Fault Finding; Disposal - Grundfos APG Serie Montage- Und Betriebsanleitung

10. Fault finding

Warning
Before starting fault finding, switch off the
power supply, and make sure that all
rotating parts have stopped moving. Make
sure that the power supply cannot be
accidentally switched on.
Fault
1. Motor does not start. Fuses
blow, or motor starter trips
immediately.
Caution: Do not start again!
2. Pump operates, but motor
starter trips after a short while.
3. Pump operates at below-
standard performance and
power consumption.
4. Pump operates, but supplies
no liquid.

11. 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) Supply failure; short-circuit;
earth-leakage fault in cable or
motor winding.
b) Fuses blow as they are not
the right type.
c) Impeller blocked by impurities. Clean the impeller.
d) Level switch out of adjustment
or defective.
a) Low setting of thermal relay in
motor starter.
b) Increased current
consumption due to large
voltage drop.
c) Impeller blocked by impurities.
Increased current
consumption in all three
phases.
a) Impeller blocked by impurities.
b) Wrong direction of rotation.
a) Discharge valve closed or
blocked.
b) Non-return valve blocked.
c) Air in pump.
Subject to alterations.
Remedy
Have the cable and motor checked
and repaired by a qualified
electrician.
Install fuses of the correct type.
Check the level switch.
Set the relay in accordance with
the specifications on the
nameplate.
Measure the voltage between
motor phases. Tolerance: ± 10 %.
Clean the impeller.
Clean the impeller.
Check the direction of rotation,
and, if necessary, interchange two
phases. See section 8.1 Direction
of rotation.
Check the discharge valve, and
open and/or clean, if necessary.
Clean the non-return valve.
Vent the pump.
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