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English (US)
8. Fault finding the product
DANGER
Electric shock
Death or serious personal injury
- Switch off the power supply before
starting any work on the product.
Make sure that the power supply
cannot be accidentally switched on.
Fault
Cause
Remedy
1.
The motor does
not start.
a)
No power supply.
Connect the power supply.
b)
The fuses are blown.
Replace the fuses.
c)
The motor protection or thermal
relay has tripped. See section
. See also
point 2.
Wait until the motor protection trips in
again or reset the relay.
d)
The impeller is blocked by
impurities.
Clean the impeller.
See section
e)
There is a short circuit in the
cable or motor.
Replace the defective part.
2.
The motor
protection or
thermal relay
trips after a
short time of
operation.
a)
The temperature of the pumped
liquid is too high.
Contact your Grundfos
representative.
b)
The impeller is blocked or partly
blocked by impurities.
Clean the pump. See section
c)
The water level is too low when
the pump is started. The pump
cannot self-prime. See section
.
Move the pump to a position with
higher water level, or add water until
the pump starts sucking.
3.
The pump runs
constantly, but
does not deliver
the rated flow.
a)
The pump is partly blocked by
impurities.
Clean the pump. See section
b)
The outlet pipe or hose is partly
blocked by impurities.
Clean the outlet pipe or hose. Clean
the non-return valve, if fitted.
Straighten out the hose or pipe, if
bent.
4.
The pump runs
but gives no
water.
a)
The pump is blocked by
impurities.
Clean the pump. See section
b)
The pipe or hose is blocked by
impurities.
Clean the outlet pipe or hose.
Clean or replace the non-return
valve, if necessary.
Straighten out the outlet pipe or
hose, if bent.
c)
Pumps with a float switch: The
pump does not stop because the
free cable length of the float
switch is too long.
Reduce the free cable length of the
float switch cable. See section
