Fault Finding - Grundfos Unilift CC 5 Manual Del Usuario

11. Fault finding

Warning
Before starting work on the product, switch off the power supply. Make sure that the power
supply cannot be accidentally switched on.
Fault Cause
1. The pump does a)
not run.
b)
c)
2. The pump stops a)
after short time
of operation
(thermal switch
tripped).
b)
c)
3. The pump runs a)
but gives
insufficient
b)
water.
c)
4. The pump runs a)
but gives no
water.
b)
c)
5. The pump leaks a)
at the handle
(no fault).
12
Power supply switched off.
Fuses in installation blown.
The pump thermal switch has tripped.
See section 8.5 Thermal
(See also point 2.)
The pumped liquid temperature is
higher than that stated in section
6. Operating conditions.
The motor is overheated.
Pump partly blocked by impurities or
blocked.
Water level too low when the pump is
started. The pump cannot self-prime.
See sections 8.1 Self-venting
8.4 Pumping to low water
Pump partly blocked by impurities.
Discharge pipe/hose partly blocked
by impurities. The hose may be
sharply bent.
Impeller, bottom part or diaphragm
defective.
Pump blocked by impurities.
Non-return valve in discharge pipe/
hose blocked in closed position or
blocked by impurities. The hose may
be sharply bent.
Pumps with float switch: The pump
does not stop because the free cable
length of the float switch is too long.
Pump sucks air or water with a high
air content. See section 8.1 Self-
venting.
Remedy
Switch on the power supply.
Replace defective fuses.
The thermal switch restarts the pump
protection. when the motor has cooled to normal
temperature.
The pump starts automatically after
sufficient cooling.
Clean the pump. See section
9.1 Cleaning.
Move the pump to a position with higher
water level or add water until the pump
and
starts sucking.
level.
Clean the pump. See section
9.1 Cleaning.
Check and clean the non-return valve, if
fitted.
Replace defective parts. See section
12. Service
Clean the pump. See section
9.1 Cleaning.
Check the non-return valve.
Clean or replace the valve, if necessary.
Reduce the free cable length.
See section
length for float
The pump is not damaged. Move the
pump to a place where the water level is
higher.
7.4 Adjustment of cable
switch.