Jacuzzi and GFI

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I just finished helping a friend energize a second-hand Jacuzzi.

A few issues:

The Jacuzzi came with two hots and a ground, but no neutral. I have a two pole GFI protecting the Jacuzzi, but I only assume that the GFI will function fully without a neutral on the load side.

I should mention that the GFI is in the main panel. There is a disconnect panel by the Jacuzzi but it has a conventional two pole breaker in there.

Apparently the Jacuzzi has an electrical issue of some sort. When I first fired up the GFI breaker it held for about four seconds before it tripped. I tired it three times, and each time it was the same story. When I turned off the breaker in the disconnect panel, the GFI held, so I think I can say that the problem is in the Jacuzzi.

What I wonder is if there is some sort of anomaly due to the lack of a neutral? Is the breaker tripping due to a ground fault, or is there an over current? Possibly I should switch in a conventional breaker to see if it would or would not trip under the same load.

Currently there is no water in the Jacuzzi, so I wonder where a ground fault would be coming from.

But I am also confused as to why the GFI breaker holds for four seconds. I have never seen a dead short hold for even a second. I cannot imagine why the breaker behaves as it does.

Any thoughts?
 
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Bluebinky

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On my jacuzzi, it takes a few seconds for the controller to initialize and start the pump motor(s). Do you hear a relay click?

What size breaker + wire are you using?
 
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On my jacuzzi, it takes a few seconds for the controller to initialize and start the pump motor(s). Do you hear a relay click?

What size breaker + wire are you using?

We have not gotten to the point of starting the pumps, but I take your point that the controller could explain the delay in tripping the breaker. A strong argument for trying a conventional breaker, to eliminate or otherwise the question of a ground fault.

The breakers are 50 amp and the wire is #8.
 

Reach4

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I would start by checking resistance from the isolated Jacuzzi hot wires to grounds. The resistance should be over 20 megohm I would expect.
 

WorthFlorida

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....

Currently there is no water in the Jacuzzi, so I wonder where a ground fault would be coming from. But I am also confused as to why the GFI breaker holds for four seconds. I have never seen a dead short hold for even a second. I cannot imagine why the breaker behaves as it does.

Any thoughts?
Shorts may not trip a GFCI. I've had curcuit breakers trip from overloads and not the GFCI. Read this old post.

https://terrylove.com/forums/index.php?threads/gfci-blows-on-jacuzzi.47990/
 
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WorthFlorida

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.... I should mention that the GFI is in the main panel. There is a disconnect panel by the Jacuzzi but it has a conventional two pole breaker in there.
Any thoughts?

The disconnect at the Jacuzzi is not a breaker but a regular switch (most of the time) that looks like a breaker.
A GFCI in a main panel is both a GFCI and a overload circuit breaker. When it "trips" the little button is pushed to reset the GFCI, then there is the breaker switch for overload. A four second delay sounds like a circuit breaker is tripping, not the GFCI. Maybe the motor is seized or the start capacitor has a short.
How are your resetting it?

GFCI.jpg
 
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Reach4

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How would I test that?
Are you asking how to operate an ohmmeter?

WorthFlorida makes a really good point; you don't know if the breaker is tripping due to ground leakage or overcurrent, but if the trip is fairly consistent at 4 seconds, that sounds like overload. It seems unlikely that a ground fault would do that.

A clamp-around ammeter would be a good tool to measure the current during those 4 seconds to be sure. It takes a lot of current to trip a 50 amp breaker in 4 seconds. I would expect that could take over 100 amps. You might have a hard wiring short.
 

Jadnashua

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A GFCI works by measuring the current moving between the hot and return leads (in 240vac, it's between the two hot leads - what goes out on one, must return on the other). If they are not equal within about 5ma, it should trip to protect you, since that power is going somewhere it is not supposed to. CB are not quite like a fuse, they have trip curves, and while a direct short should cause it to trip quickly, an overload can take time before it occurs.

If you have to ask how to use an ohm meter, maybe it's not the best thing to try to check out!

You must have the power off to use an ohmmeter. The meter puts a small voltage on one lead and measures the voltage it gets through the meter to the other lead. By knowing the internal resistance of the meter and the voltage it is outputting, it can calculate the circuit's resistance based on the voltage drop.

