1. INSTALLATION PLANNING 1 -...

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 16v-2 Overhaul 17v-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

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3132333536

373737383849494040

414242

464747

484848484951515152

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41

46

48

56

61

11. INSTALLATION PLANNING

z-1 SUCTION LIFT (General Information)Suction lift will be changed according to pump characteristics, type and temperature of the liquid handledand piping conditions. When preparing a plan for installation, the following should be taken intoconsideration.

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 floodedsuction system.

Water temperature Suction lift20: -6m40 -560 -370 -280 0

100 +7

Suction limits

flooded suction isrequired

Fig. 1-1 Fig. 1-2

31

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 insulationresistance 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 asfar 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 oftime. Too, even daily maintenance is apt to be neglected, which will, of course, affect the life of thepump. 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 aprotective covering against rain. When a motor is installed outdoors without covering, insulationresistance 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 aconstruction engineer. Make sure the supports are provided with rubber packing, as shown in thefollowing. (See Fig.1-3)

32


z-3 SUCTION PIPEImproper installation of the suction pipe may be result in failure to pumping. Care should be taken with thefollowing:

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 shouldbe considered that the connections pipe will be greater the possibility of air intrusion.

Fig. 1-3

Fig. 1-4 Fig. 1-5

33


wEnsure piping contains no convex areas which cause airpocketsShould there be a convex area in the suction pipe, when thepump is primed, air will remain in this area. When the pump isstarted, air will be drawn into the pump, and the pump will notoperate.

ePiping layout which facilitates easy removal of suctionpipingOne cause can be a foot valve leak. It the suction pipe can beeasily lifted, inspection and repair can be quickly and efficientlyaccomplished.When planning, it is recommended that use of an EBARAsuction unit be considered.

MSuction UnitThe EBARA suction unit will be used for simplifies pipeinspection from the foot valve to the suction port.

¡Advantages1. The suction pipe can be installed after finishing the

floor surface.2. Lever control of the foot valve may be easily

accomplished at pump level.3. Both foot valve and suction pipe can be inspected at

pump level when the foot valve is lifted together withthe suction pipe, eliminating the need of entering thepit.

Fig. 1-6

Fig. 1-7

Fig. 1-8

34


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 willoperate 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 valveson 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

35


z-5 SELF-PRIMING PUMPAir vent valveAn air vent valve must be installed between the valve and the pump discharge port so as to release the airexhausted during self-priming action. Without this air vent valve, the pump cannot complete its self-primingfunction.

(Model SQ) (Models MSQ)

Fig. 1-12 Fig. 1-13

36

72. INSTALLATION

x-1 CENTERING THE COUPLINGqImportance of centering

When pump and motor are direct coupled, shaft alignment is of primary importance. Alignment is usuallychecked at circumference of coupling.

¡When centering of the coupling is not satisfactory:1) Vibration or noise is made2) Coupling rubber is subject to abnormal wear3) Gland packing is subject to abnormal wear4) 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 areimproper, even the iron base can be distorted and cause misalignment.

Fig. 2-1 Fig. 2-2 Fig. 2-3

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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 aclearance 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 linersLiners should be placed on both sides of each anchor boltand 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 circumferencedifference

2) Coupling surface difference

Fig. 2-4 Fig. 2-5

Fig. 2-7

Fig. 2-6

38

92. INSTALLATION

3) Placing of linersOne of two flat liners and one tapered liner shouldbe used according to the clearance between thecommon base can be raised by driving in atapered liner. (Refer to Fig.2-8.)Large or heavy pumps should be installed asshown in Fig.2-9. Even for a small pump, thismethod permits ideal installation.

4) Direct coupling centeringCentering will not be exceed tolerable value.

x-2 PIPINGqSuction pipe

1) Air pocket preventionThe suction pipe should be installed with anupward inclination of not less than 1/100 toward thesuction port of pump.Should this method be impractical, an air vent valvemust be installed air to escape during priming. (SeeFig.2-12.)If the height of the suction pipe is greater than theposition of the priming funnel, an air vent valve andfunnel should be installed in this area to facilitatepriming. (See Fig.2-13.)

Fig. 2-8

Fig. 2-9

Fig. 2-10

Fig. 2-11

Fig. 2-12 Fig. 2-13

39

10 2. INSTALLATION

2) Seal connections completely.If flange seals or threaded couplings are not fix comptelely, water can not be pumped because of airintrusion.

wDischarge pipeTo avoid excess pipe weight on the pump, supports should beinstalled 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 attachingpipes.Also ensure that the pipes do not contain waste, wood orforeign matter during installation.

