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INSTALLATION AND MAINTENANCEMANUAL FOR EBARA STANDARD
cNON-SUBMERSIBLE PUMPSv
GEN-SM2-0305
c-1 Checks Prior to Operation 11c-2 Operational Procedure 13c-3 Checks During Operation 13
1. INSTALLATION PLANNING 1
CONTENTS
2. INSTALLATION 7
3. TEST OPERATION 11
v-1 Daily Maintenance 16
v-2 Overhaul 17
v-3 Cautions During Non-operation 17
4. MAINTENANCE 16
z-1 Suction lift 1z-2 Pump Location 2z-3 Suction Pipe 3z-4 In-line Pump 5z-5 Self-priming Pump 6
x-1 Centering The Coupling 7q Importance of centering 7w Centering adjustment at the worksite 7e Tolerances for direct coupling centering 8r Direct coupling centering 8
x-2 Piping 9q Suction pipe 9w Discharge pipe 10e Connection between pump and pipeline 10
5. GLAND PACKING AND MECHANICAL SEAL 18
6. MALFUNCTIONS, POSSIBLE CAUSES AND REMEDIES 26
7. ELECTRICAL INSPECTION 31
b-1 Gland Packing 18q Function of gland packing 18w Proper leakage 18e Adjustment 18r Replacement 19
b-2 Mechanical Seal 21q Function 21w Cautions for operation 21e Replacement (Model LPD Line Pump) 22
11. INSTALLATION PLANNING
z-1 SUCTION LIFT (General Information)Suction lift will be changed according to pump characteristics, type and temperature of the liquid handled
and piping conditions. When preparing a plan for installation, the following should be taken into
consideration.
qNormal temperature, fresh waterHeight from suction-water level to pump center-within 6m
(Depend on various conditions)
wHigh water temperatureSuction lift decrease according to temperature.
eLong suction pipeA long suction pipe reduces suction lift due to the increase in pipeline resistance.
rHandling of various liquidsCertain chemicals and coal oils are highly volatile and, when handled, the pump may require a flooded
suction system.
Water temperature Suction lift
20: -6m40 -560 -370 -280 0
100 +7
Suction limits
flooded suction is
required
Fig. 1-1 Fig. 1-2
2 1. INSTALLATION PLANNING
z-2 PUMP LOCATIONqDry location
Installing a pump at a location with high humidity will cause the bearings to rust and/or motor insulation
resistance to decrease, which can shorten the life of the motor.
wAmbient temperature under 40:When ambient temperature is high, increase in motor temperature, decrease in insulation resistance, etc.
;can occur. It is advisable, therefore to install the pump not only in a well-ventilated location but also as
far as possible from a high temperature unit, such as a boiler.
eAllow sufficient space for disassembly and inspectionSmall pump room makes pump inspection and disassembly difficult, resulting in undue consumption of
time. Too, even daily maintenance is apt to be neglected, which will, of course, affect the life of the
pump. Be sure to allow enough space above as well as around the pump.
rIndoor installationMotor usually designed for indoor use. If the motor is to be installed outdoors, it must be provided with a
protective covering against rain. When a motor is installed outdoors without covering, insulation
resistance will decrease or the pump may rust, either of which can be to unexpected accidents.
tVibration absorbing base and flexible jointsUse of a vibration absorbing base that reduces vibration.
When selecting a vibration absorbing base, it is recommended the matter be discussed with a
construction engineer. Make sure the supports are provided with rubber packing, as shown in the
following. (See Fig.1-3)
31. INSTALLATION PLANNING
z-3 SUCTION PIPEImproper installation of the suction pipe may be result in failure to pumping. Care should be taken with the
following:
qPiping should have minimum length and bends.It is recommended that the length of the pipe and the number of bends be minimized. Moreover, it should
be considered that the connections pipe will be greater the possibility of air intrusion.
