GFI Tripping

[gmdodt]

My 2016 Vanto is still randomly tripping the GFCI every week/other week.  Pump 1 was replaced.  I pulled the board and there are no signs of any problems. Tighten all connections. Tub is wired correctly. Tried replacing the breaker itself.  Thought it was pump 2 so disconnected it and it still happened.  What else could it be!?  If it was the heater I would think it would happen more often.  Only other things are the control thermistor, LEDs, and pressure switch.  All connections for them looked good.  Losing my mind.  Been more than a year of this happening.

[SerjicalStrike]

Are there any junction boxes between the breaker and the tub?
Are the wires run underground?

You can put a meter on the tub and see if there is any amperage leaking to ground. 

You may need to check the wire from the breaker to the spa.

[gmdodt]

No junction boxes that I know of. We had the house pre-wired for a hot tub when we built it in 2011 so the wires run through the firs floor walls of the house to the backside.  They used 6 gauge from our main panel to a spa box on the back of the house. We ran 6 huge from that spa panel to the tub. The wire from the spa panel to the tub ( underground in PVC for a few feet) has already been replaced, as has the breaker. My multimeter tests of amperage indicated no leaks to ground..that I remember. Is there a certain test you have in mind?

[bud16415]

The last time you posted I suggested a test using a special tester called a megger tester to test the insulation value on the heater pass thru. I have read slight intermitting weeping or any moisture can cause an intermitting GFCI fault and could be no place close to what would progress to a melt thru if the GFCI wouldn’t be in place doing its job. The GFCI will shut it down so quickly there would be no evidence of shorting. As it is right on the boarder line to trip it would go back to working fine. A multi meter doesn’t have the current potential to see a break in the insulation.

It is the only helpful thought I have as you have run down all the other potential problems.

Sometimes romex is run thru the house but then per code if where the feed exits the house and runs to the GFCI panel outside it has to switch to conduit and romex is not allowed in conduit. So there is a J-box at that place. If the romex stays in the house and passes straight into the GFCI panel thru the back there wouldn’t be a junction point.   

[gmdodt]

Oddly enough I just found out one of my neighbors is a master electrician so I was going to contact him and see if he had the tool and could help. There may be a junction box in the house though I doubt it based on the wiring I see in the main house panel and what exits the house in the back. Just so I'm clear, you think the guy should test the connectors to the heater with the megger? I'm assuming he'd know how to do it, but if not, how does one do this test? I'm guessing all components (pumps) and lines into the tub panel can be tested with the megger too?

I'll report back when I have the electrician come over. Absent of that, I have no clue where to go from here.

[bud16415]

Your neighbor should know how to isolate the heater and megger it.

Here are a few links to look at that will give you an idea of how the test works.

Also a few links from the mikeholt site where there is a lot of intermittent hot tub GFCI fault threads.

Hope you get it figured out.

https://www.youtube.com/watch?v=XV6QlTwobLo

https://www.youtube.com/watch?v=vJlcKhc8tJo

http://forums.mikeholt.com/showthread.php?t=116446

http://forums.mikeholt.com/showthread.php?t=180181

http://forums.mikeholt.com/showthread.php?t=147080

[gmdodt]

Thanks.  Looks like id have to drain the tub so i can pull the heater to do this per the video

[bud16415]

I don’t think you will need to drain the tub just disconnect the power to the heater. The water is likely playing a part in a heater starting to short to ground. Of course stay out of the water when testing.

The way a GFCI works is by comparing current in to current out if there is an imbalance of a very tiny amount it will shut down. The imbalance happens when some part is taking a path to ground. Without GFCI the slight trickle would build and produce heat making insulation break down and then pass more current until you had a melt down or tripped the over current breaker. These things work so fast there is never an over current and they can remain marginal for a long time.

Because they are there for human projection not equipment protection they react so fast and at such a slight level a human wouldn’t even feel a shock. I would never get into a tub of water where 240v has a potential to enter the water without such a device.

I will also remind everyone to test your GFCI once a month just as it suggests inside the electrical enclosure door. It is a very good idea to do this but the only people I know that do it are people who work in the electrical field. That also goes for the 120V units in the garage, basement, bath and kitchen. 

[gmdodt]

So he just came by and he meggered the heater and both pumps, both check out.  I really don't understand anymore.  He recommended replacing the start capacitor in pump 1..but that's a brand new pump (few months).  I had already switched out capacitors in pump 2 to no avail...and those capacitors are a different size then pump 1 (ofcourse..).  Was weird to see that pump 1 capacitor is only 110v when its a 220v pump...guessing because low speed doesnt use too much to kick on?  I dont even know where to go from here.

[bud16415]

Trouble shooting an intermittent problem is one of the toughest things. You have catch it in the act and even then it isn’t something even if you were standing right there you wouldn’t get a clue unless you had a meter hooked up. In the factory we used to hook up chart recorders to equipment trying to find a problem when it happened and that’s beyond the scope at home.

Each thing you eliminate is one you can cross off the list and you just about have everything eliminated now. I know how frustrating this can be.

I think on the Vanto the ozone was an option and don’t know if you have that or not. Just in reading about problems similar to yours in trying to help you I ran across a couple where the ozone generator caused a GFCI problem. I don’t think you have mentioned that before. Just throwing out ideas.

