Grundfos CMB-SP Booster PM2, Supplement To Quick Manual

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8. System without
pressure tank:
The red "Alarm"
indicator light
flashes once per
period. a) Cycling.
A tap has not been closed entirely
after use.
Check that all taps have been closed.
b) Cycling.
There is a minor leakage in the
system.
Check the system for leakages.
9. System with
pressure tank:
The red "Alarm"
indicator light
flashes once per
period. a) Cycling.
The pressure tank has no
precharge pressure, or the tank
size is insufficient. Check the tank precharge pressure, and
recharge the tank, if necessary.
If the size of the pressure tank is
insufficient, set DIP switch 5 to "OFF",
or replace the pressure tank.
See the quick guide.
10. The red "Alarm"
indicator light
flashes twice per
period.
a) Maximum continuous operating
time (30 minutes).
The pump has been running
continuously for 30 minutes. Check the system for leakages.
Disable the function to allow the pump to
run for 30 minutes.
See the quick guide.
11. The red "Alarm"
indicator light
flashes three times
per period, and each
pump start is
delayed a few
seconds.
a) Too many start/stop sequences
within a short period.
The pressure tank has no
precharge pressure, or the tank
size is insufficient. Check the tank precharge pressure, and
recharge the tank, if necessary.
If the size of the pressure tank is
insufficient, set DIP switch 5 to "OFF",
or replace the pressure tank.
b) Too many start/stop sequences
within a short period.
The PM 2 is set to start/stop with
1 bar differential pressure, i.e.
DIP switch 5 is set to "ON", but no
pressure tank has been installed
in the system.
Set DIP switch 5 to "OFF".
12. The red "Alarm"
indicator light
flashes four times
per period.
a) Pressure sensor fault.
Repair or replace the PM unit.
13. The pump
performance is
unstable.
a) Pump inlet pressure too low. Check the inlet conditions of the pump.
b) Suction pipe is partly blocked by
impurities.
Remove and clean the suction pipe.
c) Leakage in suction pipe. Remove and repair the suction pipe.
d) Air in suction pipe or pump. Vent the suction pipe/pump.
Check the inlet conditions of the pump.
14. The pump runs
backwards when
switched off.
a) Leakage in suction pipe. Remove and repair the suction pipe.
b) Foot or non-return valve defective. Remove and clean, repair or replace the
valve.
c) The foot valve is stuck in
completely or partly open position. Remove and clean, repair or replace the
valve.
Self-priming pumps only:
15. The pump
performance is
unstable and the
pump is noisy.
a) The differential pressure across
the pump is too low.
Close the tap gradually until the
discharge pressure is stable and the
noise has ceased.
16. When startup is
attempted, the pump
will start, but delivers
no pressure or flow.
a) Liquid column above non-return
valve in discharge pipe prevents
the pump from self-priming. Empty the discharge pipe. Make sure
that the non-return valve does not hold
back liquid in the discharge pipe.
Repeat the startup procedure.
b) Suction pipe draws in air. Make sure that the suction pipe is
airtight from pump to liquid level.
Repeat the startup procedure.
Fault Cause Remedy