Fig. 1-3
Fig. 1-4 Fig. 1-5
4 1. INSTALLATION PLANNING
wEnsure piping contains no convex areas which cause airpockets
Should there be a convex area in the suction pipe, when the
pump is primed, air will remain in this area. When the pump is
started, air will be drawn into the pump, and the pump will not
operate.
ePiping layout which facilitates easy removal of suctionpiping
One cause can be a foot valve leak. It the suction pipe can be
easily lifted, inspection and repair can be quickly and efficiently
accomplished.
When planning, it is recommended that use of an EBARA
suction unit be considered.
MSuction UnitThe EBARA suction unit will be used for simplifies pipe
inspection from the foot valve to the suction port.
¡Advantages
1. The suction pipe can be installed after finishing thefloor surface.
2. Lever control of the foot valve may be easilyaccomplished at pump level.
3. Both foot valve and suction pipe can be inspected atpump level when the foot valve is lifted together with
the suction pipe, eliminating the need of entering the
pit.
Fig. 1-6
Fig. 1-7
Fig. 1-8
51. INSTALLATION PLANNING
z-4 IN-LINE PUMPWhen planning installation of in-line type pump, care should be taken with the following.
qDo not install in convex portion of pipingShould the pump be installed in a convex portion, that is, in an air pocket of the piping system, it will
operate in a dry condition, causing damage to the shaft seal.
wInstall the pump with motor on top or any sideThis type of pump must be installed according to Fig.1-10.
eValves on both sides of the pumpWhen the pump is used for a circulating system (cooling, cold/hot water circulation, etc.), install valves
on both discharge and suction sides.
If this is not done, the water in the pipeline must be drained when removing or disassembling the pump.
Fig. 1-9
Fig. 1-10
Fig. 1-11
6 1. INSTALLATION PLANNING
z-5 SELF-PRIMING PUMPAir vent valve
An air vent valve must be installed between the valve and the pump discharge port so as to release the air
exhausted during self-priming action. Without this air vent valve, the pump cannot complete its self-priming
function.
(Model SQ) (Models MSQ)
Fig. 1-12 Fig. 1-13
72. INSTALLATION
x-1 CENTERING THE COUPLINGqImportance of centering
When pump and motor are direct coupled, shaft alignment is of primary importance. Alignment is usually
checked at circumference of coupling.
¡When centering of the coupling is not satisfactory:1) Vibration or noise is made
2) Coupling rubber is subject to abnormal wear
3) Gland packing is subject to abnormal wear
4) Bearings wear prematurely
80 per cent of the trouble arising from vibration and/or noise.
wCentering adjustment at the worksiteIf the pump is placed directly on the datum level and the anchor bolts are tightened, or if liners are
improper, even the iron base can be distorted and cause misalignment.
Fig. 2-1 Fig. 2-2 Fig. 2-3
8 2. INSTALLATION
eTolerances for direct coupling centering
Remove all paint on the coupling surface before measuring the centering of the coupling circumference.
rDirect coupling centeringWhen installing the pump, liners are placed between the foundation and the common base to form a
clearance for mortar. Direct coupling centering is made by adjusting the thickness of these liners.
1) Liners
A minimum number of thick liners should be used in stacks.
Use of tapered liners permits fine adjustment.
2) Location of liners
Liners should be placed on both sides of each anchor bolt
and under the base to prevent distortion. (See Fig2-7.)
Example: If A=2.87mm and B=2.81mm,
A-B=2.87-2.81=0.06(mm)/Satisfactory
1) Coupling circumference
difference
2) Coupling surface difference
Fig. 2-4 Fig. 2-5
Fig. 2-7
Fig. 2-6
92. INSTALLATION
3) Placing of liners
One of two flat liners and one tapered liner should
be used according to the clearance between the
common base can be raised by driving in a
tapered liner. (Refer to Fig.2-8.)
Large or heavy pumps should be installed as
shown in Fig.2-9. Even for a small pump, this
method permits ideal installation.
