8.2 TROUBLESHOOTING FEEDWATER PUMP
1. FEEDWATER PUMP
Pump will not run
Connect the electricity supply.
2. Fuses/Circuit Breakers are
blown.
Replace fuses/Circuit Breakers.
3. Motor contactor overload has
tripped out.
Reactivate the motor protection.
Check, the coil is faulty or wiring loose.
5. Control circuit is defective.
Repair the control circuit.
2. Motor starter
overload, trips out
immediately when
supply is switched
on.
1. One fuse/automatic circuit
breaker is blown.
Replace the fuse, reset the circuit breaker.
2. Contacts in motor contactor
overload are faulty.
Replace motor starter contacts.
3. Cable connection is loose or
faulty.
Tighten or replace the cable connection.
4. Motor winding is defective.
6. Overload setting too low.
Set the motor starter correctly.
3. Motor contactor
overload trips out
occasionally.
1. Overload setting is too low.
Set the overload correctly.
2. Low voltage at peak times.
Check the electricity supply.
4. Pump capacity not
constant.
1. Pump inlet pressure is too low
(cavitation).
Check the suction conditions.
2. Suction pipe/pump partly
blocked.
Clean the pump or suction pipe.
Check the suction conditions.
5. Pump runs but gives
no water.
1. Suction pipe/pump blocked.
Clean the pump or suction pipe.
2. Foot or non-return valve
blocked in closed position.
Repair the foot or non-return valve.
3. Leakage in suction pipe.
4. Air in suction pipe or pump.
Check the suction conditions.
5. Pump rotates in the wrong
direction.
Change the direction of rotation of the motor.
6. Boiler feedwater non-return
valve letting water passed the
valve seat.
Check and clean boiler feedwater non-return valve, ensure
it is seating (normally and not allowing water passed.
accompanied by banging in the feedwater tank).
7. Vapour locking of pump.
Allow system to cool down, check steam traps of pump
and check to be sure return lines are not insulated. Check
return tank temperature, if it is above 82 °C vapour locking
of the pump will occur. Inspect check valves. Clean
and replace as needed. Replace pump with multi-stage
centrifugal pump able to cope with 121 °C.
6. Pump runs
backwards when
switched off.
1. Leakage in suction pipe.
2. Foot or non-return valve is
defective.
Repair the foot or non-return valve.
1. Shaft seal is defective.
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