higher frequencies causes a current overloadinto the capacitor and, therefore, must be removed. However,the capacitor/harmonics problem must be viewed from apower system standpoint. The capacitor-induced increase ofharmonic voltages and currents on a plant’s system may becausing problems while the capacitor itself remains within itsacceptable current rating.

Capacitor Banks and TransformersCan Cause Resonance

Capacitors and transformers can create dangerousresonance conditions when capacitor banks are installedat the service entrance. Under these conditions, harmonicsproduced by nonlinear devices can be amplified many fold.

Problematic amplification of harmonics becomes morelikely as more kVAR is added to a system which contains asignificant amount of nonlinear load.

An estimate of the resonant harmonic frequency is found byusing the following formula:

If h is near the values of the major harmonics generatedby a nonlinear device—i.e., 3, 5, 7, 11—then the resonancecircuit will greatly increase harmonic distortion.

For example, if a plant has a 1500 kVA transformer with a5-1/2% impedance and the short-circuit rating of the utility is48,000 kVA, then kVAsys would equal 17,391 kVA.

If 350 kVAR of capacitors were used to improve power factor,h would be:

Because h falls right on the 7th harmonic, these capacitorscould create a harmful resonance condition if nonlineardevices were present in the factory. In this case the capacitorsshould be applied only as harmonic filtering assemblies.

Diagnosing a PotentialHarmonics Related Problem

Negative symptoms of harmonics on plant equipmentinclude blown fuses on capacitors, reduced motor life,false or spurious operations of fuses or circuit breakers,decreased life or increased noise in transformers ormis-operation of electronic or microprocessor controls.If one or more of these symptoms occurs with regularity,then the following steps should be taken.

1. If the plant contains power factor correction capacitors,the current into the capacitors should be measuredusing a ‘true rms’ current meter. If this value is higherthan the capacitor’s rated current at the system voltage(by >5% or so), the presence of harmonic voltagedistortion is likely.

2. Conduct a paper audit of the plant’s harmonic-producingloads and system configuration. This analysis startswith the gathering of kVA or horsepower data on all themajor nonlinear devices in the plant, all capacitors, andrating information on service entrance transformer(s).This data is analyzed to determine whether theconditions are present to create unfavorable levelsof harmonics.

3. If the electrical distribution system is complex—e.g.,

multiple service entrances, distributed capacitors—or if the paper audit is incomplete or considered to betoo burdensome, the most definitive way to determinewhether harmonics are causing a problem is through anon-site plant audit. This audit involves an inspection ofthe electrical system layout and connected loads, as wellas harmonic measurements taken at strategic locations.This data can then be assembled and analyzed to obtaina clear and concise understanding of the power system.

hkVAsyskVAR

------------------=

kVAsys Short-Circuit Capacity of the System=

h The Harmonic Number referred to a 60 Hz Base=

kVAR Amount of Capacitor kVAR on the Line=

h 17,391350

------------------ 49.7 7.0= = =


8/64

5.0-8


September 2011


Sheet 35

2

3

4

5

6

7

8

9

0

1

2

3

4

5

6

7

8

9

0

1

2

3


Harmonic Considerations008

Eliminating HarmonicProblems

When power factor correction isrequired in the presence of nonlinearloads, or the amount of harmonic

distortion must be reduced to solvepower quality problems or avoidpenalties, the most reliable, lowestcost solution is often realized withthe use of harmonic filters.

Passive and SwitchedHarmonic Filters

A shunt harmonic filter (seeFigure 35.0-8) is, essentially, a powerfactor correction capacitor combinedwith a series iron core reactor. A filterprovides power factor correction atthe fundamental frequency and

becomes an inductance (like a motor)at frequencies higher than its “tuningpoint.” Most harmonic filters are tunedbelow the 5th harmonic. Therefore, thefilter provides an inductive impedancepath to those currents at harmonicfrequencies created by nearly allthree-phase non-linear loads (5th, 7th,11th, 13th, etc.). Because the filter isnot capacitive at these frequencies, theplant electrical system can no longerresonate at these frequencies and cannot magnify the harmonic voltagesand currents .

A shunt harmonic filter thereforeaccomplishes three things:

1. Provides power factor correction.

2. Prevents harmonic overvoltagesdue to resonance.

3. Reduces voltage harmonicdistortion and transformerharmonic loading at frequenciesabove its tuning point.

In some circumstances, a harmonicresonance condition may accruegradually over time as capacitors andnonlinear loads are installed in a plant.The replacement of such capacitorswith harmonic filters in order tocorrect a problem may be prohibitivelyexpensive. Custom-designed harmonicfilters which are able to eliminateproblems associated with resonanceat any particular frequency while

providing an extremely low amountof power factor correction capacitance.These low kVAR filters are thereforeable to provide the same amount offiltering capacity as a much largerconventional filter, but at a lower cost.

Solutions for Systemswith High Harmonics

If the plant loads vary, then a switchedcapacitor/filter bank is recommended.For systems with widely varying loadswhere harmonic cancellation is theprimary goal, a Harmonic Correction

Unit (HCU) is recommended.

Figure 35.0-8. Shunt Harmonic Filter

Phase

A

B

C

Reactor

CapacitorBank


9/64


35September 2011


Sheet 35


Motor Power Factor Correction009

Motor Power FactorCorrection

Tables 35.0-3 and 35.0-4 containsuggested maximum capacitor ratingsfor induction motors switched with

the capacitor. The data is general innature and representative of generalpurpose induction motors of standarddesign. The preferable means to selectcapacitor ratings is based on the“maximum recommended kVAR”information available from the motormanufacturer. If this is not possibleor feasible, the tables can be used.

An important point to rememberis that if the capacitor used with themotor is too large, self-excitation maycause a motor-damaging overvoltagewhen the motor and capacitor combi-nation is disconnected from the line.

In addition, high transient torquescapable of damaging the motor shaftor coupling can occur if the motoris reconnected to the line whilerotating and still generating a voltageof self-excitation.

Definitions

kVAR—rating of the capacitor inreactive kilovolt-amperes. This valueis approximately equal to the motorno-load magnetizing kilovars.

% AR—percent reduction in linecurrent due to the capacitor. A capacitorlocated on the motor side of the over-load relay reduces line current throughthe relay. Therefore, a different over-load relay and/or setting may benecessary. The reduction in line currentmay be determined by measuring linecurrent with and without the capacitoror by calculation as follows:

If a capacitor is used with a lower kVARrating than listed in tables, the % ARcan be calculated as follows:

The tables can also be used for othermotor ratings as follows:

A. For standard 60 Hz motorsoperating at 50 Hz:

kVAR = 1.7–1.4 of kVAR listed% AR= 1.8–1.35 of % AR listed

B. For standard 50 Hz motorsoperating at 50 Hz:

kVAR = 1.4–1.1 of kVAR listed% AR= 1.4–1.05 of % AR listed

C. For standard 60 Hz wound-rotor

motors:kVAR= 1.1 of kVAR listed% AR= 1.05 of % AR listed

Note: For A, B, C, the larger multipliers applyfor motors of higher speeds; i.e., 3600 rpm =1.7 mult., 1800 rpm = 1.65 mult., etc.

