Grundfos CM series, Service Instructions Manual

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6. Fault finding
DANGER
Electric shock
Death or serious personal injury
‐
Before starting any work on the product, make sure that the power supply has been switched off and that it cannot be accidental-
ly switched on.
WARNING
Corrosive liquids
Death or serious personal injury
‐
Wear personal protective equipment.
WARNING
Toxic liquids
Death or serious personal injury
‐
Wear personal protective equipment.
WARNING
Hot liquid
Death or serious personal injury
‐
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.
CAUTION
Hot or cold liquid
Minor or moderate personal injury
‐
Wear personal protective equipment.
CAUTION
Back injury
Minor or moderate personal injury
‐
Use lifting equipment which is approved for the weight of the product.
‐
Use a lifting method suitable for the weight of the product.
‐
Wear personal protective equipment.
6.1 The pump does not run.
Cause Remedy
Supply failure. • Switch on the switch.
• Check cables and cable connections for defects and loose
connections.
Fuses are blown. • Check cables and cable connections for defects, and replace the
fuses.
Motor protection tripped. • Check cables and cable connections for defects and loose
connections.
• Replace the contacts of the motor-protective circuit breaker, the
magnet coil or the entire motor-protective circuit breaker.
• Check cables and cable connections for defects, and replace the
fuses.
• Repair or replace the motor.
• Switch off the electricity supply, and clean or repair the pump.
• Set the motor-protective circuit breaker according to the rated
current of the motor (I
1/1
). See nameplate.
Control-current circuit defective. • Repair or replace the control-current circuit.
6.2 Motor-protective circuit breaker has tripped (trips out immediately when supply is switched on).
Cause Remedy
Fuses are blown. • Check cables and cable connections for defects, and replace the
fuses.
Contacts of the motor-protective circuit breaker or magnet coil
defective. • Replace the contacts of the motor-protective circuit breaker, the
magnet coil or the entire motor-protective circuit breaker.
Cable connection is loose or faulty. • Check cables and cable connections for defects, and replace the
fuses.
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English (GB)