Hot tub tripping GFI Breaker

[Riograndeelectric]

lat week I was at a customer house to repair the Wiring on there hot tub. Hot tub was manufacture in 1992.
The original installation was made using EMT laid directly on the ground and no GFI breaker.
I installed new PVC and a GFI breaker re pulled in 4# thhn Copper conductors. nameplate calls for a 40A circuit max.
The home owner called me to day to say that when the heater is turned on the GFI trips immediately.

I amped out the Neutral and ground wire together and am reading 8.22 MA . the hot tub runs fine with out the heater.
any idea on what is causing the Heater to trip.

 

[Dennis Alwon]

My guess is the element is shot. Did you ohm the element to ground on each side?

 

[Riograndeelectric]

My guess is the element is shot. Did you ohm the element to ground on each side?

I did not even think of that any ideas what type of reading I should be looking for?

thanks for the suggestion.
I will go back and ohm the heater out.

 

[Sierrasparky]

Sound like a bad element.
I was wondering why you pulled #4, Was it a long run?

 

[480sparky]

Try disconnecting the leads to the element itself. If the GFCI doesn't trip, you've isolated the problem.

 

[jcole]

I did not even think of that any ideas what type of reading I should be looking for?

thanks for the suggestion.
I will go back and ohm the heater out.

You should read no continuity to ground on each terminal of the element. Make sure you unhook one or both of the wires on the element before you test.

I agree with the others. More than likely a bad element

 

[Rewire]

99% probability its a bad element I change them several times a year on older tubs.

 

[Riograndeelectric]

Sound like a bad element.
I was wondering why you pulled #4, Was it a long run?

sorry for the typo. I meant to say re pulled #8 thhn

 

[goldstar]

I agree with the others, it's propbably a bad element. However, how can you be sure it's tripping the GFI feature ? As an experiment try temporarily replacing the GFI breaker with a std. breaker and see if it trips on overload. If it does then you'll know you have a shorted element. If it runs properly then there is a GFI problem within the heater and has to be replaced anyway. From what I remember, GFI breakers and receptacles are set to trip at 5 mills but I could be wrong. Just my 2 cents worth

 

[mxslick]

I agree with the others, it's propbably a bad element. However, how can you be sure it's tripping the GFI feature ? As an experiment try temporarily replacing the GFI breaker with a std. breaker and see if it trips on overload. If it does then you'll know you have a shorted element. If it runs properly then there is a GFI problem within the heater and has to be replaced anyway. From what I remember, GFI breakers and receptacles are set to trip at 5 mills but I could be wrong. Just my 2 cents worth

Why bother? The OP has already found over 5ma of leakage..

I amped out the Neutral and ground wire together and am reading 8.22 MA

Replace the heater element and check all the wiring internally in the tub for damage. Also make sure the thermostat and high temperature cutoff (usually mounted on the heater's housing) aren't wet or going bad either.

 

[Riograndeelectric]

I agree with the others, it's propbably a bad element. However, how can you be sure it's tripping the GFI feature ? As an experiment try temporarily replacing the GFI breaker with a std. breaker and see if it trips on overload. If it does then you'll know you have a shorted element. If it runs properly then there is a GFI problem within the heater and has to be replaced anyway. From what I remember, GFI breakers and receptacles are set to trip at 5 mills but I could be wrong. Just my 2 cents worth

tub was originally tied to a non GFI Breaker. when I repaired the wiring installation I changed to a GFI breaker. prior to installing the GFI breaker the tub ran fine a 2 pole 40amp non GFI breaker.
I ohmed out the heater and found that there is a high restive short to ground on one side of the element . I made sure to disconnect the heater from the tub first before ohming it out.

Thanks fro all of your help.
I informed Home owner to have heater replaced.
I don't like repairing or replacing hot tub internal parts and leave this up to the hot tub repair guys . I do come back and inspect there work when they are finished to make sure the repair was not jerry rigged.

 

[MF Dagger]

I always thought it was "jury rigged". I hear "jerry rigged" all the time and could never figure out where it came from.

 

[c2500]

I always thought it was "jury rigged". I hear "jerry rigged" all the time and could never figure out where it came from.

Jury, is the cousin of Jerry, twice removed.

 

[hurk27]

I find this all the time around here, home owner shuts down the tub to clean, and empties it out, then after cleaning starts filling it, and turns on the power. not realizing they default to heater operation as soon as the power is restored, this is so they wont freeze up in the winter.

 

[-=PEAKABOO=-]

I agree with others. I bet it is the heater element shorted to ground.
I have seen this on many of occasions. I once had one that was an older tub (non GFI) and it was tripping the 50 amp breaker feeding the tub. The homeowner had been using the tub in the hotter months with it like this for years.

 

[-=PEAKABOO=-]

I always thought it was "jury rigged". I hear "jerry rigged" all the time and could never figure out where it came from.

I usually here it called something else.