# Hot Tub GFI Trip - Strange!?!?!?



## 480sparky (Feb 1, 2009)

Winchester said:


> you could clamp the wires and check the load before and after. maybe the pump motor is drawing too much when he gets in?
> 
> However, I'd do what 480sparky said first :thumbup:


Like I said... the average amp meter is not going to be sensitive enough to detect that small of a leak. The everyday clamp meters may read down to 1/10th of an amp, _maybe_ 1/100th of an amp. GCFIs read current down to 1/1000th of an amp. 

Besides, how do you clamp both wires at the same time to compare the current flow through them?


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## mrmike (Dec 9, 2008)

480sparky said:


> Like I said... the average amp meter is not going to be sensitive enough to detect that small of a leak. The everyday clamp meters may read down to 1/10th of an amp, _maybe_ 1/100th of an amp. GCFIs read current down to 1/1000th of an amp.
> 
> Besides, how do you clamp both wires at the same time to compare the current flow through them?


 Check current flow in this situation- don't know where your coming from here???? Are you looking for Current loss to ground??? How do you determine where the extra amperage is going, when taking readings with an Amprobe?? Small of a leak ??? You lost me here? What are your reference points to ground?? What are you going by???


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## firemike (Dec 11, 2005)

We've had the service tech out from the hot tub company (still under warranty) and he could not find anything out of the ordinary. He verified electrically it is hooked up properly, there is no leak anywhere, the wire comes up through a 2" PCV conduit from under the concrete the tub is sitting on into the wiring compartment, tightened all the connections, amped out the motor and heater. He (the tech) even filled up the tub with water to the top and it ran fine for four days, even with the control panel under water. The electrician also checked it over and he couldn't find anything. He has done probably three dozen hot tubs for me over the years and dozens on his own so it's not like he is inexperianced. 

There is nothing electrical under the seats, only piping. Everything electrical in in the end service equipment compartment. A small ribbon cable goes through a piece of 1" pvc through the foam to the control panel, that's it. I agree that the place to start is replacing the GFI breaker, but you would think it would trip at other times too. It's got everyone stumped......


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## Winchester (Jun 29, 2008)

480sparky said:


> Like I said... the average amp meter is not going to be sensitive enough to detect that small of a leak. The everyday clamp meters may read down to 1/10th of an amp, _maybe_ 1/100th of an amp. GCFIs read current down to 1/1000th of an amp.
> 
> Besides, how do you clamp both wires at the same time to compare the current flow through them?


I was thinking if the the pump motor was getting weak or had a problem you might trip the breaker (not necessarily ground fault).

Assuming it behaves the same each time it trips, you could clamp one at a time if you needed to...

I've fixed a few hot tubs where the problem was already known, never really had to troubleshoot one. I am only an electrical apprentice. (still registered under my electrical sub, too:laughing


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## Magnettica (Dec 19, 2006)

mrmike said:


> Check current flow in this situation- don't know where your coming from here???? Are you looking for Current loss to ground??? How do you determine where the extra amperage is going, when taking readings with an Amprobe?? Small of a leak ??? You lost me here? What are your reference points to ground?? What are you going by???



I believe he's talking about the 4-6 milliamps it takes to set off the GFCI protection.


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## 480sparky (Feb 1, 2009)

mrmike said:


> Check current flow in this situation- don't know where your coming from here???? Are you looking for Current loss to ground??? How do you determine where the extra amperage is going, when taking readings with an Amprobe?? Small of a leak ??? You lost me here? What are your reference points to ground?? What are you going by???


I'm not 'going by' anything. I'm simply trying to understand how a $100 Fluke amp clamp meter can detect where a ground fault is.

If the meter reads 12.45 amps on the hot, and 12.45 amps on the neutral (not at the same time, mind you.... you need to move the meter from one wire to the other) what will that tell you?

Now, cause a 0.008a ground fault (enough to trip a GFCI), and your meter will read..... guess what: 12.45 amps! OK, let's say it rounds off and reads 12.46 amps. Which wire was that on? What was the exact current flow on the other at that exact same time? No way to know.... your meter isn't sensitive enough and cannot read the amp flow on two wires at the same time. And even if it did, could you see both the readings at the same time?


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## Cow (Jan 7, 2008)

Just my experience, I operate on the trust but verify method with customers(especially homeowners). 

I haven't seen you mention in your posts that you've actually witnessed the problem yourself. Somebody needs to get in the tub while you're present(even if it's you) so you can see the problem firsthand.


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## Stubbie (Aug 10, 2008)

After reading this I think the tub and gfci/disconnect are fine. Maybe a jealous neighbor practical joking with some rf??


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