17
English (US)
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.
Fault
Cause
Remedy
1. The pump does not
start.
a) No power supply or supply failure.
Call an electrician.
b) Power cable is faulty.
Call an electrician.
c) Control system is faulty.
Call an electrician.
d) Propeller cannot rotate freely.
Clean the propeller and check manually that it can
rotate freely.
e) Stator windings are faulty.
Contact Grundfos.
f)
Motor has cut out because of overheating.
Wait until the motor has cooled and attempt to
restart the pump.
g) Different phase voltages.
Call an electrician.
h) Overload relay is set too low or is faulty.
Check the overload relay. Set the relay to the
rated current. See section 7.3 Overload relays.
i)
Leak sensor has cut out the pump.
Contact Grundfos.
j)
Humidity in motor.
Contact Grundfos.
2. Pump starts, but
stops immediately.
a) Stator windings are faulty.
Contact Grundfos.
b) Different phase voltages.
Call an electrician.
c) Overload relay is set too low or is faulty.
Check the overload relay. Set the relay to the
rated current. See section 7.3 Overload relays.
d) Leak sensor has cut out the pump.
Contact Grundfos.
e) Humidity in motor.
Contact Grundfos.
3. No liquid or inade-
quate quantity is
pumped even if the
motor is running.
a) Propeller rotates in the wrong direction.
Interchange two phases of the mains supply.
b) Pump runs on two phases.
1. Check the electrical connections.
2. Replace faulty fuses.
3. Call an electrician.
c) Internal parts are worn.
Contact Grundfos.
d) Propeller dirty or damaged.
Clean the propeller and inspect for any wear.
4. Pump runs unevenly
and makes noise.
a) Internal parts are worn.
Contact Grundfos.
b) Propeller dirty or damaged.
Clean the propeller and inspect for any wear.
c) Faulty motor or gearbox roller bearings.
Contact Grundfos.
d) Oscillations caused by the installation (resonance).
Check installation design.
5. High current and
power consumption.
a) Wrong voltage supply or supply failure.
Call an electrician.
b) Power cable is faulty.
Call an electrician.
c) Control system is faulty.
Call an electrician.
d) Propeller cannot rotate freely.
Clean the propeller and check manually that it can
rotate freely.
e) Stator windings are faulty.
Contact Grundfos.
f)
Pump runs on two phases.
1. Check the electrical connections.
2. Replace faulty fuses.
3. Call an electrician.
g) Internal parts are worn.
Contact Grundfos.
h) Faulty motor or gearbox roller bearings.
Contact Grundfos.
