Troubleshooting - EBARA 4WN Series Original Instruction Manual

10. Troubleshooting

Fault
The pump won't start
The pump is running but
not pumping any water
he pump is running but
with reduced performance
Pump switching on and off
frequently
(with installed pressure
compensation tank / pressure switch)
15
Cause
Motor protection switch has been triggered
No power supply
Faulty pump / underwater cable
The water level in the borehole is too low
The non-return valve is closed and blocked
The non-return valve on the pressure side is closed
Motor malfunction
The pump is faulty
The intake screen is blocked
The pressure pipe is partially blocked by dirt,
leaking or damaged
The pump has been immersed too deep into
the borehole and is covered by sand or solids
The non-return valve is only partially open
The intake screen is dirty
Pump getting too hot
Motor malfunction
Inlet pressure in the compensation tank is too
low
Compensation tank too small
Compensation tank membrane damaged
Difference between switch-on and switch-off
pressure set on the pressure switch is too low
System leaking
Action
Remove the plug from the socket for at least one
minute
Have the electrical installation checked by a
qualified electrician
Repair or replace the pump / underwater cable
Reduce the pumping volume; lower the pump
further or use a pump with a smaller output
Pull the pump out of the borehole and clean or
replace the intake screen
Pull the pump out of the borehole and clean or
replace the non-return valve
Open the non-return valve
Motor malfunction
Repair or replace the pump
Pull the pump out of the borehole and clean or
replace the intake screen
Clean the pressure pipe, mend the leak or replace
Reduce immersion depth
Pull the pump out of the borehole and clean or
replace the non-return valve
Pull the pump out of the borehole and clean or
replace the intake screen
Fit the pump with a cooling jacket
Measure motor current
The inlet pressure of the compensation tank should
be about 10 % lower than the pump's switch-on
pressure
Increase the volume of the compensation tank by
installing a further tank or replace
Replace the compensation tank
Increase the pressure difference on the pressure
switch. The switch-on pressure should be about
10 % higher than the pressure of the compensation
tank, but under all circumstances high enough to
ensure that there is an adequate water supply. The
switch-off pressure must not be higher than the
pressure of the compensation tank.
Seal or repair leak in system.