To derate a capacitor used on a systemvoltage lower than the capacitorvoltage rating, such as a 240Vcapacitor used on a 208V system,use the following formula:

For the kVAC required to correct thepower factor from a given value ofCOS φ1 to COS φ2, the formula is:

kVAC = kW (tan phase1–tan phase2)

Capacitors cause a voltage rise.At light load periods the capacitivevoltage rise can raise the voltage atthe location of the capacitors to anunacceptable level. This voltage risecan be calculated approximately bythe formula

MVAR is the capacitor ratingand MVASC is the system short-circuit capacity.

With the introduction of variable speeddrives and other harmonic currentgenerating loads, the capacitorimpedance value determined mustnot be resonant with the inductivereactances of the system. This matteris discussed further under the heading

“Harmonics and Nonlinear Loads.”

% AR 100 100(Original PF)

(Improved PF)−−−−−−−−−−−−−−−−−−−−−−−−×–=

% AR Listed % AR Actual kVARkVAR in Table−−−−−−−−−−−−−−−−−−−−−−−−×=

Actual kVAR =

Nameplate kVARApplied Voltage( )2

Nameplate Voltage( )2-------------------------------------------------------×

% VRMVAr

MVASC−−−−−−−−−−−−=


10/64

5.0-10


September 2011


Sheet 35

2

3

4

5

6

7

8

9

0

1

2

3

4

5

6

7

8

9

0

1

2

3


Motor Power Factor Correction010

Useful Capacitor Formulas

Nomenclature: C = Capacitance in µFV = VoltageA = CurrentK = 1000

A. Additional Data

1. Simplified Voltage Rise:

2. Losses Reduction:

3. Operation at other than rated voltage and frequencyNote: Use of voltages and frequencies above the ratedvalues can be dangerous. Consult the factory for anyunusual operating conditions.

a. Reduced Voltage:

b. Reduced Frequency:

c. Examples:

(a) Voltage Reduction:

(b) Frequency Reduction:

B. Miscellaneous

% L.R.kVAR (Cap.) % Transformer Reactance×

kVA(Transformer)----------------------------------------------------------------------------------------------------------------=

% L.R. 100 – 100Original PF

Improved PF-----------------------------------

2=

Actual kVAR (Output) Rated kVARActual Voltage

Rated Voltage-----------------------------------------

2=

Actual kVAR Rated kVARActual Freq.

Rated Freq.---------------------------------

2=

kVAR (208) kVAR (240)208

240----------

2 0.75= =

(10 kVAR @ 240V 7.5 kVAR @ 208V)=

kVAR (120) kVAR (240)120

240----------

2 0.25= =

(10 kVAR @ 240V 2.5 kVAR @ 120V)=

kVAR (50 Hz) kVAR (60 Hz)50

60------

0.83= =

(60 kVAR @ 480V 60 Hz 50 kVAR, 480V, 50 Hz)=

Single-

Phase

Three-

Phase

2. kW =

3. kVA =

4. Line Current Amperes =

1. Power Factor Cos θ kWkV A-----------= =

Tan θ kW

kVA

-----------=

V A PF××103

---------------------------3 V× A× PF×

103-----------------------------------------

V A×103

--------------3 V× A×

103----------------------------

kVA 103×V

---------------------------

kVA 103×3 V×

---------------------------

5. Capacitor Current (Amperes) 2πf ( )CV 10–6×=

also:kVAR 103×

V-------------------------------

kVAR 103×3 V×

-------------------------------

6. kVAkW

PF--------

(kW Motor Input)=

7. kW (Motor Input)hp 0.746×efficiency

----------------------------=

8. Approx. Motor kVA Motor hp (at full load)=


11/64


35.0September 2011


Sheet 35


Application Considerations—Motors011

Table 35.0-3. Suggested Maximum Capacitor Ratings

For use with three-phase, 60 Hz NEMA Classification B motors to raise full load power factor to approximately 95%.

