Fault Finding Chart; Related Documentation; Disposal - Grundfos Hydro Multi-S CM Montage- Und Betriebsanleitung

13. Fault finding chart

For faults not listed in this fault finding chart, please refer to the installation and operating instructions for the pumps.
Warning
Before making any work on the booster system, make sure that the power supply has been switched off and that it
cannot be accidentally switched on.
Fault
1. The Hydro Multi-S does
not run when started.
2. Pump starts, but stops
immediately afterwards.
3. Frequent starts and stops. a) Incorrect setting of pressure switch.
4. Pumps are running, but
deliver no water.
5. Pumps run backwards
when switched off.
6. Shaft seal leakage.
7. Noise.

14. Related documentation

For further information about Hydro Multi-S, see WebCAPS on
Grundfos' homepage, www.grundfos.com.

15. Disposal

This product or parts of it must be disposed of in an
environmentally sound way:
1. Use the public or private waste collection service.
2. If this is not possible, contact the nearest Grundfos company
or service workshop.
Cause
a) The actual pressure is higher than or equal to
the cut-in pressure set.
b) Power supply disconnected.
c) Automatic circuit breakers cut out.
d) Motor protection activated.
e) Circuit breaker defective.
f) Pressure switch defective.
g) Fuse defective.
h) Pump blocked.
i) Motor defective.
j) Electronic circuit-board failure.
a) Incorrect setting of pressure switch.
b) Wrong diaphragm tank precharge pressure.
c) Dry-running protection activated.
b) Wrong diaphragm tank precharge pressure.
c) Diaphragm tank defective.
a) Suction pipe/pumps blocked by impurities.
b) Foot or non-return valve blocked in closed
position.
c) Air in suction pipe/pumps.
d) Motors running with wrong direction of
rotation.
a) Leakage in suction pipe.
b) Foot or non-return valve is defective.
a) Shaft seal defective.
a) The pumps are cavitating.
Subject to alterations.
Remedy
Wait until the pressure has dropped, or lower the
pressure on the discharge side of the Hydro Multi-S.
Check that the booster system starts.
Connect the power supply.
Correct the fault, and cut in the circuit breakers.
Contact Grundfos.
Replace the circuit breaker.
Replace the pressure switch.
Correct the fault, and replace the fuse.
Remove the cause of the blocking.
Repair or replace the motor.
Replace the fuse, if defective.
Switch to emergency operation, and replace the
electronic circuit board, if defective.
Increase the cut-out pressure and/or differential
pressure.
Check the precharge pressure.
Check the inlet conditions, and make sure that liquid
flows freely to the pumps.
Increase the cut-out pressure and/or differential
pressure.
Check the precharge pressure.
Repair or replace the diaphragm tank.
Clean the suction pipe/pumps.
Check and repair the valve.
Vent the pumps. Check the suction pipe for
leakages.
Change the direction of rotation (interchange two
phases of the power supply).
Repair or replace the suction pipe.
Repair or replace the valve.
Replace the shaft seal.
Check the suction conditions (pump, pipe, valves
and the suction strainer, if any).
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