With the power turned off, putting one lead on one of the power inputs and the other on ground should show some reading. If the meter does not have autoranging, you may need to change scales to read the results. Do not be touching the metal leads or the wires, or you'll be measuring your body's resistance, not the circuits.
 

WorthFlorida

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Homeownerinburb you have answered the question, the circuit breaker is tripping? 50 amp? Wow? How about a picture of your GFCI, the disconnect and the electric motor of the tub. A 50 amp breaker is doubtful. Even with an electric heater it would be no more than a 30 amp breaker with 10 gauge wire. Someone may have installed a 50 amp in replace of a 30 amp because the 30a was tripping and the 50a was not. I've seen this.

jadnashua is very good on his thoughts, knowledge and how to's but if you do know how to use an ohm meter it doubt's your skills. Finding a short can be easy if you know what your looking for but checking an AC motor with an ohm meter takes skill. You can have a new motor and the ohm readings on a AC motor is very low and it might look like a short when it's not. AC motor resistance is in "impedance" when powered up and running, not ohms.

You're dealing where water and electric mix and it seems that this is beyond your skills. Someone can be hurt. Read the third pinned post on this blog! An electrician is far cheaper than an emergency room visit.
 
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A 50 amp breaker is doubtful. Even with an electric heater it would be no more than a 30 amp breaker with 10 gauge wire. Someone may have installed a 50 amp in replace of a 30 amp because the 30a was tripping and the 50a was not.

You missed reading that I was the one who installed the 50 amp GFI. I purchased a Jacuzzi disconnect and that was what was packaged in it.

I've installed a few Jacuzzis, and seen others installed, and they were ALL protected to 50 amp.

Your doubts of my skills are not misplaced to the extent that I would not expect to troubleshoot the motor in a Jacuzzi. I am looking for tips, but am inclined to get a specialist to take over if nothing obvious leaps out at me.

And thanks for reminding me of the purpose of a GFI. I think I already understood it.
 

Jadnashua

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FWIW, I never said to measure from hot to hot, which would be across the motors and potentially the heater! I said to measure from a hot to ground to see if there was a short or a low enough resistance to create a problem. On a 240vac system without a neutral, you should have NO continuity between them. If it's low enough, enough current will flow to trip a GFCI, and maybe a circuit breaker as well. One needs to read carefully, otherwise, you can create a hazardous situation. I also stressed to do this with the breaker turned off. Having spent years fixing radars and missile launchers, I have a pretty good idea on how to use a meter safely. Hopefully, if you read carefully, you will be safe using one, and if you have some understanding, you might actually figure out what's going on...those two do not always come together!
 
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FWIW, I never said to measure from hot to hot, which would be across the motors and potentially the heater! I said to measure from a hot to ground to see if there was a short or a low enough resistance to create a problem. On a 240vac system without a neutral, you should have NO continuity between them. If it's low enough, enough current will flow to trip a GFCI, and maybe a circuit breaker as well. One needs to read carefully, otherwise, you can create a hazardous situation. I also stressed to do this with the breaker turned off. Having spent years fixing radars and missile launchers, I have a pretty good idea on how to use a meter safely. Hopefully, if you read carefully, you will be safe using one, and if you have some understanding, you might actually figure out what's going on...those two do not always come together!


Yes, I took all that, thank you.
 

Reach4

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You might want to also measure resistance across hots with the breaker open. In that case, less than maybe 2.5 or 3 ohms would maybe indicate a short-- at least I would then check further. I said maybe. I am not sure where you would draw the line, but tripping a 240 volt 50 amp breaker in 4 seconds would take a pretty low resistance.
 
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I'm assuming there IS a short of some sort, or a motor that has frozen up.

My friend knew there were issues with the Jacuzzi and he intends to isolate components from the circuity in the hopes of finding the culprit.

Any thoughts on how practical this approach would be?
 

Jadnashua

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A peak reading, clamp-on ammeter might help. If the motor has a plug to it, or it can easily be disconnected, I'd try that and then apply power. If it still trips the breaker, it's not the motor, it's the controller.
 
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