14
Fault
Possible Cause
1. Motor does not run when started
A. Power failure
B. Fuses blown
C. Motor starter overload has tripped out
D. Main contacts in motor starter are not making contact or the coil is faulty
E. Control circuit fuses are defective
F. Motor is defective
2. Motor starter overload trips out
immediately when power supply is
switched on
A. One fuse has blown
B. Contacts in motor overload relay are faulty
C. Cable connections are loose or faulty
D. Motor winding is defective
E. Pump mechanically blocked
F. Overload setting is too low
3. Motor starter overload trips out
occasionally
A. Overload setting is too low
B. Low voltage at peak times
4. Motor starter has not tripped out but
the motor does not run
A. Check 1A, B, D and E
5. Pump capacity is not constant
A. Pump inlet pressure is too low
B. Suction pipe/pump partly blocked
C. Pump is sucking air
6. Pump runs but gives no water
A. Suction pipe/pump blocked
B. Foot or nonreturn valve is blocked in closed position
C. Leakage in suction pipe
D. Air in suction pipe or pump
E. Motor rotates in the wrong direction
7. Pump runs backward when
switched off
A. Leakage in suction pipe
B. Foot or nonreturn valve is defective
C. Foot valve is blocked in open or partly open position
D. Nonreturn valve leaks or is blocked in open or partly open position
E. Discharge valve is defective
8. Leakage from shaft seal
A. Pump shaft position is incorrect
B. Shaft seal is defective
9. Noise
A. Cavitation is occurring in the pump
B. Pump does not rotate freely (there is increased frictional resistance) because of
incorrect shaft position
TROUBLESHOOTING GUIDE
Warning:
Hazardous Voltage and Risk of Sudden Starts
Disconnect all power to the pump before servicing or working on pump. Make sure that power is locked out and that pump cannot be
accidentally started.