I have a hot tub fed with 240V from a cutoff breaker mounted outside the house. It was installed in 2001. It is a dedicated 50A 2-pole GFCI breaker (Square D).

The spa has:
1 circulating pump that's always on
1 heating element, which is on when required to hold temp
1 blower motor for bubbles only
2 jet pumps, one of which is a two speed, the other single speed

The breaker will trip after 5-10 minutes of using the tub with the 2-speed jet pump on high during human use.

During non-use, the circulating pump is always on and the heater is on when needed to hold water temp. 4 times a day (every 6 hours), the 2-speed pump comes on low for an hour in addition to the aforementioned circulating pump and heater. One of those 4 times, in addition to all that, the blower comes on for about a minute. All of this is normal 24 hour cycling of the spa.

All the above non-use cycles occur WITHOUT tripping the breaker. It's only when the spa is used manually and the 2-speed pump is turned on high that the breaker will trip after 5-10 minutes initially. After reset, it will trip more quickly (but not immediately) after less than a minute.

Two questions:
- How can I tell if the breaker is tripping due to a fault or due to an overload?
- can a breaker (or its GFCI component) go bad and if so, are my symptoms indicative of that?

I would simply replace the breaker, except it costs $100 and would rather narrow the problem down before trying that. I know I could (for testing/diagnostic purposes only) replace the breaker with a cheaper non-GFCI version for about $10. If that breaker tripped, it would indicate an overload problem. But if that breaker didn't trip, it wouldn't really help eliminate a bad overload breaker and/or I still might have a latent ground fault (that for some reason only comes after turning the pump on high).

Besides answering the two questions above, does anyone have any words of wisdom or suggestions?

Thanks,
-Jim

 

You could use an ampclamp meter on the motor and see what the load is on the motor,what is the manual cycle you mentioned?

 

Thanks...

Yes, I could measure the current draw with an ampclamp...but the trouble would be catching it since I never know when it might happen (I don't have a peak-reading meter).

All I meant by "manual" was using it by getting in the tub and setting the jets to their desired settings. The 2-speed jet pump is never run on high speed during unattended cycles...only if someone is in the tub and sets it to high.

 

Welcome to the forums.

This is when you need to be watching the current demand for the entire spa. If it were an over current problem it should be high when the 2 speed pump is on high.

 

Thank you for the reply.

Instead of "5-10 minutes", I should have said a less specific "sometime later" since it's not that predictable. For example, I just ran all pumps (maximum current draw) for 25 minutes with no breaker pop.

 

Is that what the manual cycle would do?

 

My initial question is whether I can tell (from looking at the popped breaker) whether it popped due to a ground fault (which could be from a leak I can't see), or an overload (whether it was real or breaker-perceived).

 

Don't get hung up on the phrase "manual cycle". All I mean by that is someone is setting the pumps manually as one would when they were using the tub. It's not a 'cycle', it's just someone using the tub.

 

Got it! Have you checked the wiring go to the pumps for chafed conductors,I have never seen a GFCI breaker that would indicate if it tripped because of ground fault or overload or a short.
Geo

 

Your heater is failing.
To prove it, disconnect the wires going to heater and see if the breaker stays on.
Of course the wire will be live so tape the ends.

 

What was the current reading ?

 

Geochurchi...thanks. I checked the wires. Although all looked good, I did find one of the heater wires crossing a ground lug and thought (since it was very damp and rainy) that perhaps the GFCI may have senses a small leakage through the insulation (similar to damp spark plug wires in a car) so I wrapped it in electrical tape and moved it away. I know it might be a long shot, but can't hurt.

 

Pjmax....the current was 40A.

 

Electromen...hmmm, I will try that today if the weather allows. I'm curious, though. You sound fairly sure and perhaps have seen this before. How would a heater element be failing and cause this? Since it's just a resistive element, it seems it would just open up and stop pulling current.

 

I would think it would be like an element in a water,when they fail it trips the breaker,short to ground on one side.

 

It's pretty hard to blame the heating element. They are a constant source of problems and when they start going bad the resistive coil leaks to or touches ground causing the GFI to trip.

BUT... that short should be occurring at times other then when using the spa in manual mode or with the blower on and it's not.

 

The past three Spas I was sent to troubleshoot for tripping the breaker have been heating elements failing. The last one I didn't even go look at it. I told my friend what it was and that was it.
They were all older spas.

 

I agree..... the heating element is the number #1 cause of a GFI breaker trip.

But we're being told it ONLY trips when the pump is on high. That is not common.

At this point it may be advisable to replace the heating element and if the problem is not repaired.... you have a spare heater.

 

Thanks everyone. The weather's been and will continue to hover just above zero degrees here for a while. Unfortunately (or fortunately - depending on your point of view) I've cycled the pumps in various speeds and times since my last post and it's not tripped the breaker.

Pjmax...you noted if it were the element, why would it only fail on 'high'. Good question. The only possible explanation might be it only very intermittently shorts to ground and only on high because that's when there is maximum flow and pressure in the heating element housing. Perhaps the excessive rush of water and pressure at that time aggregates the fault somehow.

The good news is that the spa seems to be maintaining itself without incident, so I can worry a little less about it freezing up until the weather gets a little warmer. At that time (assuming no failures in the interim), I'll stress it again manually to try to get it to fail. If it doesn't, I'll wait til it does and go from there.

Thanks again!
-Jim
(BTW, I just now noticed I posted this in the wrong forum. I was intending to post in the electrical wiring forum but because I am on a tablet...perhaps my fat fingers clicked the wrong link. Sorry).

 

It actually should have been in the spa forum but now it's in electrical.

Thank you for posting that because I was thinking the same thing. There could be excessive pressure causing the heating element casing to contract.

If that is the case.... the element is not long for this world. If you're in an area with freeze issues.... get a spare.