Fault Finding Chart - Grundfos SCALA Installation And Operating Instructions Manual

12.3 Fault finding chart

Warning
Before starting fault finding, switch off the power
supply.
Make sure that the power supply cannot be
accidentally switched on.
Fault
1. The pump is not
running.
2. The pump is
running.
3. Pump performance
is insufficient.
12
Cause
a) Power supply failure
- -
b) The power supply is out of
prescribed voltage range
Yes
c) The shaft seal has seized up
No
d) The pump is blocked by impurities See section
No
e) Dry running
Yes
f) The maximum runtime has been
exceeded
No
g) The internal non-return valve is
No defective or blocked in completely
or partly open position
a) Leakage from the pipework, or
- the non-return valve is not
properly closed due to impurities
b) Small continuous consumption
-
c) The temperature is below freezing
- point
a) The pump inlet pressure is too
- -
low
b) The pump is undersized.
-
c) The inlet pipe, the inlet strainer or
- - the pump is partly blocked by
impurities
d) Leakage in the inlet pipe
- -
e) Air in the inlet pipe or the pump
- -
f) The required outlet pressure is
- -
too low for the installation
g) The maximum temperature has
Yes been exceeded and the pump is
running at reduced performance
Remedy
Switch on the power supply.
Check the cables and cable
connections for defects and loose
connections and check for blown
fuses in the electrical installation.
Check the power supply and the
pump nameplate. Reestablish the
power supply within the prescribed
voltage range.
See section
9. Starting up the product
after shutdown or standstill.
9. Starting up the product
after shutdown or standstill.
Contact Grundfos Service if the
problem persists.
Check the water source, and prime
the pump.
Check the installation for leakage and
reset the alarm.
Clean, repair or replace the
non-return valve. See section
10. Servicing the product.
Check and repair the pipework, or
clean, repair or replace the non-return
valve.
Check the taps and reconsider the
usage pattern (ice machines, water
evaporators for air-conditioning, etc.).
Consider protecting the pump and the
installation against frost.
Check the inlet conditions of the
pump.
Replace the pump with a bigger
pump.
Clean the inlet pipe or the pump.
Repair the inlet pipe.
Prime the inlet pipe and the pump.
Check the inlet conditions of the
pump.
Increase the pressure setting (arrow
up).
Check the cooling conditions. Protect
the pump against direct sunlight or
any nearby heat sources.