Well pump tripping GFCI

[admo]

Hello everyone, I have setup truck as generator (240v to generator port) for my home fine. I have a neutral switching transfer switch and can power lights and refrigerators and freezers fine (the open neutral issue is solved). My issue is a GFCI fault (as reported by the truck display) from my well pump immediately when it starts. The well pump is on a 30amp breaker and draws under 15 amps when running, but it's startup/inrush is ~34 amps. My initial thought was "well that's the problem" but my house 30amp breaker is not tripping for this well pump on grid power, additionally I'm seeing some large capacitors in the control box for the pump which I believe is to handle this inrush issue.

The core question I'm trying to solve before spending a lot of money is: my truck is displaying a GFCI fault message. I had thought the GFCI message in the truck was indicating a general breaker issue but doing more reading on these forums I'm seeing other people saying there is also an "overload" message. Does anyone know more detail on this and what specifically either message means?

I read some people use soft starters to smooth out motors with large inrush current issues but the well pump companies here don't know or don't want to talk about them. On the other hand the well pump is 30 years old and I presume out of spec if it is on a 30 amp breaker and can draw more than 30 amps. So I am trying to find ways to figure out if the issue is the inrush current or a true GFCI fault. A well pump with any shorts in its wire or housing would of course trip GFCI leading to me needing to replace the pump, while the in rush issue I might be able to solve with a soft starter but they also have some expense.

I don't have details on the well pump unfortunately, only that it was placed 360 feet down. Some internet reading suggests GFCI faults could also occur from extremely long wire runs but I don't know if 720 feet is considered "extremely long". I do have the full four wires running down the well.

Thank you to anyone who has tips, I have not been able to convince the electrician or well pump company to use their expertise to figure it out. I'm also a bit naive on electrical stuff so I wanted to be really sure before I take a crack at installing a soft starter.

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[Maquis]

It doesn’t surprise me that a 30 year old submersible pump has enough leakage to trip a GFCI.
One possibility is to use an isolation transformer such as this. It would take the truck’s GFCI completely out of the equation.
https://www.digikey.com/en/products/detail/solahd/HS5F7.5AS/10072569?

 

[Ricks Lightning]

I'm not an expert in well pumps, but am in sump pumps, ejector pumps, circulating pumps. The last thing you want on a pump is a gfci breaker. same with a fridge unless you want spoiled food. 30 year old pump is most likely the issue as the same think happens with submersible pumps that sit in the water for a long time.

Rick

 

[Firn]

Traditional house breakers don't trip immediately, which is why they can handle an inrush of 34 amps. The lightning on the other hand will immediately trip.

Soft starts are just for this purpose. It's not traditional for a well pump, which why the well guys don't know about it, but it's pretty common for HVAC systems so go talk to an HVAC guy.

In the end it think a soft start is just what you need.

 

[admo]

Firn's advice differs from Maquis' and returns back to the thought I had that there are different error messages from the Lightning when it disconnects the Pro Power. I am seeing a GFCI message but Firn you suggest something that I believe would be an overload message. If the GFCI message indicates a GFCI fault then a soft starter seems like it would not solve the problem.

This post on these forums triggered my wondering on this, I didn't realize there were two different error messages: https://www.f150lightningforum.com/...er-breaker-with-120v-welder.18452/post-370924

 

[admo]

Thank you both Maquis and Rick, for the information. I am reading up to figure out this isolation transformer thing. Part of the difficulty here is that I have no method to test and confirm either hypothesis (GFCI fault via short versus overloading the circuit) aside from the error message from the truck. I don't believe my multi-meter would show the kind of voltage drop that would trigger the GFCI (Also I hope I said these electrical things correctly).

Although If there is a nicer multi-meter out there that does show this kind of precision that would be cheaper than guessing and installing either solution.

 

[shelnian]

If you try to draw more than 7200 watts, pro-power cuts out and indicates you are drawing more power than it's rated for. You have to reduce the load and then hit the reset button on the Sync screen.

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