Grundfos BoosterpaQ Hydro MPC, Инструкция по установке и эксплуатации

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12. Fault finding chart
Warning
Before making any connections in pumps, terminal boxes or breaker cabinet, make sure that the electricity supply
has been switched off for at least 5 minutes and that it cannot be accidentally switched on.
Fault Possible cause Remedy
Pumps do not run when started. Current pressure is higher than or equal to
the setpoint. Wait until the pressure has dropped or lower
the pressure on the discharge side of the
Hydro MPC and check that the pumps start.
Electricity supply disconnected. Connect the electricity supply.
Main switch cut out. Cut in the main switch.
Main switch is defective. Replace the main switch.
Motor protection is activated. Contact Grundfos.
Motor is defective. Repair or replace the motor.
Pressure transmitter fault
- Pressure transmitter is defective. Replace the pressure transmitter.
Transmitters with 0-20 mA or 4-20 mA
output signals are monitored by Hydro MPC.
- Cable is broken or short-circuited. Repair or replace the cable.
The pumps start, but stop immediately.
The operating pressure is not reached. Dry running or no inlet pressure. Re-establish the supply of water to the
Hydro MPC. When the inlet pressure has
been re-established, the pumps will restart
after 15 seconds.
The Hydro MPC is stopped and cannot
restart. Pressure transmitter fault
- Pressure transmitter is defective. Replace the pressure transmitter.
Transmitters with 0-20 mA or 4-20 mA
output signals are monitored by the
Hydro MPC.
- Cable is broken or short-circuited. Repair or replace the cable.
CU 351 fault
- Electricity supply disconnected. Connect the electricity supply.
- CU 351 defective. Contact Grundfos.
Unstable water delivery from Hydro MPC
(applies to unstable water supply). Inlet pressure is too low. Check the suction pipe and possible suction
strainer.
Suction pipe or pumps partly blocked by
impurities. Clean the suction pipes or pumps.
Pumps suck air. Check the suction pipe for leakages.
Pressure transmitter defective. Replace the transmitter.
Pumps are running, but deliver no water. The valves are closed. Open the valves.
Suction pipe or pumps blocked by
impurities. Clean the suction pipe or pumps.
Non-return valve blocked in closed position. Clean the non-return valve. The non-return
valve must move freely.
Suction pipe leaky. Check the suction pipe for leakages.
Air in suction pipe or pumps. Vent and prime the pumps. Check the
suction pipe for leakages.
The Hydro MPC is unable to reach the
setpoint. Too high consumption. - Reduce consumption (if possible).
- Install a bigger Hydro MPC booster set.
Leakage from the shaft seal. Shaft seal is defective. Replace the shaft seal.
Height adjustment of pump shaft inaccurate. Readjust the shaft height.
Noise. The pumps are cavitating. Clean the suction pipe/pumps and possibly
the suction strainer.
The pumps do not rotate freely (friction
resistance) due to inaccurate height
adjustment of the pump shaft. Readjust the shaft height.
Very frequent starts and stops. Wrong diaphragm tank precharge pressure. Set correct precharge pressure.
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