Grundfos CHI 12, Installation And Operating Instructions Manual

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7. Fault finding chart
8. 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.
Before removing the terminal box cover, make sure that the electricity supply has been switched off.
The pumped liquid may be scalding hot and under high pressure. Before any removal or dismantling
of the pump, the system must therefore be drained or the isolating valves on either side of the pump
must be closed.
Fault Cause
1. Motor does not start when the
motor starter is operated.
a) Supply failure.
b) Fuses blown.
c) Motor starter overload has tripped out.
d) Main contacts in starter are not making contact or the coil is faulty.
e) Control circuit fuses are defective.
2. Starter overload trips out
immediately when supply is
switched on.
a) One fuse is blown.
b) Contacts in overload are faulty.
c) Cable connection is loose or faulty.
d) Motor winding is defective.
e) Pump stiff and not free to run.
f)
Overload setting too low.
3. Motor starter overload trips
out occasionally.
a) Overload setting too low.
b) Periodic supply failure.
c) Low voltage at peak times.
4. Pump does not run when
starter is operated.
a) Check 1 a), b), d) and e).
5. Pump capacity not constant. a) Pump inlet pressure is too low.
b) Suction pipe partly blocked by impurities.
c) Pump takes in air.
6. Pump runs but gives no
water.
a) Suction pipe blocked by impurities.
b) Foot or non-return valve blocked in closed position.
c) Leakage in suction pipe.
d) Air in suction pipe or pump.
7. Pump runs backwards when
switched off.
a) Leakage in suction pipe.
b) Foot or non-return valve defective.
c) Foot valve blocked in open or partly open position.
Subject to alterations.