Fault Finding - Grundfos SRP Installation And Operating Instructions Manual

10. Fault finding

Warning
Before starting any work on the pump, make sure
that the fuses have been removed or the mains
switch has been switched to off. Make sure that
the power supply cannot be accidentally
switched on.
All rotating parts must have stopped moving.
Warning
All regulations applying to submersible
recirculation pumps installed in potentially
explosive environments must be observed.
Make sure that no work is carried out in
potentially explosive environment.
Keep a service log.
Fault Cause
1. The pump does not a) No power supply or supply failure.
start.
b) Supply cable is faulty.
c) Control system is faulty.
d) Impeller cannot rotate freely.
e) Stator windings are faulty.
f)
g) Different phase voltages.
h) Overload relay is set too low or is faulty.
i)
j)
2. Pump starts, but a) Stator windings are faulty.
stops immediately.
b) Different phase voltages.
c) Overload relay is set too low or is faulty.
d) Leak sensor has cut out the pump.
e) Humidity in motor.
3. No liquid or a) Impeller rotates in the wrong direction.
inadequate quantity
b) Pump runs on two phases.
is pumped even if the
motor is running.
c) Internal parts are worn.
d) Impeller dirty or damaged.
4. Pump runs unevenly a) Internal parts are worn.
and makes noise.
b) Impeller dirty or damaged.
c) Faulty motor or gearbox roller bearings.
d) Oscillations caused by the installation (resonance).
5. High current and a) Wrong voltage supply or supply failure.
power consumption.
b) Supply cable is faulty.
c) Control system is faulty.
d) Impeller cannot rotate freely.
e) Stator windings are faulty.
f)
g) Internal parts are worn.
h) Faulty motor or gearbox roller bearings.
Motor has cut out because of overheating.
Leak sensor has cut out the pump.
Humidity in motor.
Pump runs on two phases.
Remedy
Call an electrician.
Call an electrician.
Call an electrician.
Clean the impeller and check manually that it can
rotate freely.
Contact Grundfos.
Wait until the motor has cooled and attempt to
restart the pump.
Call an electrician.
Check the overload relay. Set the relay to the
rated current. See section 7.3 Overload relays.
Contact Grundfos.
Contact Grundfos.
Contact Grundfos.
Call an electrician.
Check the overload relay. Set the relay to the
rated current. See section 7.3 Overload relays.
Contact Grundfos.
Contact Grundfos.
Interchange two phases of the mains supply.
1. Check the electrical connections.
2. Replace faulty fuses.
3. Call an electrician.
Contact Grundfos.
Clean the impeller and inspect for any wear.
Contact Grundfos.
Clean the impeller and inspect for any wear.
Contact Grundfos.
Check installation design.
Call an electrician.
Call an electrician.
Call an electrician.
Clean the impeller and check manually that it can
rotate freely.
Contact Grundfos.
1. Check the electrical connections.
2. Replace faulty fuses.
3. Call an electrician.
Contact Grundfos.
Contact Grundfos.
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