4) Direct coupling centering
Centering will not be exceed tolerable value.
x-2 PIPINGqSuction pipe
1) Air pocket prevention
The suction pipe should be installed with an
upward inclination of not less than 1/100 toward the
suction port of pump.
Should this method be impractical, an air vent valve
must be installed air to escape during priming. (See
Fig.2-12.)
If the height of the suction pipe is greater than the
position of the priming funnel, an air vent valve and
funnel should be installed in this area to facilitate
priming. (See Fig.2-13.)
Fig. 2-8
Fig. 2-9
Fig. 2-10
Fig. 2-11
Fig. 2-12 Fig. 2-13
10 2. INSTALLATION
2) Seal connections completely.
If flange seals or threaded couplings are not fix comptelely, water can not be pumped because of air
intrusion.
wDischarge pipeTo avoid excess pipe weight on the pump, supports should be
installed on all piping.
eConnection between pump and pipeline1) Ensure center of the pump flange is aligned with pipe
center.
2) After pipe installation, recheck the direct coupling center; If it
has changed, piping should be corrected.
3) The pump is shipped with suction and discharge ports
plugged. Ensure that caps are removed before attaching
pipes.
Also ensure that the pipes do not contain waste, wood or
foreign matter during installation.
Fig. 2-14
Fig. 2-15
Fig. 2-16
Fig. 2-17
113. TEST OPERATION
c-1 CHECKS PRIOR TO OPERATIONqWater tank interior
Ensure that water tank has been thoroughly cleaned. If there are bits of waste or wood, vinyl, concrete,
paper, etc., in the tank, they will clog the foot valves or impellers.
Make sure there is sufficient water in the tank. When the foot valve is not fully submerged (depth at least
twice the pipe size), air may enter the pump.
wBearing oil (Model MS pump)Apply lubricant (#140 turbine or equivalent) to pump having sleeve bearings. Since lubricant is removed
from bearings housing at prior to shipment from the factory.
eGrand packingEnsure that the gland packing is satisfactory. Check gland nuts for proper condition.
rRotating motor manuallyRotate the coupling, by hand. In case ot model LPD, insert a screwdriver in the groove on motor shaft
and manually rotate the pump. If the pump can not be turned easily, or the internal components contact
the casing,such distortion may be a result of excessive tightening of the gland packing or excessive pipe
loading.
tMotor protectorCheck that capacity of the motor protector is sufficient for the motor. Determine that voltage, phase and
frequency meet with the operating conditions listed on nameplate of the motor.
Do not attempt test operation using a temporary power source.
Direction
12 3. TEST OPERATION
yDirection of motor rotation1) Direct coupling pump (using couplings)
Remove the coupling bolts, operate the motor independently, and
check direction of rotation. (For a general-purpose pump, correct
rotation is clockwise when viewed from the driving end.)
Connection between power source and motor cable (Three-phase motor)
¡Single-phase motor will rotate in only one direction, it will notoperate in reverse.
2) Close coupled pump (no coupling)
Check the motor rotation. To reverse rotation, refer to the preceding
paragraph(1).
Fig. 3-2
Fig. 3-1
Rotation direction
133. TEST OPERATION
c-2 OPERATIONAL PROCEDUREqValves
If the suction side is provided with a valve, open it fully. Close the valve on the discharge side fully. (For
Models RS, RQ, RQD, GP, and GPA pumps, the valves on the discharge sides must be fully open.)
wPrimingFeed water to the pump and suction pipe by opening the funnel and air vent cocks.
When water spouts from the air vent cock, priming is completed.
For self-priming pumps, (Models SQ, MSQ or RQ), merely fill the pump with water. Air in the suction pipe
will be purged by self-priming action.
eIntermittent operationTurn the switch on and off two or three times, and while the pump is rotating check for possible abnormal
noise and/or vibration. Should malfunctions be detected, recheck direct coupling centering, rotation
direction and take remedial action. For a close coupled pump, check rotation direction at this time.
