Table of Contents
Advertisement
10. Fault Finding Chart
Before making any connections in pumps, terminal
boxes or controllers, the electricity supply must be
switched off.
Fault
1. Motor does not run when
started.
2. Motor starts, but stops im-
mediately afterwards.
3. Unstable water delivery
from Hydro 2000 S (ap-
plies only to very low con-
sumption).
4. Pumps are running, but
deliver no water.
5. Leakage from the shaft
seal.
6. Noise.
7. Very frequent starts and
stops.
Cause
a) Electricity supply disconnected.
b) Automatic circuit breakers cut out.
c) Motor protection activated.
d) Fuse in the PFU 2000 defective.
e) Motor defective.
a) Fault in pressure transmitter.
b) Dry running or no pre-pressure. The op-
erating pressure is not reached.
a) Pre-pressure too low.
b) Suction pipe/pumps partly blocked by
impurities.
c) Pumps suck air.
d) Pressure transmitter defective.
a) Suction pipe/pumps blocked by
impurities.
b) Non-return valve blocked in closed posi-
tion.
c) Suction pipe leaky.
d) Air in suction pipe/pumps.
e) Motors running with the wrong
direction of rotation.
a) Shaft seal defective.
b) Height adjustment of pump shaft
inaccurate.
a) The pumps are cavitating.
b) The pumps do not rotate freely
(frictional resistance) due to inaccurate
height adjustment of the pump shaft.
a) Wrong diaphragm tank precharge pres-
sure.
Remedy
Connect the electricity supply.
Correct the fault and cut in the automatic circuit break-
ers.
Correct the fault and reactivate the motor protection.
Replace the fuse.
Repair/replace the motor.
Replace the pressure transmitter. Transmitters with
0-20 mA or 4-20 mA output signals are monitored by
the PFU 2000.
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.
Check the suction pipe and possible suction strainer.
Clean the suction pipe/pumps.
Check the suction pipe for leakages.
Replace the transmitter.
Clean the suction pipe/pumps.
Clean the non-return valve. The non-return valve must
move freely.
Check the suction pipe for leakages.
Vent the pumps. Check the suction pipe for leakages.
Change the direction of rotation.
Replace the shaft seal.
Readjust the shaft height.
Clean the suction pipe/pumps and possibly the suction
strainer.
Readjust the shaft height.
Check the diaphragm tank precharge pressure.
29
Advertisement
Table of Contents