InductionMotor hpRating

Number of Poles and Nominal Motor Speed in RPM

2—3600 RPM 4—1800 RPM 6—1200 RPM 8—900 RPM 10—720 RPM 12—600 RPM

CapacitorkVAR

CurrentReduction%

CapacitorkVAR

CurrentReduction%

CapacitorkVAR

CurrentReduction%

CapacitorkVAR

CurrentReduction%

CapacitorkVAR

CurrentReduction%

CapacitorkVAR

CurrentReduction%

Used for High Efficiency Motors and Older Design (Pre “T-Frame”) Motors

3 5 7.5

1.5 2 2.5

141211

1.5 2 2.5

151312

1.5 2 3

201715

2 3 4

272522

2.5 4 5

353230

3 4 6

413734

10 15 20

3 4 5

10 9 9

3 4 5

111010

3 5 6

141312

5 6 7.5

211816

6 8 9

272321

7.5 9 12.5

312725

25 30 40

6 7 9

9 8 8

6 7 9

10 9 9

7.5 910

111110

9 10 12.5

151413

10 12.5 15

201816

15 17.5 20

232220

50 60 75

12.51517.5

8 8 8

101517.5

9 8 8

12.51517.5

101010

15 17.5 20

121110

20 22.5 25

151514

25 27.5 35

191918

100125150

22.527.530

8 8 8

202530

8 8 8

253035

9 9 9

27.5 30 37.5

101010

35 40 50

131312

40 50 50

171615

200

250300

40

5060

8

8 8

37.5

4550

8

7 7

40

5060

9

8 8

50

60 60

10

9 9

60

70 80

12

1111

60

75 90

14

1312

350400450500

60757575

8 8 8 8

60607575

7 6 6 6

75758085

8 8 8 8

75 85 90100

9 9 9 9

90 95100100

1010 9 9

95100110120

11111110

T-Frame NEMA® “Design B” Motors

2 3 5

1 1.5 2

141414

1 1.5 2.5

242322

1.5 2 3

302826

2 3 4

423831

2 3 4

404040

3 4 5

504949

7.5 10 15

2.5 4 5

141412

3 4 5

201818

4 5 6

212120

5 6 7.5

282724

5 7.5 8

383632

6 8 10

453834

20 25 30

6 7.5 8

121211

6 7.5 8

171716

7.5 8 10

191919

9 10 15

232322

10 12.5 15

292524

12.5 17.5 20

303030

40 50 60

12.5 15 17.5

121212

15 17.5 20

161515

15 20 22.5

191917

17.5 22.5 25

212120

20 22.5 30

242422

25 30 35

303028

75100125

20 22.5 25

121110

25 30 35

141412

25 30 35

151212

30 35 40

171614

35 40 45

211515

40 45 50

191717

150200250

30 35 40

101011

40 50 60

121110

40 50 60

121110

50 70 80

141413

50 70 90

131313

60 90100

171717

300350400

45 50 75

111210

70 75 80

10 8 8

75 90100

121212

100120130

141313

100120140

131313

120135150

171515

450500

80100

8 8

90120

8 9

120150

1012

140160

1212

160180

1413

160180

1515


12/64

5.0-12


September 2011


Sheet 35

2

3

4

5

6

7

8

9

0

1

2

3

4

5

6

7

8

9

0

1

2

3


Application Considerations—Motors012

Table 35.0-4. Suggested Capacitor Ratings, in kVARs, for NEMA Design C, D and Wound-Rotor Motors

Note: Applies to three-phase, 60 Hz motors when switched with capacitors as single unit.Note: Use motor manufacturer’s recommended kVAR as published in the performance data sheets for specific motor types:drip-proof, TEFC, severe duty, high efficiency and NEMA design.

Table 35.0-5. 2400 Volts and 4160 Volt Motors NEMA Design B

Table 35.0-6. NEMA Design B and C 2300 and 4000V Motors (after 1956)

InductionMotor Rating (hp)

Design C Motor Design D Motor1200 r/Minimum

Wound-RotorMotor1800 and 1200 r/Minimum 900 r/Minimum

15 20 25

5 5 6

5 6 6

5 6 6

5.5 7 7

30 40 50

7.51012

91215

101215

111317.5

60 75100

17.51927

1822.527

1822.530

202533

125150200

3537.545

37.54560

37.54560

405065

250300

5465

7090

7075

7585

Nominal Motor Speed in RPM and Number of Poles

InductionMotorRating (hp)

3600 RPM 2 1800 RPM 4 1200RPM 6 900 RPM 8 720 RPM 10 600 RPM 12kVAR Current

Reduction %kVAR Current





Reduction %

100 120 150 200

25 25 25 50

8777

25 25 25 50

10 9 8 8

25 25 25 50

1110 9 9

25 25 25 50

1110 9 9

25 25 25 50

12111110

25 50 50 75

16151414

250 300 350 400

50 50 50 75

7766

50 50 50 75

7 7 6 6

50 75 75 75

8 8 8 7

75 75 75100

9 9 9 9

75 75 75100

10 9 9 9

75100100100

14131211

450 500 600 700

75 75 75100

6555

75 75100100

6 6 6 6

75100100125

6 6 6 6

100125125150

9 9 8 8

100125150150

9 9 9 8

125125150150

10 9 9 8

800 90010001250

100125150200

5555

150150200200

6 6 6 6

150200250250

6 6 5 5

150200250300

7 7 6 6

200250250300

8 8 7 6

200250250300

8 8 7 6

Nominal Motor Speed in RPM and Number of Poles

InductionMotorRating (hp)

3600 RPM 2 1800 RPM 4 1200 RPM 6 900 RPM 8 720 RPM 10 600 RPM 12

kVAR CurrentReduction %






NEMA Design B 2300 and 4000V Motors (after 1956)

100 120 150 200 250

25 25 25 25 30

77777

25 25 25 25 30

10 9 8 6 5

25 25 25 50 50

1110 8 8 8

25 25 25 50 50

1110 9 9 9

25 25 50 50 75

1211111010

25 50 50 75100

1715151414

300 350 400 450

500

50 50 50 75

75

7655

5

50 50 50 50

75

5 5 5 5

5

75 75 75 75

100

8 8 6 6

6

75 75100100

125

9 9 9 8

8

75 75100100

125

9 9 9 8

8

100100100100

125

121110 8

8

600 700 800 90010001250

75100100125150200

555555

100100125150200200

5 5 5 5 5 5

100100125200250250

5 5 5 5 5 5

125125150200250300

7 7 7 6 6 6

125150150250250300

8 8 8 7 7 6

125150150250250300

8 8 8 7 7 6

NEMA Design C 2300 and 4000V Motors (after 1956)

100 125 150 200 250

—————

—————

2525255050

1111 9 9 8

25 25 25 50 50

1111 9 9 9

25 25 50 50 50

1111 9 9 9

25 25———

1111———

—————

—————

300 350

——

——

5050

6 6

75 75

9 8

75 75

9 9

——

——

——

——


13/64


35.0September 2011


Sheet 35


Application Considerations—System kVAR Selection013

Table 35.0-7. Multipliers to Determine Capacitor Kilovars Required for Power Factor Correction

Note: To obtain required capacitor kVAR:1. Get PF correction factor from Table 35.0-7 above.2. Required capacitor kVAR = kW load x factor.

How Much kVAR Do I Need?The unit for rating power factorcapacitors is kVAR, equal to 1000volt-amperes of reactive power. ThekVAR rating signifies how much reac-tive power the capacitor will provide.

Instructions:

1. Find the present power factorin column 1.

2. Read across to optimum powerfactor column.

3. Multiply that number by

kW demand.

Example:

If your plant consumed 410 kW, wascurrently operating at 73% power factorand you wanted to correct power factorto 95%, you would:

1. Find 0.73 in column 1.

2. Read across to 0.95 column.

3. Multiply 0.607 by 410 = 249(round to 250).

4. You need 250 kVAR to bring your

plant to 95% power factor.

If you don’t know the existing powerfactor level of your plant, you willhave to calculate it before using thetable above. To calculate existingpower factor:kW divided by kVA = Power Factor.

OriginalPowerFactor

Corrected Power Factor

0.80 0.81 0.82 0.83 0.84 0.85 0.86 0.87 0.88 0.89 0.90 0.91 0.92 0.93 0.94 0.95 0.96 0.97 0.98 0.99 1.0