Should the pump be operating in reverse, make corrections as advised in Paragraph 6,3-1.
rContinuous operationAfter intermittent operation is performed, no abnormality is found, the pump may be operated
continuously.
c-3 CHECKS DURING OPERATIONqHead
Pump started with discharge valve fully closed then open discharge valve slowly.
Observing the gauges on both discharge and suction side, and adjust valve on the discharge side.
14 3. TEST OPERATION
Head can be obtained from gauge readings as follows:
Example 1
Discharge side gauge reading . . . . . . . .12m
Suction side gauge reading . . . . . . . . . . .-4m
Head=12-(-4)+=16.2(m)
Example 2
Discharge side gauge reading . . . . . . . .12m
Suction side gauge reading . . . . . . . . . . . .4m
Height difference of stations . . . . . . . . . .0.2m
Head=12-4+0.2=8.2(m)
¡Do not operate the pump for a long period with the discharge valvefully closed, due to the rise of water temperature in the pump will
generate heat, sometimes causing seizure.
wElectric currentObserve the control panel ammeter to ensure the current is within the rated value for the motor, as
described on the motor nameplate.
eWater volumeIt is difficult to measure the volume of water unless a flow meter is installed. Nevertheless, the amount of
water discharged can be estimated from the pump characteristic curve.
Fig. 3-3
Fig. 3-4
Fig. 3-5
153. TEST OPERATION
rGland packing leakageDetermine that the amount of water leakage at gland packing is proper. If there is no leakage, the
packing is burned. (See Fig.5-2, page 18.)
¡For adjustment and replacement of gland packing, see "Gland packing," page 18.
¡In the event air is drawn into the pump through the gland, the following causes may be considered.(1) Clogging of sealing port or pipe
The pump has been operated for a prolonged period of time, sealing port or pipe may clog with rust.
tVibrationIf installation and piping are proper, vibration is usually below 30 microns (at single amplitude). When
vibration is excessive, check direct coupling centering, faulty piping, loose anchor bolts, etc., and take
remedial measures.
16 4. MAINTENANCE
v-1 DAILY MAINTENANCEqChecks on operating condition
If head, electric current, temperature, vibration, noise, etc. are obviously different from those prescribed
for normal operation, something is wrong and corrective action.
wReplacement of expendables1) Gland packing
When gland packing leak becomes excessive, packing should be replaced.
2) Mechanical seal
If there is a leak in the mechanical seal, it should be replaced.
3) Coupling rubber
Coupling rubber should be replaced immediately when excessive vibration and/or noise are detected.
174. MAINTENANCE
eBall bearingsGenerally, bearings should be replaced every two or three years. However, if the pump is installed in an
area with excessive humidity or high ambient temperature, the grease will leak and rusted bearings
which will curtail service life. If this occurs, the bearings should be replaced immediately.
rLubricationModel MS pumps use sleeve metal and #140 turbine oil or its
equivalent as lubricant. In a new pump, oil should be changed
about once a week during initial stages of operation, and about
once every six months thereafter.
v-2 OVERHAULAfter several years, the moving parts in the pump wear and the water passages may become narrow due
to collected rust, resulting in deterioration of performance. The pump should be overhauled once every
three to five years to assure stable service for a long period of time.
v-3 SHUTDOWN CAUTIONSWhen a pump is to be taken out of service for an extended period, or, in a cold area for even a short time,
drain all water from the pump by opening the drain cock or plug.
Fig. 4-1
18 5. GLAND PACKING AND MECHANICAL SEAL
b-1 GLAND PACKINGqFunction of gland packing
The gland packing is not only minimizes leakage where the shaft passes through the casing; it also
prevents the intrusion of air.
The small leakage from gland area has the following three objectives:
(1) Lubricant between gland packing and shaft or
sleeve.
(2) Removal of friction-generated heat between
the packing and shaft or sleeve.
