Fault Finding Chart - Grundfos BMP Serie Montage- Und Betriebsanleitung

18. Fault finding chart

Warning
Before starting work on the pump, make sure that the
electricity supply has been switched off and that it
cannot be accidentally switched on.
Fault Possible cause
1. The pump stops during a) No water supply.
operation.
b) The fuses are blown.
c) The motor starter overload unit has tripped.
d) The magnetic coil in the motor starter/
e) The control circuit has cut out or is defective. Check the control circuit and the contacts in the
f)
2. The pump runs, but a) No or insufficient water supply at the pump
gives no water or
develops any pressure.
b) The piping system or pump is choked up.
c) The prefilter is clogged.
d) The pump is worn.
e) Wrong direction of rotation.
3. The pump runs at a) The pump is partly blocked by impurities.
reduced capacity.
b) The pump is defective.
c) The prefilter is clogged.
d) The motor speed is too low.
8
The low-pressure switch has cut out.
The level switch has cut out.
contactor is defective (not cutting in).
The motor/supply cable is defective.
suction port.
Remedy
Check that the low-pressure switch functions normally
and is adjusted correctly.
Check that the minimum inlet pressure is correct. If not,
check the feed pump.
Check the water level in the water tank.
Check and replace the main fuses and/or fuses for
control circuit, if necessary.
Reset the starter overload, see also sections
9.2 Motor protection and 10. Start-up.
Replace the coil. Check the coil voltage.
monitoring devices (low-pressure switch, level switch,
etc.).
Check motor and cable, see section
connection.
Check that the inlet pressure during operation is at least
0 bar, see section 8.1 Inlet pressure.
Restart the pump as described in section
Check the piping system and pump.
Clean the prefilter.
Replace the wear parts. Contact Grundfos Service.
See section 10. Start-up.
Dismantle, clean and check the pump.
Replace defective parts. Contact Grundfos Service.
Replace defective parts. Contact Grundfos Service.
Clean the prefilter.
Check the electricity supply.
Contact the electricity supply authorities, if necessary.
If a frequency converter is used, adjust the speed.
9. Electrical
10. Start-up.