Fig. 2-14

Fig. 2-15

Fig. 2-16

Fig. 2-17

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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 leasttwice 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 removedfrom 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 shaftand manually rotate the pump. If the pump can not be turned easily, or the internal components contactthe casing,such distortion may be a result of excessive tightening of the gland packing or excessive pipeloading.

tMotor protectorCheck that capacity of the motor protector is sufficient for the motor. Determine that voltage, phase andfrequency meet with the operating conditions listed on nameplate of the motor.Do not attempt test operation using a temporary power source.

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Direction

12 3. TEST OPERATION

yDirection of motor rotation1) Direct coupling pump (using couplings)

Remove the coupling bolts, operate the motor independently, andcheck direction of rotation. (For a general-purpose pump, correctrotation 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 precedingparagraph(1).

Fig. 3-2

Fig. 3-1

Rotation direction

42

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. (ForModels 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 pipewill 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 abnormalnoise and/or vibration. Should malfunctions be detected, recheck direct coupling centering, rotationdirection 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 operatedcontinuously.

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.

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14 3. TEST OPERATION

Head can be obtained from gauge readings as follows:

Example 1Discharge side gauge reading . . . . . . . .12mSuction side gauge reading . . . . . . . . . . .-4mHead=12-(-4)+=16.2(m)

Example 2Discharge side gauge reading . . . . . . . .12mSuction side gauge reading . . . . . . . . . . . .4mHeight difference of stations . . . . . . . . . .0.2mHead=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 willgenerate heat, sometimes causing seizure.

wElectric currentObserve the control panel ammeter to ensure the current is within the rated value for the motor, asdescribed on the motor nameplate.

eWater volumeIt is difficult to measure the volume of water unless a flow meter is installed. Nevertheless, the amount ofwater discharged can be estimated from the pump characteristic curve.

Fig. 3-3

Fig. 3-4

Fig. 3-5

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153. TEST OPERATION

rGland packing leakageDetermine that the amount of water leakage at gland packing is proper. If there is no leakage, thepacking 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 pipeThe 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). Whenvibration is excessive, check direct coupling centering, faulty piping, loose anchor bolts, etc., and takeremedial measures.

45

16 4. MAINTENANCE

v-1 DAILY MAINTENANCEqChecks on operating condition

If head, electric current, temperature, vibration, noise, etc. are obviously different from those prescribedfor 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.

46

174. MAINTENANCE

eBall bearingsGenerally, bearings should be replaced every two or three years. However, if the pump is installed in anarea with excessive humidity or high ambient temperature, the grease will leak and rusted bearingswhich will curtail service life. If this occurs, the bearings should be replaced immediately.

rLubricationModel MS pumps use sleeve metal and #140 turbine oil or itsequivalent as lubricant. In a new pump, oil should be changedabout once a week during initial stages of operation, and aboutonce every six months thereafter.

v-2 OVERHAULAfter several years, the moving parts in the pump wear and the water passages may become narrow dueto collected rust, resulting in deterioration of performance. The pump should be overhauled once everythree 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

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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 alsoprevents the intrusion of air.The small leakage from gland area has the following three objectives:

(1) Lubricant between gland packing and shaft orsleeve.

(2) Removal of friction-generated heat betweenthe packing and shaft or sleeve.

(3) Prevention of air intrusion at gland area.

wProper leakageA certain amount of water must continuously drip from the glandarea.

eAdjustment(1) Stop the pump and release internal pressure.

Ensure all internal pressure is released before adjustinggland packing.

(2) Do not tighten too much at one time.The gland packing is adjusted by the two gland nuts. Thegland is pushed in by tightening these nuts, thus compressingthe packing. The tightening limit is one turn of the nut. Afterone adjustment, the pump should be operated for 10 to 15minutes disregarding any leakage.

Fig. 5-1

Fig. 5-2

Fig. 5-3

48

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 acorkscrew), will facilitate this operation.Insert the corkscrew into the packing and remove. Be careful not to scratch the shaft or sleeve.

(2) Stuffing box cleaningAll 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

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(3) Packing preparationGland packing used for EBARA standard pumps is cut tothe desired length so that it may be formed into rings. Thispacking is available at all EBARA dealers.(See Fig.5-6)

When using long-size commercial packing, cut it as follows:

Example 1Prepare a round bar with the same diameter as the shaft, windpacking around the bar and cut it.

Example 2Make a packing ring and determine the correct size by inserting itinto the stuffing box. Be sure the ring is cut at a 45°angle.