(3) Prevention of air intrusion at gland area.
wProper leakageA certain amount of water must continuously drip from the gland
area.
eAdjustment(1) Stop the pump and release internal pressure.
Ensure all internal pressure is released before adjusting
gland packing.
(2) Do not tighten too much at one time.
The gland packing is adjusted by the two gland nuts. The
gland is pushed in by tightening these nuts, thus compressing
the packing. The tightening limit is one turn of the nut. After
one adjustment, the pump should be operated for 10 to 15
minutes disregarding any leakage.
Fig. 5-1
Fig. 5-2
Fig. 5-3
195. GLAND PACKING AND MECHANICAL SEAL
(3) Manually rotate the pump.
After packing adjustment, rotate the pump by hand to secure a proper fit. If manual rotation is difficult,
the packing may be too tight.
Readjustment. Be careful not to tighten the packing too much.
rReplacement(1) Packing removal
Release internal pressure of the pump before removing the packing. A packing tool (with a
corkscrew), will facilitate this operation.
Insert the corkscrew into the packing and remove. Be careful not to scratch the shaft or sleeve.
(2) Stuffing box cleaning
All old packing must be removed from the stuffing box. Should the shaft or sleeve be scratched.
When diameters wear more than 1mm, replacement should be made.
Fig. 5-4 Fig. 5-4
20 5. GLAND PACKING AND MECHANICAL SEAL
(3) Packing preparation
Gland packing used for EBARA standard pumps is cut to
the desired length so that it may be formed into rings. This
packing is available at all EBARA dealers.
(See Fig.5-6)
When using long-size commercial packing, cut it as follows:
Example 1
Prepare a round bar with the same diameter as the shaft, wind
packing around the bar and cut it.
Example 2
Make a packing ring and determine the correct size by inserting it
into the stuffing box. Be sure the ring is cut at a 45°angle.
(4) Inserting packing
Application of a lubricant, such as molybdenum disulfide
(commercial brand: Molycoat), to the inner diameter of the
packing, will facilitate insertion.
When placing packing on the shaft, open the cross section
while twisting. If it is opened straight, there is a possibility
of breaking on the opposite side.
Push the packing rings into the stuffing box, one by one
staggering their cross sections by 180°.The gland in the
stuffing box and tighten nuts.
Fig. 5-6
Fig. 5-8
Fig. 5-9
Fig. 5-7
215. GLAND PACKING AND MECHANICAL SEAL
b-2 MECHANICAL SEALqFunction
Whereas a gland packing permits water lekage, the mechanical seal eliminates leakage where the shaft
passes through the casing.
The following figure shows an example of mechanical seal structure. The mechanical seal consists of
floating seat rotating together with the shaft and a seal ring fixed in a chamber.
While the pump is operating, water is forced against the seal, and forms a thin film of lubrication on the
seal surface.
If sand or rust cuts the seal surface, the seal will become unbalanced and cause leakage.
wCautions for operation(1) Do not allow an air pocket form in the pump or pipe.
Also it is important to completely exhaust the air in both, pump and pipe before beginning operation.
(2) Flush pipe fully.
Carefully clean piping and water storage areas to preclude rust, sand, pipe welding scraps, etc. from
entering the pump.
(3) Do not touch seal surface.
Do not touch the mechanical seal with gloved or dirty hands. Particularly careful not to touch the seal
surface at all.
(4) Be sure to clean the chamber and shaft.
Remove all rust, dirt and scratches from both chamber and shaft.
Fig. 5-10
22 5. GLAND PACKING AND MECHANICAL SEAL
eReplacement (Model LPD Line Pump)
Procedure Sketch
1. Turn off power
2. Close both discharge and suction valves.
1. Before disassembly place reference marks
on the casing and bracket, and the motor to
facilitate reassembly.
2. Remove clamp bolts from both casing and
bracket: separate the motor from the casing.
The motor can be removed with the impeller
attached.
