2002 Sundance Cameo started tripping GFI every few days

[doronby]

We have a 2002 Sundance Cameo that stated to trip the 240 GFI every few days.
 
Since I have a 'time of use' electricity service, the spa is in 'Economy mode' so it only heats up during the cleaning cycles.
 
I set the cleaning cycles to run during the night (cheaper electricity) so that when I get into the spa ( ~6 am) the spa is at the desired temp (~100f)
 
The GFI trips sometimes during the night... every few days.....
 
It Never trips while using the spa with all 4 consumers on (circulating pump, big motor, the two speed pump and air blower going)
 
Things I did so far.
 
1) Ozone generator was >5 years old so I replace it. ---> No help
 
2) Circulating pump was 13 years old  so I replaced it with a more efficient one --> No help
 
3) Heater element was 13 years old so I replaced it --> No help
 
GFI test button in the main panel work well
 
--- H E L P -- What should I do next ?

[Jacuzzi Jim]

At this point I am guessing pump 1.  Intermittent tripping when it's running on low speed for the filter cycle.   You could unplug the pump run the spa for a few days, if it doesn't trip plug it back in and see what happens.  If it does trip then it might be pump 2 when it goes into it's purge cycle.   

  Intermittent tripping is a pain! 

[doronby]

Is there any other way to test the pumps ? (I own a decent Fluke multimeter...)
Sometimes the spa runs for a couple of weeks before it trip.

Thanks
-D

P.S. what exactly happens during the 'Cycles'. Pump1 ? Pump2 ? Air blower ? Heater ? Circulating pump ?

[mjb]

If your spa has an ozone generator, disconnect it and see what happens.
It's not uncommon for an older system to create problems.

[doronby]

Ozone generator was replaced a few days ago...

[Jacuzzi Jim]

 In economy mode the spa will only heat during a filter cycle, pump one will run on low speed and the circ pump will run the duration of the filter cycle one two or three hours, what ever you set it for.   A purge cycle will run pump one on high for 20 or 30 seconds, then pump two for the same and shut down.   

[Nessuno]

I agree with Jacuzzi Jim. Try unplugging one thing at a time to see if it keeps tripping. You could start with the ozonator and air pump since you don't really need those to enjoy the tub. My 2001 Cameo seemed sensitive to thunderstorms rolling through. I always check to make sure it is running after a major lighting storm.

I also had an issue where the heater had a slow leak and was dripping onto the circulation pump which sits directly below it. This may have been the issue for some of my GFI trips, but I never confirmed that.

[doronby]

There has to be a better way to test these devices as some times the spa runs for 10-14 days before a 'GFI Trip'.

This is a new phenomena as this spa ran for 12 years without a single 'un-explained' GFI Trip....

I now have new Circulation pump, Ozone, heater (all 3 replaced in the last 2 weeks to no avail)

-D

[Jacuzzi Jim]

 Like I said nuisance tripping is a PIA.   Process of elimination works.

[Wannatub]

Admittedly going way out on a limb here, but it is at least conceivable that a 13 year old breaker itself could be getting tired. Or perhaps even less likely, connections in side the box or spa could have somehow become susceptible to even something as unexpected as atmospheric moisture causing an intermittent fault.   Low probability I know, but it shouldn't cost anything to look.

[Nessuno]

I did a quick google on "ghost GFI trips" and came up with the following. You might find them interesting:

http://www.fluke.com/fluke/uses/comunidad/fluke-news-plus/articlecategories/grounding/chasing-ghost-trips

http://www.thepondshoppe.com/pond-maintenance/gfci-tripping.aspx

[Nessuno]

I was looking at some more google results. There's a lot of useful info out there on why GFIs might trip randomly. You can use a clamp meter to see if there is any leakage current among the different components. Water and bad insulation on the wires are high on the list for causing ghost trips.

[doronby]

Just for fun I measured 'ground to black' and 'ground to white' on the Ozone unit I removed last week and I got 6.5  and 8.2 megohms...

What is considered a 'bad' value that is going to trip my 60Amp 240v GFI ?
(to get '5mA' current leak do we not need less then 50 Kohms...)

-D

[doronby]

After running flawlessly since my last post (15 days ago) , GFI tripped again last night...

[Jacuzzi Jim]

After running flawlessly since my last post (15 days ago) , GFI tripped again last night...

  Well now you know it's not the ozonator if it was un-plugged.   Now try un-plugging pump 1 and wait till it trips, if it does it's not that one either.