Grundfos Hydro 2000 F User Manual

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10. Fault finding chart
Before making any connections in pumps, terminal
boxes or controllers, the electricity supply must be
switched off.
Fault Cause Remedy
1. Motor does not run when
started.
a) Electricity supply disconnected. Connect the electricity supply.
b) Automatic circuit breakers cut out. Correct the fault and cut in the automatic circuit
breakers.
c) Motor protection activated. Correct the fault and reactivate the motor protection.
d) Fuse in the PFU 2000 defective. Replace the fuse.
e) Motor defective. Repair/replace the motor.
2. Motor starts, but stops
immediately afterwards.
a) Fault in pressure transmitter. Replace the pressure transmitter. Transmitters with
0-20 mA or 4-20 mA output signals are monitored by
the PFU 2000.
b) Dry running or no pre-pressure.
The operating pressure is not reached.
Check the supply of water to the pump. When the pre-
pressure has been reestablished, the pump will restart
after 15 secs. and the fault indication will remain.
3. Unstable water delivery
from Hydro 2000 F
(applies only to very low
consumption).
a) Pre-pressure too low. Check the suction pipe and possible suction strainer.
b) Suction pipe/pumps partly blocked
by impurities.
Clean the suction pipe/pumps.
c) Pumps suck air. Check the suction pipe for leakages.
d) Pressure transmitter defective. Replace the transmitter.
4. Pumps are running, but
deliver no water.
a) Suction pipe/pumps blocked by
impurities.
Clean the suction pipe/pumps.
b) Non-return valve blocked in closed
position.
Clean the non-return valve. The non-return valve must
move freely.
c) Suction pipe leaky. Check the suction pipe for leakages.
d) Air in suction pipe/pumps. Vent the pumps. Check the suction pipe for leakages.
e) Motors running with the wrong
direction of rotation.
Change the direction of rotation.
5. Leakage from the shaft
seal.
a) Shaft seal defective. Replace the shaft seal.
b) Height adjustment of pump shaft
inaccurate.
Readjust the shaft height.
6. Noise. a) The pumps are cavitating. Clean the suction pipe/pumps and possibly the suction
strainer.
b) The pumps do not rotate freely
(frictional resistance) due to inaccurate
height adjustment of the pump shaft.
Readjust the shaft height.
7. Very frequent starts and
stops.
a) Wrong diaphragm tank precharge
pressure.
Check the diaphragm tank precharge pressure.

Grundfos Hydro 2000 F Specifications

General

Brand	Grundfos
Model	Hydro 2000 F
Category	Water Pump
Language	English