Fault Finding Chart; Disposal - Grundfos Hydro Dome CHV 2-50 Installation And Operating Instructions Manual

11. Fault finding chart

Warning
Before making any connections in pumps, terminal boxes or control cabinet, the power supply must be switched off.
Fault Cause
1. Motor does not run a) Power supply disconnected.
when started.
b) Motor protection cut out.
c) Motor defective.
2. Motor starts, but stops a) Incorrect setting of pressure switch.
immediately
afterwards.
b) Incorrect tank precharge pressure.
3. Frequent starts and a) Incorrect setting of pressure switch.
stops.
b) Tank defective.
4. Pump is running but a) Suction pipe/pump or discharge pipe blocked
delivers no water.
b) Non-return valve blocked in closed position.
c) Suction pipe leaky.
d) Pump/suction pipe is not filled with water.
e) Air in suction pipe/pump.
f)
g) Three-phase versions:
5. Leakage from the shaft a) Shaft seal defective.
seal.
6. Noise. a) The pump is cavitating.
b) The pump does not rotate freely.
c) Back flow when the pump stops.
7. Leakage from hydraulic a) Mechanical stress on the pump. The manifolds/
chambers.

12. 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.
12
Single-phase: Via built-in thermal switch or
fuses.
Three-phase: Via automatic circuit breaker.
by impurities.
Suction head is too high.
Motors running with the wrong direction of
rotation.
pipes are not supported.
Remedy
Connect the power supply.
Correct the fault. Await automatic resetting of the
built-in thermal switch, replace fuses (single-phase)
or cut in the automatic circuit breaker.
Repair/replace the motor.
Increase the cut-out pressure and/or differential
pressure (Δp).
Check the tank precharge pressure.
Increase the cut-out pressure and/or differential
pressure (Δp).
Repair the tank.
Clean the suction pipe/pump or discharge pipe.
Clean the non-return valve.
Repair the suction pipe.
Refill the pump/suction pipe.
Vent the pump. Check the suction pipe for leakages.
Check the NPSH value and modify the installation,
if necessary.
Change the direction of rotation.
Replace the shaft seal.
Clean the suction pipe/pump and possibly the
suction strainer.
Support the manifolds/pipes with strong and
appropriate support.
Change or clean the non-return valve.
Support the manifolds/pipes with strong and
appropriate support.
Subject to alterations.