Preparation
Disassembly
3. Straighten the bent portion of the impeller
nut washer: remove the impeller nut and
washer; remove the impeller.
235. GLAND PACKING AND MECHANICAL SEAL
Procedure Sketch
6. Push out the fixed side of the mechanical
seal incorporated in the bracket with a
screwdriver shown in the figure at right.
Should the rubber packing remain in the
bracket, remove by hand.
4. Remove the impeller key before removing
the slinger and rotating portion of the
mechanical seal.
When the rotating portion is difficult to
remove, remove it at the same time the
bracket is removed, as described in the next
phase of disassembly.
5. Remove the bracket clamping bolts and
separate the motor from the bracket.
Even when the rotating portion of the
mechanical seal remains attached to the
shaft, it can be pulled from the shaft by
removing the bracket.
24 5. GLAND PACKING AND MECHANICAL SEAL
Assembly
Essentially, assembly is accomplished by reversing the disassembly procedure.
Cautions and instructions:
(1) Cleaning mechanical seal chamber
Remove all rust and stains from the interior of the bracket.
(2) Installing seal ring
Insert the seal ring in the bracket with a lubricant, such as soapy water or molybdenum disulfide.
(3) Installing bracket
Attach the bracket to the motor making sure to align the reference marks made prior to disassembly.
The clamping bolts (four) should be tightened evenly and alternately.
(4) Installing floating seat
Fit the rotating portion of the mechanical seal to the shaft.
(5) Installing slinger
When installing the slinger align the notch with the tongue of the mechanical seal (directly above the
key way of the shaft).
Fig. 5-11
Fig. 5-12
255. GLAND PACKING AND MECHANICAL SEAL
(6) Installing impeller
Install the impeller, insert the washer and tighten with the impeller nut. The washer should be bent to
prevent rotation of the impeller nut.
(7) Assembling motor and pump casing
Attach the motor, with the impeller installed, to the casing.
26 6. MALFUNCTIONS, POSSIBLE CAUSES AND REMEDIES
MMajor malfunctionsqVibration and noise
wExcessive leakage at gland packing or mechanical seal
eMotor fails to start.
rPump fails to function.
tInsufficient water and pressure.
yOvercurrent
Intrusion of air fromgland packing.(See page 18.)
Pump fails to function
Check rotation direction. (See page 12.)
Proper rotation. Reverse rotation
Check primingThree-phase motor:Interchange two-phases (See page 12.)Single-phase motor: Motor is abnormal.
Priming not possible. Normal priming.
• Foot valve leak.• Suction pipe leak.
Check shut-off pressure.(See page 14.)
Normal shut-off pressure. Low.
Open discharge valve slowly.Insufficient exhaust of air.(See page 15.) Worm pump impeller, casing ring, etc.
Almost the same pressure as shut-off pressure. Sudden decrease in discharge pressure.
Check gauge readings on suction side.
-6m or more -6m max.
- Equipment head is too high. Suction head too high.(See page 1.)
Impeller or casing clogged.
Discharge valve or check valve will not open.
Suction piping system or foot valve clogged.
Excessice saturated vapor pressure. (See page 1.)
Clogging of dischargepiping. (See page 10.)
Lowering of suction water level.
Air pocket in discharge piping.
Excessive resistance in suction pipe. (See page 1.)
Air pocket in suctionpiping. (See page 9.)
Intrusion of air fromsuction pipe. (See page 9.)
276. MALFUNCTIONS, POSSIBLE CAUSES AND REMEDIES
Wrong pump selection.
Pump fails to start:
Rotate pump manually. (See page 12.)
Light load. Heavy load.
Assure motor protector in control panel is operating.(See page 33.)
Remove coupling bolts and manually rotate pump and motor independently.
Not operating. Operating. Manual rotation ofpump is difficult.
Manual rotation of motor is difficult.
Operate pump by turning on "automatic/manual selector" switch manually.