0.500.51

0.520.530.54

0.9820.937

0.8930.8500.809

1.0080.962

0.9190.8760.835

1.0340.989

0.9450.9020.861

1.0601.015

0.9710.9280.887

1.0861.041

0.9970.9540.913

1.1121.067

1.0230.9800.939

1.1391.094

1.0501.0070.966

1.1651.120

1.0761.0330.992

1.1921.147

1.1031.0601.019

1.2201.175

1.1311.0881.047

1.2481.203

1.1591.1161.075

1.2761.231

1.1871.1441.103

1.3061.261

1.2171.1741.133

1.3371.292

1.2481.2051.164

1.3691.324

1.2801.2371.196

1.4031.358

1.3141.2711.230

1.4401.395

1.3511.3081.267

1.4811.436

1.3921.3491.308

1.5291.484

1.4401.3971.356

1.5891.544

1.5001.4571.416

1.7321.687

1.6431.6001.559

0.550.560.570.580.59

0.7690.7300.6920.6550.619

0.7950.7560.7180.6810.645

0.8210.7820.7440.7070.671

0.8470.8080.7700.7330.697

0.8730.8340.7960.7590.723

0.8990.8600.8220.7850.749

0.9260.8870.8490.8120.776

0.9520.9130.8750.8380.802

0.9790.9400.9020.8650.829

1.0070.9680.9300.8930.857

1.0350.9960.9580.9210.885

1.0631.0240.9860.9490.913

1.0931.0541.0160.9790.943

1.1241.0851.0471.0100.974

1.1561.1171.0791.0421.006

1.1901.1511.1131.0761.040

1.2271.1881.1501.1131.077

1.2681.2291.1911.1541.118

1.3161.2771.2391.2021.166

1.3761.3371.2991.2621.226

1.5191.4801.4421.4051.369

0.600.610.620.630.64

0.5830.5490.5160.4830.451

0.6090.5750.5420.5090.474

0.6350.6010.5680.5350.503

0.6610.6270.5940.5610.529

0.6870.6530.6200.5870.555

0.7130.6790.6460.6130.581

0.7400.7060.6730.6400.608

0.7660.7320.6990.6660.634

0.7930.7590.7260.6930.661

0.8210.7870.7540.7210.689

0.8490.8150.7820.7490.717

0.8770.8430.8100.7770.745

0.9070.8730.8400.8070.775

0.9380.9040.8710.8380.806

0.9700.9360.9030.8700.838

1.0040.9700.9370.9040.872

1.0411.0070.9740.9410.909

1.0821.0481.0150.9820.950

1.1301.0961.0631.0300.998

1.1901.1561.1231.0901.068

1.3331.2991.2661.2331.201

0.650.660.670.680.69

0.4190.3880.3580.3280.299

0.4450.4140.3840.3540.325

0.4710.4400.4100.3800.351

0.4970.4660.4360.4060.377

0.5230.4920.4620.4320.403

0.5490.5180.4880.4580.429

0.5760.5450.5150.4850.456

0.6020.5710.5410.5110.482

0.6290.5980.5680.5380.509

0.6570.6260.5960.5660.537

0.6850.6540.6240.5940.565

0.7130.6820.6520.6220.593

0.7430.7120.6820.6520.623

0.7740.7430.7130.6830.654

0.8060.7750.7450.7150.686

0.8400.8090.7790.7490.720

0.8770.8460.8160.7860.757

0.9180.8870.8570.8270.798

0.9660.9350.9050.8750.846

1.0260.9950.9650.9350.906

1.1691.1381.1081.0781.049

0.700.710.720.730.74

0.2700.2420.2140.1860.159

0.2960.2680.2400.2120.185

0.3220.2940.2660.2380.211

0.3480.3200.2920.2640.237

0.3740.3460.3180.2900.263

0.4000.3720.3440.3160.289

0.4270.3990.3710.3430.316

0.4530.4250.3970.3690.342

0.4800.4520.4240.3960.369

0.5080.4800.4520.4240.397

0.5360.5080.4800.4520.425

0.5640.5360.5080.4800.453

0.5940.5660.5380.5100.483

0.6250.5970.5690.5410.514

0.6570.6290.6010.5730.546

0.6910.6630.6350.6070.580

0.7280.7000.6720.6440.617

0.7690.7410.7130.6850.658

0.8170.7890.7610.7330.706

0.8770.8490.8210.7930.766

1.0200.9920.9640.9360.909

0.750.760.770.780.79

0.1320.1050.0790.0520.026

0.1580.1310.1050.0780.052

0.1840.1570.1310.1040.078

0.2100.1830.1570.1300.104

0.2360.2090.1830.1560.130

0.2620.2350.2090.1820.156

0.2890.2620.2360.2090.183

0.3150.2880.2620.2350.209

0.3420.3150.2890.2620.236

0.3700.3430.3170.2900.264

0.3980.3710.3450.3180.292

0.4260.3990.3730.3460.320

0.4560.4290.4030.3760.350

0.4870.4600.4340.4070.381

0.5190.4920.4660.4390.413

0.5530.5260.5000.4730.447

0.5900.5630.5370.5100.484

0.6310.6040.5780.5510.525

0.6790.6520.6260.5990.573

0.7390.7120.6850.6590.633

0.8820.8550.8290.8020.776

0.800.810.820.830.84

0.000 0.0260.000

0.0520.0260.000

0.0780.0520.0260.000

0.1040.0780.0520.0260.000

0.1300.1040.0780.0520.026

0.1570.1310.1050.0790.053

0.1830.1570.1310.1050.079

0.2100.1840.1580.1320.106

0.2380.2120.1860.1600.134

0.2660.2400.2140.1880.162

0.2940.2680.2420.2160.190

0.3240.2980.2720.2460.220

0.3550.3290.3030.2770.251

0.3870.3610.3350.3090.283

0.4210.3950.3690.3430.317

0.4580.4320.4060.3800.354

0.4990.4730.4470.4210.395

0.5470.5210.4950.4690.443

0.6090.5810.5550.5290.503

0.7500.7240.6980.6720.646

0.850.860.87

0.880.89

0.000 0.0270.000

0.0530.0260.000

0.0800.0530.027

0.000

0.1080.0810.055

0.0280.000

0.1360.1090.083

0.0560.028

0.1640.1370.111

0.0840.056

0.1940.1670.141

0.1140.086

0.2250.1980.172

0.1450.117

0.2570.2300.204

0.1770.149

0.2910.2640.238

0.2110.183

0.3280.3010.275

0.2480.220

0.3690.3420.316

0.2890.261

0.4170.3900.364

0.3370.309

0.4770.4500.424

0.3970.369

0.6200.5930.567

0.5400.512

0.900.910.920.930.94

0.000 0.0280.000

0.0580.0300.000

0.0890.0610.0310.000

0.1210.0930.0630.0320.000

0.1550.1270.0970.0660.034

0.1920.1640.1340.1030.071

0.2330.2050.1750.1440.112

0.2810.2530.2230.1920.160

0.3410.3130.2830.2520.220

0.4840.4560.4260.3950.363

0.950.960.970.980.99

0.000 0.0370.000

0.0790.0410.000

0.1260.0890.0480.000

0.1860.1490.1080.0600.000

0.3290.2920.2510.2030.143


14/64

5.0-14


September 2011


Sheet 35

2

3

4

5

6

7

8

9

0

1

2

3

4

5

6

7

8

9

0

1

2

3


Application Considerations—Capacitors014

Table 35.0-8. Recommended Feeder Wire Sizes, Switches and Fuses for Three-Phase, 60 Hz Capacitors

90°C Copper Type THHN, XHHW or equivalent, applied at 75°C ampacity. Rate current based on operation at rated voltage, frequency and kVAR.Consult National Electrical Code for other wire types. Above size based on 30°C Ambient Operation. (Refer to NEC Table 310.16.)

