Grundfos SE1 50 Notice D'installation Et De Fonctionnement page 40

10. Fault finding
DANGER
Electric shock
Death or serious personal injury
‐
Before beginning the installation, switch off the power supply and lock the main switch in
position 0. Make sure that the power supply cannot be switched on unintentionally. Any
external voltage connected to the pump must be switched off before working on the pump.
WARNING
Crushing of hands
Death or serious personal injury
‐
Before diagnosing any fault, make sure that the fuses are removed or the main switch is
switched off. Make sure that the power supply cannot be switched on unintentionally. Make
sure all rotating parts have stopped moving.
All regulations applying to pumps installed in potentially explosive environments must be
FM
observed. Make sure that no work is carried out in a potentially explosive atmosphere.
For pumps with sensors, start fault finding by checking the status on the IO 113 front panel.
See installation and operating instructions for IO 113.
10.1 The motor does not start. The fuses blow or the motor-protective circuit breaker
trips immediately
Do not start again!
Cause
Supply failure; short circuit; an earth leakage
fault in cable or motor winding.
Wrong type of fuse.
The impeller is blocked by impurities.
Air bells, float switches, or electrodes are out
of adjustment or defective.
Moisture in the stator housing (alarm). IO 113
interrupts the supply voltage.
The WIO sensor is not covered by oil (alarm).
IO 113 interrupts the supply voltage.
Stator insulation resistance is too low.
10.2 The pump operates but the motor-protective circuit breaker trips after a short
while
Cause
Low setting of the thermal relay in the motor-
protective circuit breaker.
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Remedy
• Have the cable and motor checked and repaired
by a qualified electrician.
• Fit appropriate type of fuses.
• Clean the impeller.
• Readjust or replace the air bells, float switches,
or electrodes.
• Replace the O-rings, the shaft seal, and
moisture switch.
• Check, and replace, the shaft seal, fill up with oil
and reset IO 113.
• Reset the alarm on IO 113, see the installation
and operating instructions for IO 113.
Remedy
• Set the relay in accordance with the
specifications on the nameplate.