Recurrent circuit breaker tripping from pump

[dogomai]

I'm hoping someone may have some insight to help with an issue I've been working on all summer.

We recently moved into a home with a 20000 gallon in-ground pool. Ever since opening, we have had issues with tripping of the circuit breakers. We have a sub-panel around the side of the house for only the pool pump, heat-pump, and pool light. Initially, the circuit breaker to the pump was tripping, and we found that it was too old and that the GFCI breakers on the sub-panel could no longer trip, so we replaced the indoor breaker and 2 outdoor breakers including the one to the pump.

Since that time, we've had recurring issues with the breaker to the pump tripping. The pool company has replaced pump twice without change. We've had an electrician out multiple times and have now replaced the wiring from the breaker to the pump without fixing the issue. The pool guy even wired the pump directly into the breaker, and it is still tripping.

When the pump is on, it works wonderfully. No issues with water pressure at all. It mainly seems to trip during the hottest parts of the day. It even ran for a few days in a row this week when it was cloudy and in the 60s-70s F. Occasionally though, it will trip at night. This happens once or twice a week.

At this point, the electrician says it's not an electrical problem, and the pool guy says it's not a problem with their hardware, but clearly something is wrong. Does anyone have some suggestions as to what to do next?

[Denniswiseman]

Don't know if this helps
I had a recent problem where I had an earth stake which worked OK but after some work was done the electrician connected the earth to the house wiring which occasionaly caused the main circuit breaker to trip
After disconnecting the earth stake all seems OK

[NewDIYPool]

After disconnecting the earth stake all seems OK

Let me get it straight, you are recommending people to remove the earth connection to their pump?
Isn't that both illegal, and potentially deadly?

[Teapot1]

Have you tried connecting the pump to a different breaker, could be a faulty breaker, we have the similar fault on a board at work.

[Denniswiseman]

So long as the system is earthed correctly my electrician disconnected the earth stake

[Teapot1]

There are whole other issues with multiple earths, is that the problem you had Dennis?

[Denniswiseman]

There are whole other issues with multiple earths, is that the problem you had Dennis?

My system worked fine with the earth stake, but after more work done by the electrician wih another grid earth it would trip out periodically, disconnecting the earth stake solved it
The equipment used now is far more sensitive to variations in the supply