Note: Fuses furnished within Capacitor Assembly may be rated at higher value than shown in this table. The table is correct for fieldinstallations and reflects the manufacturer’s suggested rating for overcurrent protection and disconnect means in compliance with theNational Electrical Code. Fuses used internally in capacitor banks are not sized by this chart.

kVAR 240V 480V 600V

Current(Amps)

WireSize

Fuse(Amps)

Switch(Amps)

Current(Amps)

WireSize

Fuse(Amps)

Switch(Amps)

Current(Amps)

WireSize

Fuse(Amps)

Switch(Amps)

0.5 1

1.5

1.2 2.4

3.6

1414

14

3 6

6

30 30

30

— 1.2

1.8

—14

14

— 3

3

— 30

30

— 1.0

1.4

—14

14

— 3

3

— 30

30

2 2.5 3

4.8 6.0 7.2

141414

10 10 15

30 30 30

2.4 3.0 3.6

141414

6 6 6

30 30 30

1.9 2.4 2.9

141414

6 6 6

30 30 30

4 5 6

9.6 12 14

141414

20 20 25

30 30 30

4.8 6.0 7.2

141414

10 10 15

30 30 30

3.8 4.8 5.8

141414

10 10 10

30 30 30

7.5 8 10

18 19 24

121010

30 35 40

30 60 60

9.0 9.6 12

141414

15 20 20

30 30 30

7.2 7.7 9.6

141414

15 15 20

30 30 30

12.5 15 17.5

30 36 42

886

50 60 80

60 60100

15 18 21

141210

25 30 40

30 30 60

12 14 17

141412

20 25 30

30 30 30

20 22.5 25

48 54 60

644

80100100

100100100

24 27 30

10108

40 50 50

60 60 60

19 22 24

101010

35 40 40

60 60 60

30

35 40

72

84 96

3

21

125

150175

200

200200

36

42 48

8

66

60

80 80

60

100100

29

34 38

8

86

50

60 80

60

60100

45 50 60

108120144

1/02/03/0

200200250

200200400

54 60 72

442

100100125

100100200

43 48 58

664

90100100

100100100

75 80 90

180192216

250M300M350M

300350400

400400400

90 96108

1/01/01/0

150175200

200200200

72 77 86

331

125150150

200200200

100120125

241289300

400M(2)3/0(2)3/0

400500500

400600600

120144150

2/03/03/0

200200250

200200400

96115120

12/02/0

175200200

200200200

150180200

361432481

(2)250M(2)350M(2)400M

600750800

600800800

180216241

250M350M400M

300400400

400400400

144173192

3/0250M300M

250300350

400400400

240250300

———

———

———

———

289300361

(2)3/0(2)4/0(2)250M

500500600

600600600

231241289

400M400M(2)3/0

400400500

400400600

360400

——

——

——

——

432480

(2)350M(2)500M

750800

800800

346384

(2)250M(2)300M

600650

600800


15/64


35September 2011


Sheet 35

600 Volts AC and Below

General Description015

UNIPUMP Power FactorCorrection Capacitors

UNIPUMP

General DescriptionNon-fused capacitors for outdoorirrigation and oil field installations.

■ Designed expressly for outdoorpumping applications

■ Pole or wall mounting

■ Small, light-weight enclosurefor easy installation

■ SO-WA type flexible cablefacilitates installation (4-conductor)

■ Gland-type weatherproof bushings

■ Strong outer case

■ UL and CSA listed

Application Description

Outdoor irrigation and oil and gasfield pumping.

Features

Configuration■ Outer case: Heavy, No. 14 gauge

steel finished with durable baked-onenamel. Integral strap mountingbracket with keyhole at top for poleor wall installation. No knockouts

Capacitor Cells

■ Terminals: Insulated finger-safeterminals rated for 3 kVAC withstand

■ Dielectric fill: Cells use soft organicpolymer resin—Resinol

❑ Eliminates potential for corona/ partial discharge/electrochemicaloxidation

❑ Excellent heat dissipation

❑ Flash point: +444°F (+229°C)

❑ Fire point: +840°F (+449°C)

■ Design: Self-healing metallized highcrystalline polypropylene with rampmetallization film. Total losses lessthan 0.45 watt per kVAR. (Dielectriclosses less than 0.2 watt per kVAR)

■ Ramp metallization: Provides thickerfilm at higher current density areas,allowing for reduced internal losses,lower operating temperatures andlonger life expectancy. Also preventschain reaction breakdown by limitingpropagation of film vaporization

■ Pressure sensitive interrupter:Built-in UL recognized three-phasepressure-sensitive interrupter andthermally or mechanically activateddisconnecting link removes capaci-tor from the supply before danger-ous pressure buildup or excessivefault current. Bulged capacitor celltop provides easy visual indicationof interrupter operation

■ Ceramic discharge resistors: Reduceresidual voltage to less than 50Vwithin one minute of de-energiza-tion. Selected for 20-year nominallife. Exceeds NEC requirements

■ Capacitor operating temperature:–40° to +115°F (–40° to +46°C)

■ Case: Weatherproof aluminumhousing

■ Warranty: The longest in theindustry—five full years ofwarranty on capacitor cells

Product Selection

Table 35.1-1. UNIPUMP Selection Chart

kVAR RatedCurrent

CaseSize

CableSize

Shipping Weightin Lbs (kg)

CatalogNumber

240 Vac

2

2.5 3

4.8

6.0 7.2

AA

AAAA

14.0

14.014.0

10.0 (4.7)

10.0 (4.7)10.0 (4.7)

223JMR

2X23JMR323JMR

4 5 6 7.5

9.612.014.418.0

AAAABBBB

14.014.012.012.0

11.0 (4.8)11.0 (4.8)15.0 (6.6)15.0 (6.6)

423JMR523JMR623JMR7X23JMR

480 Vac

2 2.5 3

2.4 3.0 3.6

AAAAAA

14.014.014.0

10.4 (4.7)10.4 (4.7)10.4 (4.7)

243JMR2X43JMR343JMR

4 5 6

4.8 6.0 7.2

AAAAAA

14.014.014.0

10.4 (4.7)10.4 (4.7)10.6 (4.8)

443JMR543JMR643JMR

7.51012.5

9.012.015.0

AAAABB

14.014.012.0

10.6 (4.8)10.8 (4.9)15.0 (6.8)

