Pump tripping out

[oldfitter]

On a 2 pump sewage pumping station, one of the pumps trips out occasionally. Once it is manually reset, it can be started and will pump. Telemetry reports reveal the pump seems to "fail" and send out an alarm 5 minutes after it has stopped. The pump has been split to see whether it is blocked but never is. The pump amps when it runs are ok. Both the pumps autorotate duty, but only one pump ever fails. The electricians cant, wont fault find as they say they need to be present when the fault occurs. I could understand the pump tripping while in operation, but why 5 minutes after it has stopped ?

Any ideas

Thanks

 

[Ziggypump]

Sounds like the pump is shorting out - bad switch or starter? - but good luck with the electricians.

 

[ash9144]

What is the actual sensor that sends out the "fail" alarm? Do you have continuous readings on amps? What do they do right at the time of failure?

 

[Artisi]

Is the motor fitted with thermistors? if yes, it could be a marginal thermistor sensing heat built up after shut down.

 

[oldfitter]

Thanks guys. Have passed the comments on to the electrician. Will post again once resolved.

 

[msquared48]

You might pass on to the electrician to turn of the rock music, then it will not trip out.

Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask

 

[stanier]

Many submersible pumps have a switch to trip the pump if water is detected in the oil seal.