Fault Finding The Product - Grundfos SB Series Installation And Operating Instructions Manual

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.
See also the quick guide.
Fault
1. The pump does not
run.
8
Cause
a) The fuses in the electrical
installation are blown.
b) The residual-current circuit
breaker, RCCB, has tripped.
c) No power supply.
d) The motor protection has cut off
the power supply due to overload.
e) The pump or the power supply
cable is defective.
f) The float switch is in dry-running
position.
g) SBA: The dry-running protection of
the pump has stopped the pump.
h) The pump is blocked.
Remedy
Replace the fuses. If the new fuses blow
too, check the electrical installation and
the power supply cable.
Cut in the circuit breaker.
Contact the power supply company.
Check if the pump is blocked.
1. Switch off the power supply to the
pump.
2. Remove the rubber plug (25). See
figures 1 and 2 on pages
3. Try to turn the pump shaft with a
screwdriver.
4. If the pump shaft is stuck, follow the
instructions in point 1, h.
Note: Remember to refit the rubber plug
(25).
Repair or replace the pump or cable.
Check the water level and the float switch
for free movability.
Note: If the tank is empty, and the float
switch is often in this position, install a
larger tank.
Check the water level.
Switch off the power supply and wait 2
minutes before switching it back on.
Check and clean the pump.
1. Switch off the power supply to the
pump.
2. Remove the eight screws (84b) with a
cross-head screwdriver.
3. Remove the pump base (56). See
figures 1 and 2 on pages
4. Clean the inlet strainer and hydraulic
parts with a brush and a water jet.
5. Reassemble the pump.
11 and 12.
11 and 12.