7X43JMR1043JMR12X43JMR

1517.52025

18.021.024.030.0

BBBBBBBB

12.0 8.0 8.0 8.0

15.0 (6.8)15.8 (7.2)16.8 (7.7)16.8 (7.7)

1543JMR17X43JMR2043JMR2543JMR

600 Vac

5 6 7.5

4.9 5.9 7.4

AAAAAA

14.014.014.0

10.8 (4.9)10.8 (4.9)10.8 (4.9)

563JMR663JMR7X63JMR

1012.515

9.812.314.7

AABBBB

14.012.012.0

10.8 (4.9)15.0 (6.8)15.8 (7.2)

1063JMR12X63JMR1563JMR

17.520

17.219.6

BBBB

8.0 8.0

16.8 (7.7)16.8 (7.7)

17X63JMR2063JMR


16/64

5.1-2


September 2011


Sheet 35

2

3

4

5

6

7

8

9

0

1

2

3

4

5

6

7

8

9

0

1

2

3


Dimensions016

Dimensions

Figure 35.1-1. UNIPUMP—Dimensions in Inches (mm)

Table 35.1-2. UNIPUMP Dimension Chart

CaseSize

Dimensions in Inches (mm)

A B C D

AABB

11.00 (279.7)14.00 (354.5)

14.20 (360.9)17.10 (435.6)

12.60 (320.0)15.50 (394.7)

13.20 (335.5)16.10 (410.2)


17/64


35September 2011


Sheet 35



Low Voltage Power FactorCorrection Capacitor Banksand Harmonic Filters

Low Voltage Power Factor CorrectionCapacitor Banks and Harmonic Filters

General Description

Power Factor Correction CapacitorsEaton Power factor correctioncapacitors and harmonic filters arean essential part of modern electricpower systems. Power factorcorrection capacitors are the simplestand most economical means ofincreasing the capacity of any powersystem, minimizing energy lossesand correcting load power factor. Inaddition, power factor penalties canbe reduced and power quality can begreatly enhanced.

There are several reasons to correctpoor power factor. The first is toreduce or eliminate a power factorpenalty charged by the utility. Anotherreason is that your existing trans-former is, or shortly will be, at fullcapacity and installing power factorcorrection capacitors can be a verycost-effective solution to installing abrand new service. Depending on theamount of power factor correction(kVAR that needs to be injected intothe electrical system to improve thepower factor) and the dynamic natureof the load, a fixed or switched capaci-tor bank may be the best solution.

When capacity becomes a problem,the choice of a solution will be depen-dent upon the size of the increaseneeded. Like all power quality solu-tions, there are many factors that needto be considered when determiningwhich solution will be best to solveyour power factor problem.

Note: Images contained in this documentmay be shown with optional componentsand features not included as part of thebase offering.

Harmonic FilteringAs the world becomes moredependent on electric and electronicequipment, the likelihood that thenegative impact of harmonic distortionincreases dramatically. The efficiency

and productivity gains from theseincreasingly sophisticated piecesof equipment have a negative sideeffect…increased harmonic distortionin the power lines. The difficult thingabout harmonic distortion is determin-ing the cause. Once this has beendetermined, the solution can be easy.Passive and active harmonic filteringequipment will mitigate specificharmonic issues, and correct poorpower factor as well.

Features, Benefitsand Functions

■ Five-year warranty on capacitor cells

■ Designed for heavy-duty applications

■ Twenty-year life design

■ Indoor/outdoor service

■ Wall (up to 180 kVAR) and floor-mounted units available

■ Internally fused through the use ofan overpressure disconnector

■ Quick lead times

■ Harmonic filters available

■ Slim profile allows reduced footprint,conserving valuable floor space

■ New capacitor configuration leads

to cooler operating conditions andextended capacitor life

Configuration

■ Outer case: Heavy, No. 14 gaugesteel finished with durable baked-onenamel. Wall-mounting flanges andfloor-mounting feet. Elimination ofknockouts permits indoor/outdooruse. Manufactured to NEMArequirements 1, 3R and 12

■ Elevated floor-mounting feet allowaccess for easy maintenance

Note: NEMA 12 from enclosure sizes A1through C1.

■ Cover: “L” shaped gasketed coverwith multiple fasteners providesfront opening for ease of installationand service

■ Ground terminal: Furnishedinside case

■ Power terminal lugs: Large sizeprovided for easy connection

■ Options:

❑ Replaceable fuses andindicator lights

❑ Air filters for enclosure sizes C2and larger

■ Optional Fusing:

❑ Size Code A1: Three midget-typefuses with 100,000 ampere inter-rupting capacity

❑ Size Code A2 and larger: Slotted-blade type fuses with 200,000Ainterrupting capacity; fusesmounted on stand-off bushings;solderless connectors foreasy hookup of incoming lineconductors

❑ Fuse indicating lights: Red, neonblown-fuse indicating lights areprotected by transparent weather-proof guard

UNIPAK with Optional Air Filter

Standards and Certifications



18/64

5.1-4


September 2011


Sheet 35

2

3

4

5

6

7

8

9

0

1

2

3

4

5

6

7

8

9

0

1

2

3



UNIPAK

UNIPAK

UNIPAK Interior

UNIPAK with Optional Air Filter

General Description

UNIPAK Filter—Harmonic FilteringHarmonic filter systems for lowvoltage, heavy-duty applications.

■ Reduce harmonics and correctpower factor

■ Tuned for maximum efficiencyin reducing harmonic currentsassociated with nonlinear loadenvironments (such as VFDs)

■ Two-enclosure design isolatescapacitors from high-temperatureoperating reactors, and allows forflexible installation

■ Twenty-year life design

■ Five-year cell warranty/one-yearreactor warranty

■ Three-phase cell capacitor construc-tion. Three-phase interrupter system


Capacitor Cells

■ Terminals: Insulated finger-safeterminals rated for 3 kVAC withstand

■ Dielectric fill: Cells use soft organicpolymer resin—Resinol

❑ Eliminates potential for corona/ partial discharge/electrochemicaloxidation

❑ Excellent heat dissipation

❑ Flash point: +444°F (+229°C)

❑ Fire point: +840°F (+449°C)

■ Design: Self-healing metallized high

crystalline polypropylene with rampmetallization film. Total losses lessthan 0.45 watt per kVAR (dielectriclosses less than 0.2 watt per kVAR)

■ Ramp metallization: Providesthicker film at higher current densityareas, allowing for reduced internallosses, lower operating tempera-tures and longer life expectancy.Also prevents chain reactionbreakdown by limiting propagationof film vaporization

■ Pressure sensitive interrupter:Built-in UL recognized three-phasepressure-sensitive interrupter andthermally or mechanically activated

disconnecting link removes capaci-tor from the supply before danger-ous pressure buildup or excessivefault current. Bulged capacitor celltop provides easy visual indicationof interrupter operation

