GFCI Tripping

[brian_tr]

I had trouble with GFCI Breaker tripping right after replacing a circulation pump.  Swore it was the new pump but ended up being the breaker itself.  Replaced it and know more troubles.

[gmdodt]

I had trouble with GFCI Breaker tripping right after replacing a circulation pump.  Swore it was the new pump but ended up being the breaker itself.  Replaced it and know more troubles.

Yea unfortunately I've already replaced the brand new breaker with another brand new bresker, to no avail

[gmdodt]

bump as problem is still ongoing

[Hottubguy]

Have you noticed anything weird on the top side controls?  Any moisture buildup in there?

[castletonia]

Not sure this could even be relevant, but when you replaced the breaker, was it just the breaker or the wiring too?  Is the wiring between the GFCI and the hot tub copper or aluminum? 

[gmdodt]

The breaker and wiring were both replaced despite them being brand new, but were not replaced at the exact same time. 6 gauge copper wire running from main house box to spa disconnect. 6 gauge copper wire running from hot tub disconnect thru PVC underground to hot tub.

Just did a bunch of heater measurements and they all check out in specs.. 14.5 ohms post to post on heater....16.5 amps when heating...240 volts...

Also checked all the voltages at the breaker and at the main board and everything checks out

[bud16415]

Do you have a way of checking ohms heater to housing. I don’t know the threshold for tripping the GFCI but it is very low. The heater will not blow or show any signs of being defective other than a slight trickle of leakage current. That will trip the GFCI and save the heater. If the GFCI was out of the picture the trickle that starts the cycle would burn in a carbon track and the leakage would grow larger and eventually a high current condition that would melt down the heater and blow the over current breaker.

GFCIs will detect so soon making it very hard to find the small leakage.   

[gmdodt]

From heater terminal to the outside housing of the heater ( the tube) was 0/OL when measured. Is that what you were refering to?

[bud16415]

From heater terminal to the outside housing of the heater ( the tube) was 0/OL when measured. Is that what you were refering to?

Yes , That sensitivity in a normal meter is hard to really read sometimes as it only takes 4-5 milliamps to trip and happens in 1/10 of a second.

Weeping or moisture will conduct these types of currents. 

[gmdodt]

Hmm..so no way to do further diagnosing on this? I suppose disconnecting the heater but I'd probably have to have it disconnected for more than a month to prove it's the heater since it only trips about every 2 weeks. The heater looks good. I have pictures that I posted to another thread, but no signs of moisture or burn marks. I suppose inside of the heater could be leaking? And that's really impossible to know, correct?

[bud16415]

Hmm..so no way to do further diagnosing on this? I suppose disconnecting the heater but I'd probably have to have it disconnected for more than a month to prove it's the heater since it only trips about every 2 weeks. The heater looks good. I have pictures that I posted to another thread, but no signs of moisture or burn marks. I suppose inside of the heater could be leaking? And that's really impossible to know, correct?

That’s correct to the best of my knowledge. You wont see any damage that’s what the GFCI does so well. Along with protecting you. The one place you really don’t want 240V is into the water when the water is inside a plastic container.

I’m not an expert but there should be a way to test for insulation break down using a megger tester. Here is a video.
 https://www.youtube.com/watch?v=XV6QlTwobLo

 

[bud16415]

Here is a cheap one that got an ok review on line. For 40 bucks it might be worth having.

 https://www.amazon.com/gp/product/B01AL6KZKC/ref=as_li_ss_tl?ie=UTF8&psc=1&linkCode=sl1&tag=jostonerehoto-20&linkId=412021d9a94bae68d83baf9d1308ab3b

https://www.youtube.com/watch?v=u1ei4LQAFzA

[gmdodt]

Thanks...so it seems like I'd have to remove the heater to do the testing if I get one of these. Was hoping for a test without having to drain/disassemble

[bud16415]

Thanks...so it seems like I'd have to remove the heater to do the testing if I get one of these. Was hoping for a test without having to drain/disassemble

 Not sure if you have to remove and drain. You have access to the terminals and the outside pipe. There should be no current path between the two as your zero ohms reading kind of showed. If water is playing a part then you might want the water in there. The difference is with your meter you are putting a couple volts across the insulation and with the megger you are putting 500-1000V the voltage is required as when the insulation is failing it is doing so with 240V. The extra voltage is to just help break thru the interment part of the problem.

Like I said I’m not an expert on Hot tub heaters and what voltage thresholds the insulation systems should provide. There are a lot of members here that are dealers and do frequent testing and repairs, they should know the procedure better than me. I will try and dig around a little more to see if I can find the prescribed test for these heaters. There should be a way to rule it out or in without swapping parts and waiting a month.   

[gmdodt]

Oh okay, I understand now.  Doing the same test I did but with a megger.  Makes sense.  I'll try to track someone down that has one for me to borrow.  I really appreciate all your help!