(4) Inserting packingApplication of a lubricant, such as molybdenum disulfide(commercial brand: Molycoat), to the inner diameter of thepacking, will facilitate insertion.When placing packing on the shaft, open the cross sectionwhile twisting. If it is opened straight, there is a possibilityof breaking on the opposite side.

Push the packing rings into the stuffing box, one by onestaggering their cross sections by 180°.The gland in thestuffing box and tighten nuts.

Fig. 5-6

Fig. 5-8

Fig. 5-9

Fig. 5-7

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b-2 MECHANICAL SEALqFunction

Whereas a gland packing permits water lekage, the mechanical seal eliminates leakage where the shaftpasses through the casing.The following figure shows an example of mechanical seal structure. The mechanical seal consists offloating 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 theseal 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. fromentering 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 sealsurface 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

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eReplacement (Model LPD Line Pump)

Procedure Sketch

1. Turn off power

2. Close both discharge and suction valves.

1. Before disassembly place reference markson the casing and bracket, and the motor tofacilitate reassembly.

2. Remove clamp bolts from both casing andbracket: separate the motor from the casing.The motor can be removed with the impellerattached.

Preparation

Disassembly

3. Straighten the bent portion of the impellernut washer: remove the impeller nut andwasher; remove the impeller.

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Procedure Sketch

6. Push out the fixed side of the mechanicalseal incorporated in the bracket with ascrewdriver shown in the figure at right.Should the rubber packing remain in thebracket, remove by hand.

4. Remove the impeller key before removingthe slinger and rotating portion of themechanical seal.When the rotating portion is difficult toremove, remove it at the same time thebracket is removed, as described in the nextphase of disassembly.

5. Remove the bracket clamping bolts andseparate the motor from the bracket.Even when the rotating portion of themechanical seal remains attached to theshaft, it can be pulled from the shaft byremoving the bracket.

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AssemblyEssentially, assembly is accomplished by reversing the disassembly procedure.Cautions and instructions:

(1) Cleaning mechanical seal chamberRemove all rust and stains from the interior of the bracket.

(2) Installing seal ringInsert the seal ring in the bracket with a lubricant, such as soapy water or molybdenum disulfide.

(3) Installing bracketAttach 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 seatFit the rotating portion of the mechanical seal to the shaft.

(5) Installing slingerWhen installing the slinger align the notch with the tongue of the mechanical seal (directly above thekey way of the shaft).

Fig. 5-11

Fig. 5-12

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(6) Installing impellerInstall the impeller, insert the washer and tighten with the impeller nut. The washer should be bent toprevent rotation of the impeller nut.

(7) Assembling motor and pump casingAttach the motor, with the impeller installed, to the casing.

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26 6. MALFUNCTIONS, POSSIBLE CAUSES AND REMEDIES

MMajor malfunctionsqVibration and noisewExcessive leakage at gland packing or mechanical sealeMotor 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.)

56

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.

Prot

ectiv

e de

vice

oper

ates

afte

r se

vera

l sec

onds

.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 conductorresistance. (See page 31.)

Abnormal panel or power source.

Check that set value of protectormatch with motor rating. (See page 33.)

Inspectionmade by competentelectrician.

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.

57


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.)

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296. MALFUNCTIONS, POSSIBLE CAUSES AND REMEDIES

Intrusion of foreign matter.

Overcurrent:



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.

59


Bearing damage.

Vibration/Noise:



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.

60

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 madewith the cable connected.

Fig. 7-1

Fig. 7-2

61

32 7. ELECTRICAL INSPECTION

(2) Consideration of measured values1)Example

Pump 1 pump 2Oct. 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 resistanceMeasuring instrument: Multi-meterMeasuring method: Disconnect power cable from the control panel. Set the multi-meter range to Ω

and measure the values U-V, V-W, and W-U of the motor terminals. Measuredvalues should be almost the same.

* Motor coil resistance varies according to out put and usually indicates several Ω values, it is difficult totake a precise measurement with a multi-meter. Thus measured values can be a standard to determinemotor 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 andV-W becomes ∞Ω. Resistance between U-W may have several Ω values.

Fig. 7-4

Fig. 7-3

62

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 primaryside from the power panel.Measuring instrument: Multi-meterMeasuring 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 theamount 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-meterMeasuring 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 atterminals U, V, and W with the panel operating. If voltage at eachphase is normal, it can be considered there is trouble in the controlpanel.

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, submersiblemotor 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 thedirection of arrow.

Fig. 7-5

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1. INSTALLATION PLANNING 1 -...

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