■ Ceramic discharge resistors: Reduceresidual voltage to less than 50Vwithin one minute of de-energiza-tion. Selected for 20-year nominallife. Exceeds NEC requirements

■ Capacitor operating temperature:

–40° to +115°F (–40° to +46°C)■ Case: Weatherproof aluminum

housing

■ Warranty: The longest in theindustry—five full years ofwarranty on capacitor cells

Harmonic rated capacitor cells

■ Standard voltage rated capacitorcells designed for higher dielectricstrength and with added ability towithstand stress caused by dv/dtvoltage transients caused byharmonics

■ Better suited for harmonic applica-tions than higher voltage rated cells

UNIPAK with harmonic ratedcapacitor cells

■ Standard capacitor systems usingharmonic rated capacitor cells

■ For use in moderate harmonicenvironments where engineeringsupervision allows in place ofharmonic filter designs

■ Provides future conversioncapability into a harmonic filterdesign due to facility growth orincreased nonlinear load levels

Reactors

■ Tuning: Tuned to 4.7 harmonic order■ Detuning: Reactor designs can be

detuned upon request (4.2nd, 6.7thfor example) to protect capacitorsagainst alternate harmonics

■ Construction: 100% copperwindings for cool operatingtemperatures; designed operatingtemperature rise less than 80ºC.Open frame construction with 220ºCinsulation system

■ Thermal sensors: One per phase,self-resetting thermistors providereactor over-temperature protectionand indication

■

Reactor indicating light: Thermaloverload indicating light activateswhen reactor temperaturereaches 180ºC

■ Warranty: One-year replacementof reactors


19/64


35September 2011


Sheet 35


Technical Data019

UNIPAK Low Voltage Fixed Capacitor BanksTable 35.1-3. 240 Vac UNIPAK Selection Chart

Notes:

■ Multiply the 240 Vac kVAR rating by 0.75 to calculate the kVARvalue at 208 Vac

■ Internally fused available standard. Replaceable fuses andindicator lights also available—please consult the factory

■ For dimensional information, refer to Pages 35.1-8 and 35.1-9

Part numbers for Tables 35.1-3 and 35.1-4:

■ PMURN—internally fused

■ PMURF—replaceable fuses and indicator lights

Table 35.1-4. 480 Vac UNIPAK Selection Chart

Notes:



kVAR RatedCurrent

Enclosure Shipping Weightin Lbs (kg)

CatalogNumber

1.0

1.5 2.0

2.4

3.6 4.8

A1

A1A1

18 (8)

18 (8) 19 (9)

123PMURN

1X23PMURN223PMURN

2.5 3.0 4.0

6.0 7.2 9.6

A1A1A1

19 (9) 19 (9) 20 (9)

2X23PMURN323PMURN423PMURN

5.0 6.0 7.5

12.0 14.4 18.0

A2A2A2

29 (13) 29 (13) 30 (14)

523PMURN623PMURN7X23PMURN

8.0 10.0 12.5

19.2 24.0 30.0

A2A2A2

31 (14) 31 (14) 32 (14)


15.0 17.5 20.0

36.0 42.0 48.0

A2B1B1

33 (15) 44 (20) 45 (20)

1523PMURN17X23PMURN2023PMURN

22.5 25.0 30.0

54.0 60.0 72.0

B1B1B1

46 (21) 46 (21) 47 (21)


32.5 35.0 37.5

78.0 84.0 90.0

B1B1C1

47 (22) 48 (22) 60 (27)

32X23PMURN3523PMURN37X23PMURN

40.0 42.5 45.0

96.0102.0108.0

C1C1C1

64 (29) 65 (30) 66 (30)


50.0 60.0 70.0

120.0144.0168.0

C1C1C2

68 (31) 69 (31) 99 (45)

5023PMURN6023PMURN7023PMURN

75.0 80.0 90.0

180.0192.0216.0

C2C2C2

100 (46)101 (46)103 (47)


100.0120.0140.0

240.0288.0336.0

C2D1D1

104 (47)133 (60)137 (62)


150.0160.0

180.0200.0

360.0384.0

432.0480.0

D1E1

E1E1

140 (64)175 (80)

182 (83)189 (86)

15023PMURN16023PMURN


kVAR RatedCurrent


CatalogNumber

1.5

2.0 2.5

1.8

2.4 3.0

A1

A1A1

17 (8)

18 (8) 18 (8)

1X43PMURN

243PMURN2X43PMURN

3.0 4.0 5.0

3.6 4.8 6.0

A1A1A1

19 (9) 19 (9) 19 (9)


6.0 7.5 8.0

7.2 9.0 9.6

A1A1A1

19 (9) 20 (9) 20 (9)


9.0 10.0 12.5

10.8 12.0 15.0

A1A1A2

20 (9) 20 (9) 29 (13)


15.0 17.5 20.0

18.0 21.0 24.0

A2A2A2

29 (13) 30 (14) 31 (14)


22.5 25.0 27.5

27.0 30.0 33.0

B1A2B1

44 (20) 32 (15) 44 (20)


30.0 32.5 35.0

36.0 39.0 42.0

B1B1B1

44 (20) 45 (20) 45 (20)


37.5 40.0 42.5

45.0 48.0 51.0

B1B1B1

46 (21) 46 (21) 47 (21)


45.0 50.0 55.0

54.0 60.0 66.0

B1B1B1

47 (22) 48 (22) 48 (22)


60.0 65.0 70.0

72.0 78.0 84.0

B1C1C1

48 (22) 64 (29) 65 (30)


75.0 80.0 85.0

90.0 96.0102.0

C1C1C1

65 (30) 66 (30) 68 (31)


90.0100.0

120.0

108.0120.0

144.0

C1C1

C1

68 (31) 69 (31)

69 (31)

9043PMURN10043PMURN

12043PMURN125.0140.0150.0

150.0168.0180.0

C2C2C2

99 (45)100 (46)101 (46)


160.0180.0200.0

192.0216.0240.0

C2C2D1

103 (47)104 (47)137 (62)


225.0250.0300.0

270.0300.0360.0

D1E1E1

140 (64)170 (77)175 (80)


350.0400.0

420.0480.0

E1E1

182 (83)189 (86)



20/64

5.1-6


September 2011


Sheet 35

2

3

4

5

6

7

8

9

0

1

2

3

4

5

6

7

8

9

0

1

2

3


Technical Data020

UNIPAK Low Voltage Fixed Capacitor BanksTable 35.1-5. 600 Vac UNIPAK Selection Chart

Notes:



