The Pump Runs At Reduced Performance; Frequent Starts And Stops; How To Check The Powersupply; Megging - Grundfos SQF Manual Del Usuario

9.3 The pump runs at reduced performance

Cause
The drawdown is larger than anticipated.
The outlet valve is partly closed or blocked.
The outlet pipe is partly clogged by impurities (ochre).
The non-return valve is partly blocked.
The pump and the riser pipe are partly clogged by impurities (ochre).
The pump is defective.
Leakage in the pipes.
Leakage in the riser pipe.
Low power has occurred.

9.4 Frequent starts and stops

Cause
The difference between start and stop level is too small.
Level sensor is activated.
The non-return valve is leaking or stuck half-open.
The supply voltage is unstable.
Low power supply.
The motor temperature is too high.
9.5 How to check the power supply
DANGER
Electric shock
Death or serious personal injury
‐
Switch off the power supply before you start any work on the product.
1. See the Grundfos service instruction by scanning the QR code.
http://net.grundfos.com/qr/i/96547278
2. Follow the instructions for the relevant system issued in the Grundfos service instruction.

9.6 Megging

Do not meg an installation incorporating this product as the built-in electronics may be damaged.
20
Remedy
Lower the pump deeper into the borehole, throttle the pump or
replace it with a smaller model to obtain a lower performance.
Clean the outlet valve or replace it, if necessary.
Clean the outlet pipe or replace it, if necessary.
Remove the pump from the borehole and clean or replace the non-
return valve.
Remove the pump from the borehole. Clean or replace the riser pipe
or the pump, if necessary.
Have the pump repaired or replaced.
Repair or replace the pipes, if necessary.
Repair or replace the riser pipe.
Ensure sufficient power from the power source. Check the specified
voltage output from the power source.
Remedy
Increase the differential.
Lower the pump deeper into the borehole, throttle the pump or
replace it with a smaller model to obtain a lower performance.
Remove the pump from the borehole and clean or replace the non-
return valve, if necessary.
Ensure sufficient power from the power source. Check the specified
voltage output from the power source.
Ensure sufficient power from the power source.
Check the water temperature and secure sufficient flow around the
motor. If necessary, remove the pump from the borehole and add a
flow sleeve for cooling.