Restore the protective device to its original position and restart. (See page 33.)
Moving parts of motor restrained. Disassemble motor and repair or replace.
Fails to start.Protector operates themoment switched on.
Pro
tect
ive
devi
ceop
erat
es a
fter
seve
ral s
econ
ds.
Damaged bearing.Bent shaft and contact of rotating parts.
Will start.Protective device occasionally operates.
Excessive tightening of gland packing. (See page 18.)
Intrusion of foreign matter.
Ensure magnetic contactor is on.
Adjust or replace packing gland.
Disassemble; replacedefective parts.
Defective automaticcontrol equipment (liquid surface relay,float switch, pressure switch, etc.).
Remove motor cable from control panel andmeasure voltage by use of terminals U,V,W. (See page 33.)
Check current duringoperation.(See page 14.)
Disassemble and remove foreign matter.
Magnetic contactoris on.
Magnetic contactor not on.
Normal.
Normal.
Normal.Abnormal.
Abnormal. Normal. Normal.Abnormal. Abnormal.
Abnormal.
Measure voltage using motor cable terminals U,V,W. at control panel.(See page 33.)
Check power voltage (R.S.T.).(See page 33.)
Measure motor insulation and conductor resistance. (See page 31.)
Abnormal panel or power source.
Check that set value of protectormatch with motor rating. (See page 33.)
Inspection made by competent electrician.
Match. Does not match.
Defective cable between control panel and motor or malfunction of automatic motor protector.
Trouble on power side.Replace defective motor.
Protector is defective.Replace.
Defective parts in control panel.
Overload due to excessive water or too high specific gravity of liquid.
Correct setting.
Replace motor or cable. Inspection made by competent electrician.
Inspection made by competent electrician.
28 6. MALFUNCTIONS, POSSIBLE CAUSES AND REMEDIES
Insufficient water and pressure:
Check rotation direclion.(See page 12.)
Proper rotation. Reverse rotation.
Check shut-off pressure with discharge valve fully closed.(See page 14.)
Three-phase motor: Interchange two-phases.Single phase Motor:Motor is abnormal. (See page 12.)
Normal shut-off pressure. Insufficient.
Fully open discharge valve. Insufficient air exhaustion. Worn pump interior.
Compare pump specifications with gauge readings duringoperation. (See page 14.)
Operating head higher than specified.
Operating head lower than specified.
Check gauge reading on suction side.
Equipment head too high. -6m or more. -6m max.
Excessive suction head. (See page 1.)
Foreign matter in suction pipe.(See page 11.)
Lowering of suction water level.
Excessive resistance of suction pipe.(See page 1.)
Foreign matter in impeller or casing.
Excessive saturated vaporpressure. (See page 1.)
296. MALFUNCTIONS, POSSIBLE CAUSES AND REMEDIES
Intrusion of foreign matter.
Overcurrent:
Check rotation direction. (See page 12.)
Proper rotation. Reverse rotation.
Measure current with discharge valve fully closed. (See page 14.)
Three-phase motor:Interchange two-phases Single phase motor.Motor is abnormal.(See page 12.)
Normal. Abnormal.
Excessive water. Rotate manually. Specific gravity of liquid too high.
Adjust discharge valve so that current match with the rating.
For other steps, see "Pump fails to start."
Excessive leak at gland packing.
Tighten packing more securely. (See page 18.)
Excessive leak in spite of retightening.
Sleeve or shaft wear.Packing wear due to presence of slurry.
Pressure too high. Worn out packing.
Excessive leakage at mechanical seal.
Pressure too high.Crack in hardened rubber area.
Abnormal wear of seal surface.
Worn out mechanical seal.
Dry operation.
30 6. MALFUNCTIONS, POSSIBLE CAUSES AND REMEDIES
Bearing damage.
Vibration/Noise:
Check rotation direction. (See page 12.)
Proper rotation. Reverse rotation.
Check direct coupling centering. (See page 6.)
