9
English (US)
14. Fault finding chart
Before starting work on the pump, make sure that the electricity supply has been switched off and that it cannot be
accidentally switched on.
Fault Cause Remedy
1. Motor does not run when
started.
a) Supply failure. Connect the electricity supply.
b) Fuses are blown. Replace fuses.
c) Motor starter overload has tripped out. Reactivate the motor protection.
d) Thermal protection has tripped out. Reactivate the thermal protection.
e) Main contacts in motor starter are not making
contact or the coil is faulty.
Replace contacts or magnetic coil.
f) Control circuit is defective. Repair the control circuit.
g) Motor is defective. Replace the motor.
2. Motor starter overload
trips out immediately
when supply is switched
on.
a) One fuse/automatic circuit breaker is blown. Cut in the fuse.
b) Contacts in motor starter overload are faulty. Replace motor starter contacts.
c) Cable connection is loose or faulty. Fasten or replace the cable connection.
d) Motor winding is defective. Replace the motor.
e) Pump mechanically blocked. Remove the mechanical blocking of the pump.
f) Overload setting is too low. Set the motor starter correctly.
3. Motor starter overload
trips out occasionally.
a) Overload setting is too low. Set the motor starter correctly.
b) Low voltage at peak times. Check the electricity supply.
4. Motor starter has not
tripped out but the pump
does not run.
a) Supply failure. Connect the electricity supply.
b) Fuses are blown. Replace fuses.
c) Thermal protection has tripped out. Reactivate the thermal protection.
d) Main contacts in motor starter are not making
contact or the coil is faulty.
Replace contacts or magnetic coil.
5. Pump runs but gives no
liquid or pump capacity
is not constant.
a) Pump strainer partly blocked by impurities. Clean the strainer.
b) Liquid level in tank too low. Increase the liquid level.
c) Pump draws in air. Check the suction conditions.
6. Leakage in shaft seal. a) Shaft seal is defective. Replace the shaft seal.
7. Noise. a) Cavitation occurs in the pump. Check the suction conditions.
b) Pump does not rotate freely (frictional resistance)
because of incorrect pump shaft position.
Adjust the pump shaft.
c) Frequency converter operation. See section 8.1 Frequency converter operation.
CRK_MTR.bk.book Page 9 Thursday, October 25, 2012 5:08 PM
To Next Page
Loading...
