ShinMaywa NORUS CR series, Instruction Manual, Page: 19 / 24

19
9 Troubleshooting
Symptom Cause Solution
1. The pump does
not start, or it
starts but soon
stops again.
Disturbed electric transmission such
as a power outage or low voltage
Poor connection of the power supply
circuit or control circuit
Disconnection or poor connection of
the cable
Open phase
Ground Fault Interrupter (GFI) is
activated
Malfunction of a float switch
The protector is activated because
foreign matter is jamming the pump
or for other reasons.
Burnout of the motor
Contact the utility company or an
electrical contractor.
Inspect/correct the circuit.
Replace the cable, or correct the
wire connection.
Inspect/ Correct the wire connection
and magnetic switch.
Repair the leakage point.
Remove obstacles, and repair or
replace the float switch.
Inspect the pump, and remove
any foreign matter.
Repair or replace the motor.
2. The pump stops
after working for a
while
The protector is activated because
the pump has been operated for too
long with its motor exposed.
The protector is activated due to
high liquid temperature.
Overcurrent
Raise the water level for stopping
the pump.
Lower the liquid temperature.
Refer to the section on
overcurrent.
3. The power supply
protector is
working.
A setting value is incorrect.
A motor abnormality has occurred
(burnout of the motor, a water leak,
etc.)
A 50-Hz pump is operating at 60 Hz.
Replace the protector or input a
correct value.
Repair/Replace the motor.
Check the nameplate, and replace
the pump or the impeller.