Grundfos CMB Instrucciones De Instalación Y Funcionamiento página 8

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