Grundfos KPC, Installation And Operating Instructions Manual

Page: 10 / 208

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6. 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 pump does
not run. a) The power supply is switched off. Switch on the power supply.
b) The fuses in the installation are blown. Replace the defective fuses.
c) The pump thermal switch has tripped.
See section
3.3 Thermal protection . See
also point 2.
The thermal switch restarts the pump
when the motor has cooled down to
normal temperature.
2. The pump stops
after a short
time of
operation (the
thermal switch
has tripped). a) The temperature of the pumped liquid is
higher than that stated in section
7. Technical data . The motor is
overheated.
The pump starts automatically after
sufficient cooling.
b) The pump is partly or fully blocked by
impurities.
Clean the pump.
c) The water level is too low when the
pump is started. The pump cannot self-
prime. See sections
7. Technical data .
Move the pump to a position with
higher water level, or add water until
the pump starts sucking.
3. The pump runs
but gives
insufficient
water. a) The pump is partly blocked by impurities. Clean the pump.
b) The outlet pipe or hose is partly blocked
by impurities. The hose may be sharply
bent.
Check and clean the non-return valve,
if fitted. Straighten out the hose.
4. The pump runs
but gives no
water. a) The pump is blocked by impurities. Clean the pump.
b) The non-return valve in the outlet pipe or
hose is blocked in closed position or
blocked by impurities. The hose may be
sharply bent.
Check the non-return valve.
Clean or replace the valve, if
necessary. Straighten out the hose.
c) Pumps with float switch: The pump does
not stop because the free cable length of
the float switch is too long.
Reduce the free cable length.