Three-phase motor: Interchange two-phases.Single phase motor: Motor is abnormal.(See page 12.)
Satisfactory. Defective.
Location of vibration or noise.
Replace coupling rubberand bolts.
Bearings. Pump interior. Room interior, foundation and piping.
Bearing corrosion.
Check vacuum on suction side.
Water hammer.
Worn out bearing. Resonance of pipeline or foundation.
-6m or more -6m max.
Cavitation.Foreign matter in pump or contact rotating parts.
317. ELECTRICAL INSPECTION
m-1 CHECKING MOTOR FOR INSULATION AND CONDUCTOR RESISTANCEMeasurement of insulation resistance
Measuring instrument: Resistance tester (500V cap.)
Measured values Shown as follows
...Standards of judgement
Cautions during measurement (ensure power supply has cut off)
(1) Disconnect cable from motor terminals before measuring
insulation resistance of motor. If measurement is made
with the cable connected.
Fig. 7-1
Fig. 7-2
32 7. ELECTRICAL INSPECTION
(2) Consideration of measured values
1)Example
Pump 1 pump 2
Oct. 1 5MΩ 10MΩNov. 1 5MΩ 5MΩ
On Nov. 1, the measured values of both pumps were 5MΩ, the values of Pump 1 did no change
(5MΩ/5MΩ), but Pump 2 was changed (10MΩ/5MΩ). Remedial measures must be takenresistance falls.
2) When a motor fails to start, even if insulation resistance is satisfactory, some coils may broken.
Measurement of conductor resistance
Measuring instrument: Multi-meter
Measuring method: Disconnect power cable from the control panel. Set the multi-meter range to Ωand measure the values U-V, V-W, and W-U of the motor terminals. Measured
values should be almost the same.
* Motor coil resistance varies according to out put and usually indicates several Ω values, it is difficult to
take a precise measurement with a multi-meter. Thus measured values can be a standard to determine
motor condition only.
* As a result of measurement, decisions can be made as follows: (∆Connection motor)
(1) When a single phase coil is broken between U and V (Fig.7-3), resistance between U and V becomes
twice that of two-phase coil.
Example: UV=4ΩVW=2ΩUW=2Ω
(2) When two-phases of the coil (between U-V and U-W) are broken (Fig.7-4), resistance between U-V and
V-W becomes ∞Ω. Resistance between U-W may have several Ω values.
Fig. 7-4
Fig. 7-3
337. ELECTRICAL INSPECTION
m-2 CHECKING VOLTAGE(1) Voltage measurement at terminals R, S, and T.
This measurement is taken to determine if there is an abnormality in the power supply on the primary
side from the power panel.
Measuring instrument: Multi-meter
Measuring method: If the voltages measured between R-S, S-T, and R-T are within 10% of
normal voltage.
However, when the voltages are unbalanced (more than 3%), an overcurrent is frequently the cause.
Also, should voltage decrease during pump operation, it may be that the power cable is too small or the
amount of power received is too low.
Should this be the case, a competent electrician should make an inspection.
(2) Voltage measurement at terminals, U, V, and W.
Measuring instrument: Multi-meter
Measuring method: When no abnormality is detected in the voltage measured at terminals
R, S, and T, remove the wiring to the motor and check the voltage at
terminals U, V, and W with the panel operating. If voltage at each
phase is normal, it can be considered there is trouble in the control
panel.
m-3 MOTOR PROTECTOR(1) MCB (Molded case circuit breaker)
The characteristics of a Motor MCB are the same as those for a general-purpose motor, submersible
motor should be used thermal relay or 3E relay.
(2) Thermal relay
(a) Method of Installation
Use a screwdriver to align the dial with set pointer.
(b) Normal condition
Return lever does not project.
(c) Abnormal condition
Return lever projects.
(d) Returning method
Check the affected parts and depress the return lever in the
direction of arrow.
Fig. 7-5
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