Grundfos SQ User Manual

15
9. Fault finding chart
Before starting any work on the pump/motor, make sure that the electricity supply has been
switched off and that it cannot be accidentally switched on.
Fault Cause Remedy
1. The pump does
not run.
a) The fuses in the electric installation
are blown.
Replace the blown fuses. If the new ones
blow too, the electric installation and the
submersible drop cable should be checked.
b) The ELCB or the voltage-operated
ELCB has tripped out.
Cut in the circuit breaker.
c) No electricity supply. Contact the electricity supply authorities.
d) The motor protection has cut off the
electricity supply due to overload.
Check whether the motor/pump is blocked.
e) The pump/submersible drop cable
is defective.
Repair/replace the pump/cable.
f) Overvoltage or undervoltage has
occurred.
Check the electricity supply.
2. The pump runs but
gives no water.
a) The discharge valve is closed. Open the valve.
b) No water or too low water level in
borehole.
See item 3 a).
c) The non-return valve is stuck in its
closed position.
Pull out the pump and clean or replace the
valve.
d) The suction strainer is choked up. Pull out the pump and clean the strainer.
e) The pump is defective. Repair/replace the pump.
3. The pump runs at
reduced capacity.
a) The drawdown is larger than
anticipated.
Increase the installation depth of the pump,
throttle the pump or replace it by a smaller
model to obtain a smaller capacity.
b) The valves in the discharge pipe
are partly closed/blocked.
Check and clean/replace the valves, if
necessary.
c) The discharge pipe is partly choked
by impurities (ochre).
Clean/replace the discharge pipe.
d) The non-return valve of the pump is
partly blocked.
Pull out the pump and check/replace the
valve.
e) The pump and the riser pipe are
partly choked by impurities (ochre).
Pull out the pump. Check and clean or
replace the pump, if necessary. Clean the
pipes.
f) The pump is defective. Repair/replace the pump.
g) Leakage in the pipework. Check and repair the pipework.
h) The riser pipe is defective. Replace the riser pipe.
i) Undervoltage has occurred. Check the electricity supply.

Grundfos SQ Specifications

General

Motor	Permanent magnet motor
Material	Stainless steel
Protection class	IP68
Frequency	50/60 Hz
Application	Irrigation, Pressure boosting
Pumped liquid	Water
Power Supply	Single-phase or Three-phase
Operating Temperature	0 - 40 °C