Fault in bimetals in motor
Replace defective bimetals (over current
3. The pump does not stop.
Is the pump able to empty
the station to the stop level?
- for leakage in pipe and/or discharge
- that the impeller is not clogged.
WARNING: disconnect power before
- the non-return valve(s).
- that the pump has adequate capacity.
Check the contactor and holding circuit.
4. The pump starts-stops-starts in rapid sequence
Does the pump start due to
backflow which fills sump to
- that the distance between the start and stop
- the non-return valve(s).
- that the riser is not too long without a
Does the contactor’s self-
- the voltage in the control circuit in relation
to the rated voltage on the coil.
5. Pump runs but delivers too little or no water.
Check:
- direction of rotation pump.
- that valves are open and intact.
- that pipes, impeller and strainer are not clogged.
- that the impeller rotates easily.
- that the suction lift has not been altered.
- for leakage in the pump installation.
- for wear on wear ring, impeller, pump casing/flange, suction bottom, diffuser, disc, diffuser.
See also under “Inspection”.
Do not override the motor protection repeatedly if it has tripped.