Part numbers

■ PMURN—internally fused

■ PMURF—replaceable fuses and indicator lights

UNIPAK—With Harmonic CellsTable 35.1-6. Low Voltage Fixed Capacitor Systems with Harmonic Cells

kVAR RatedCurrent


CatalogNumber

5.0

7.5 10.0

4.9

7.4 9.8

A1

A1A1

19 (9)

19 (9) 20 (9)

563PMURN

7X63PMURN1063PMURN

12.5 15.0 17.5

12.3 14.7 17.2

A1A2A2

20 (9) 29 (13) 29 (13)


20.0 22.5 25.0

19.6 22.1 24.5

A2B1B1

30 (14) 44 (20) 31 (14)


27.5 30.0 32.5

27.0 29.4 31.9

B1B1B1

44 (20) 45 (20) 45 (20)


35.0 37.5 40.0

34.3 36.8 39.2

B1B1B1

46 (21) 46 (21) 47 (21)


42.5 45.0 50.0

41.7 44.1 49.0

B1B1B1

47 (22) 48 (22) 48 (22)


55.0 60.0 65.0

53.9 58.8 63.7

C1C1C1

64 (29) 64 (29) 65 (30)


70.0 75.0 80.0

68.6 73.5 78.4

C1C1C1

65 (30) 66 (30) 68 (31)


85.0 90.0100.0

83.3 88.2 98.0

C1C1C1

68 (31) 69 (31) 69 (31)


120.0125.0140.0

117.6122.5137.2

C2C2C2

99 (45)100 (46)101 (46)


150.0160.0180.0

147.0156.8176.4

C2D1D1

103 (47)135 (61)137 (62)


200.0225.0

250.0

196.0220.5

245.0

D1D1

E1

140 (64)143 (65)

170 (77)


25063PMURN300.0350.0400.0

294.0343.0392.0

E1E1E1

175 (80)182 (83)189 (86)


kVAR RatedCurrent

CaseSize


CatalogNumber

240V

15 25 30

36.0 60.0 72.0

B1B1C1

38.4 (17) 38.4 (17) 55.2 (25)

1523HURN2523HURN3023HURN

50 60 75

120.0144.0180.0

C1C2C2

57.6 (26)100.8 (46)104.4 (47)


100125

240.0300.0

D1E1

136.8 (62)189.6 (86)

10023HURN12523HURN

480V

15 25 30

18.0 30.0 36.0

A2B1B1

25.2 (11) 37.2 (17) 38.4 (17)


50 60 75

60.0 72.0 90.0

B1C1C1

39.6 (18) 52.8 (24) 55.2 (25)


100125

150

120.0150.0

180.0

C1C2

C2

57.6 (26)100.8 (46)

104.4 (47)

10043HURN12543HURN

15043HURN200250300

240.0300.0360.0

D1E1E1

136.8 (62)186.0 (84)189.6 (86)


600V

15 25 30

14.7 24.5 29.4

B1B1B1

37.2 (17) 38.4 (17) 39.6 (18)


50 60 75

49.0 58.8 73.5

C1C1C2

55.2 (25) 57.6 (26)100.8 (46)


100125150

98.0122.5147.0

C2D1D1

104.4 (47)136.8 (62)136.8 (62)


200250

196.0245.0

E1E1

186.0 (84)189.6 (86)

20063HURN25063HURN


21/64


35September 2011


Sheet 35


Technical Data021

UNIPAK Low Voltage Fixed Harmonic FiltersTable 35.1-7. Fixed UNIPAK Harmonic Filters

Note: Other ratings available, please consult factory.

Figure 35.1-2. Reactor Cabinet

Table 35.1-8. Reactor Cabinet—Dimensions in Inches (mm)

Figure 35.1-3. Filter Schematic with Wiring Interconnects Refer to NEC.

kVAR RatedCurrent

CaseSize


Reactor CabinetCase Size

Reactor ShippingWeight in Lbs (kg)

Combined ShippingWeight in Lbs (kg)

CatalogNumber

240V

15 25 30

36.0 60.0 72.0

B1B1C1

48.4 (22.0) 48.4 (22.0) 65.2 (29.6)

RRR

90.0 (40.9)105.0 (47.7)110.0 (49.9)

138.4 (62.8)153.4 (69.6)175.2 (79.5)

15232HMURF25232HMURF30232HMURF

50 60 75

120.0144.0180.0

C1C2C2

67.6 (30.7)110.8 (50.3)114.4 (51.9)

RRR

130.0 (59.0)160.0 (72.6)185.0 (84.0)

197.6 (89.7)270.8 (122.9)299.4 (135.9)


100125150

240.0300.0360.0

D1E1E1

146.8 (66.6)199.6 (90.6)220.0 (99.9)

RSS

240.0 (109.0)280.0 (127.1)280.0 (127.1)

386.8 (175.6)479.6 (217.7)500.0 (227.0)


480V

15 25 30

18.0 30.0 36.0

A2B1B1

35.2 (16.0) 47.2 (21.4) 48.4 (22.0)

RRR

90.0 (40.9)105.0 (47.7)110.0 (49.9)

125.2 (56.8)152.2 (69.1)158.4 (71.9)


50 60 75

60.0 72.0 90.0

B1C1C1

49.6 (22.5) 62.8 (28.5) 65.2 (29.6)

RRR

130.0 (59.0)160.0 (72.6)185.0 (84.0)

179.6 (81.5)222.8 (101.2)250.2 (113.6)


100

125150

120.0

150.0180.0

C1

C2C2

67.6 (30.7)

110.8 (50.3)114.4 (51.9)

R

RS

240.0 (109.0)

280.0 (127.1)280.0 (127.1)

307.6 (139.7)

390.8 (177.4)394.4 (179.1)

100432HMURF

125432HMURF150432HMURF

200250300

240.0300.0360.0

D1E1E1

146.8 (66.6)196.0 (89.0)199.6 (90.6)

STT

330.0 (149.8)570.0 (258.8)575.0 (261.1)

476.8 (216.5)766.0 (347.8)774.6 (351.7)


600V

15 25 30

14.7 24.5 29.4

B1B1B1

47.2 (21).4 48.4 (22.0) 49.6 (22.5)

RRR

90.0 (40.9) 90.0 (47.7)105.0 (49.9)

137.2 (62.3)153.4 (69.6)159.6 (72.5)


50 60 75

49.0 58.8 73.5

C1C1C2

65.2 (29.6) 67.6 (30.7)110.8 (50.3)

RRR

110.0 (59.0)130.0 (72.6)160.0 (84.0)

195.2 (88.6)227.6 (103.3)295.8 (134.3)


100125150

98.0122.5147.0

C2D1D1

114.4 (51.9)146.8 (66.6)146.8 (66.6)

RSS

185.0 (109.0)240.0 (127.1)280.0 (127.1)

354.4 (160.9)426.8 (193.

Documents

Eaton - Compensare