You don’t have a circulation pump so you must have your tub set to cycle on to clean. I’m assuming this is when the trip happens. We had talked before about mounting a run light on the tub so you could see from a distance when the GFCI had tripped. You could also power a clock set to the right time and when you see the GFCI tripped the clock would stop and then you could compare the time on the clock to actual time and see if the trip lined up with the beginning of a clean cycle etc. would at least give a clue.

Your neighbor the electrician didn’t have any other ideas? I assume he did the megger at 500v?   

[gmdodt]

Yup, no ozone or circ pump.

I am assuming it happnes during filter or[/b] heat sessions too, but I cannot confirm that.

I honestly am not sure what it was set at when he was using the megger, but he did offer me to keep the tool (which i didnt but could still get) since he is retired and doesnt really ever use it.  Who knows, maybe ill retest, or test other things as people make suggestions..

Yea, it would be nice to wire a light in so that I could tell without going outside, getting shoes on, lifting the cover, etc. just to tell if it is on in the cold weather, but I just havent done it yet. 

I think what I am going to do now is use my spare baby monitor camera, sign up for a month of cloud storage and put the camera in the cabinet pointed where the LEDs are displayed.  The LEDs say if the tub is on, if its heating, etc.. Maybe if I can get more insight into when its tripping, it'll help the diagnosing.

Anywho...any other test i can do with the megger?  Like I said, he did the two pumps and heater.  He isolated each, put one end on one of the conductors and the other to a ground (not sure if it was the ground bar or what, but it was a ground..I should have paid closer attention).

[bud16415]

I would want to see the ground end clamped right to the heater unit tubes or frame. I would also disconnect the wires as to not send 500v back to the controller. The wire is rated at 600v breakthrough so the heater should be at least as high so a setting of 500v would seem fine.

I have often thought a light or buzzer if I lost power thru the GFCI would be a good thing to have. We use our tub a lot but sometimes skip even a week. Because I dose the tub manually I do get a chance to look at it most days and I hear the clean cycle run.

There is not much more than the heater and the motors that could be tested with a megger. If you are sure the GFCI is working properly and it has a test function for that. There is something in the tub that is slightly shorting to ground once in a while causing the trip. 

[gmdodt]

Well the heater has a grounding bar on it, where each pump ground comes to.  Im not sure where else you could connect the ground. Its a cylindrical tube so not many options  I suppose if i had three hands or help that I could just hold it against the tube itself.  You wouldnt want to connect it to the other pole sticking out..right (where the other conductor goes to)?  I could disconnect the green grounding cable from the heater to the main board and hook the megger to that.  The heater is metal itself obviously so I think that cable is just grounding the main board, so it shouldnt hurt to disconnect.  How he tested it still had the ground cable connected to the main board, I know that for sure since we didnt take the screw for that cable out.  Like I said, I wasnt exactly paying as close attention as I should.  I think it would probably be best for me to borrow the tool and attempt the test again.

However, on the pumps...I wouldnt disconnect the grounding wire to the heater ground bar if I were to test them, correct? Because then the pumps wouldnt be grounded.. My knowledge of electricity is pretty limited

do you think anyone of the sensors could cause a trip? They all seem to function fine and moisture to boot around them that I can see.  Only thing ive noticed is occasionally the displayed temp will not be the actual temp, but once any button is pushed, then the display temp "refreshes" and is correct.

[Jacuzzi Jim]

   last I left you, you had un-hooked pump 2 for an extended time, guessing it tripped when un-hooked?
 

    You have gone through the steps of a nuisance tripping spa more than anyone I have seen in 10 years+ on this forum.
  Pump 1 is new. Pump 2 unhooked, I assume tripped the breaker though it took awhile?     Really leaning now at the heater. For what a new element cost compared to a pump, it's a cheap option. Possible there is some kind of really minute short?  Which would be really odd, but it is cheaper then a new pump.   

[gmdodt]

correct.  the second time i unhooked pump 2 to test it, it tripped breaker.  The first time it was unhooked it went 2 months without tripping.  Heater is the next option I suppose, though it megged ok.  The only other thing is the control board...which is an expensive guess.  Id like to unhook the heater but now its fall/winter and I still think that if I purely disconnect the heater, the tub will just run 24/7 trying to heat to the set point.  If I knew what soft jumper was the heater (if there is one) i could disable to jump/heater.  Wish i had a dang caldera service manual or something

Would a universal type element do the trick? like this one on https://www.amazon.com/Replacement-Flo-Thu-Spa-Heater-Element/dp/B01M7T4E95/ref=pd_sbs_86_1?_encoding=UTF8&pd_rd_i=B01MDPRDNG&pd_rd_r=def305de-d5ac-11e8-abbe-4f1f465cc9f1&pd_rd_w=B39L7&pd_rd_wg=lu4JQ&pf_rd_i=desktop-dp-sims&pf_rd_m=ATVPDKIKX0DER&pf_rd_p=7d5d9c3c-5e01-44ac-97fd-261afd40b865&pf_rd_r=V1TT8GR9PZDXY08X6FJF&pf_rd_s=desktop-dp-sims&pf_rd_t=40701&refRID=V1TT8GR9PZDXY08X6FJF&th=1

This is the heater that is currently in the tub, just for reference -

https://www.hotspringpartshotspringfilters.com/hot-spring-watkins-parts/caldera-spa-parts/caldera-heaters-1/73994-heater-4kw?language=en&currency=USD&gclid=Cj0KCQjwkpfWBRDZARIsAAfeXarIXo3MKrZikG212Nlcqhi3tFmOyfZ_ULBT5b7ECVsKMSy3klk6-LgaAqjQEALw_wcB