~ 6 ~
10. Fault finding
(Make sure electricity supply has been switched off before attempting to diagnose any fault)
Fault
Cause
10.1. Motor does not start
a. No electricity supply
b. Fuses are blown.
c. Motor overheating relay tripped.
d. Defective magnetic contactors.
e. Control circuit malfunction.
10.2. Motor cut out during operation.
a. Fuses blown or breakers tripped.
b. Overheating relay tripped.
c. Control circuit malfunction.
d. Pump locked up by foreign objects.
10.3. Pumped capacity is not constant.
a. Pump impeller blocked by impurities.
b. Insufficient liquid level in the tank.
(See Sec. 4.1)
10.4. Pump runs but gives no liquid.
a. Suction filter blocked by impurities.
b. Liquid level is too low (See Sec. 4.1)
c. Incorrect rotating direction.
