Fault Finding Chart - Grundfos SEG AUTOADAPT Montage- Und Betriebsanleitung

13. Fault finding chart

Warning
Before attempting to diagnose any fault, make sure that the fuses have been removed or the
mains switch has been switched off. It must be ensured that the power supply cannot be
accidentally switched on.
All rotating parts must have stopped moving.
Warning
All regulations applying to pumps installed in potentially explosive environments must be
observed.
It must be ensured that no work is carried out in potentially explosive atmosphere.
Fault
1. The pump does not run.
2. The pump operates, but
the motor stops after a
short while.
3. The pump operates at
below-standard
performance and power
consumption.
4. The pump operates, but
delivers no liquid.
5. The pump is choked up.
13.1 Megging
Megging of SEG pumps is not allowed, as the built-in
electronics may be damaged.
28
Cause
a) The dry-running sensors are not
covered by liquid.
b) Three-phase pumps only:
The pump is connected to the
power supply with a wrong phase
sequence.
c) Fuses in electric installation
blown.
d) Supply failure; short-circuit; fault
in cable or motor winding.
e) Fault in motor electronics.
f) Deposits on level or dry-running
sensors.
a) Impeller blocked by impurities.
Increased current consumption in
all three phases.
b) Increased current consumption
due to large voltage drop.
c) Too high liquid temperature.
d) Too high liquid viscosity.
a) Discharge pipe partly blocked by
impurities.
b) Valves in the discharge pipe
partly closed or blocked.
a) Discharge valve closed or
blocked.
b) Non-return valve blocked.
c) Air in pump.
a) Grinder system is worn.
Remedy
After power-on: Allow the liquid level
to rise until the dry-running sensors
are covered with liquid.
Interchange L1 and L2.
Replace blown fuses. If the new ones
blow too, check the electric
installation and the submersible drop
cable.
Have the cable and motor checked
and repaired by a qualified
electrician.
Have the motor checked and repaired
by a Grundfos service engineer.
Clean the sensor(s).
Clean the impeller.
Check that the supply voltage is
within the range.
Reduce the liquid temperature.
Dilute the liquid.
Clean the discharge port.
Check and clean or replace the
valves, if necessary.
Check the discharge valve, and
possibly open and/or clean it.
Clean the non-return valve.
Vent the pump.
Replace the grinder system.