Volume washer pump issues.

[pappuller]

We have a 140l/min volume washer pump with a 2.65kw motor on a pressure switch that supplies 2 header tanks and 4 water troughs around our robotic milking system.
The pump is fed from a 5000l clean water tank which always has plenty of water in it.
We are finding that the pressure switch on the pump is kicking out of service randomly possibly a couple of times every 24 hrs or so, this is leading to a lack of water for the system at some points during the day/night.
The pump was serviced and a new seal kit installed and a new pressure switch fitted as the same problem was occurring with the original pressure swith, which leads me to think it is a pump issue.
Any ideas would be greatly appreciated as it is becoming a pain in the butt !!!

 

[Kiwi Pete]

When you say the pressure switch is kicking out, does it not start the pump or not stop the pump (leading to it overheating and tripping out)?

Is air possibly an issue, if there is any way air can be trapped in your plumbing then that could be the issue, as it will keep compressing and then the pump will cavitate.

We sometimes leave our kitchen sink tap trickling with the supply pump turned off to prevent the pipe freezing, but if someone flushes the toilet then air is let in the system and the pump never quite gets to the pressure to switch off.

So I adjusted the pressure on the little screw downwards just a couple of psi, and bleed the air out via the shower, which is the highest point.

But, a pump not starting can be the capacitor as well as the switch, do you know if they checked it? Most electric motors will have say a 65 microfarad capacitor, and these can be breaking down without completely failing, which doesn't give enough oomph to start the motor... but current will still be applied, which can lead to thermal protection kicking in.

 

[Will Blackburn]

Does it kick out and stay out?

 

[pappuller]

Does it kick out and stay out?

Pressure switch trips out and stays out, it is wired through a contactor which iam told should reduce the loading when the pump stops and starts

 

[Will Blackburn]

Pressure switch trips out and stays out, it is wired through a contactor which iam told should reduce the loading when the pump stops and starts

You've had it replaced yet it sounds like it's not set up right. I've had one wear out a spring a while ago but that was old.

 

[pappuller]

Hopleys coming Monday, test the capacitor