Breaker being thrown but Resistance is Good..?

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Daf-Tekno

Daf-Tekno

0
Sep 14, 2014
90
Calgary / AB
Hi TFP,

My 2008 Jacuzzi J480 was left for an extended period due to family RV activity, and when I got to it, it had leaked a little water but it was enough to take the level below the filter input.

I suspect the circ pump this ran dry.

Upon trouble shooting, I've found that I can only get the breaker to stay on if the circ pump and heater are disconnected.

If the circ pump is disconnected but the heater left in circuit, the breaker stays on for several seconds then trips. I suspect this may be because its own thermal overload protection is cutting in, and the heater may be OK.

The heater measures 9-10 ohms, which I read is the normal reading for an undamaged unit.

The circ pump measures 38-ish ohms, which is identical to the old still functioning circ pump I took off and replaced a few years ago.

I am confused.

My trouble shooting points to the circ pump being the cause of the breaker tripping. But it gives normal resistance readings, so seems to say it's OK.

How can a circ pump give normal resistance readings yet cause the main breaker to trip?

I thought it took a short circuit to throw a breaker, i.e. 0 ohms, which would confirm my suspicions that the pump is toast. But a normal resistance. ?

I'm reluctant to buy a new circ pump at $200 when my current one seems to show no electrical issues.

How can I test the circ pump to confirm it's malfunctioning and causing the breaker to trip?

Could there be something damaged on the main control circuit board?
There are 3 fuses on there, but all are intact.

I've also find that the slight leak has caused some wood mould on the base board inside the 'machine room'.
Is the best way to deal with this is to open up a number of the side skirt panels and place a fan heater in there, ventilating the area and blowing hot air over it?

Any advice would be greatly appreciated!
Thank you.
Regards,
Daf-T
 
Daf,

Welcome to TFP! Sorry to hear of your problems but you've come to the right spot. We have experts in everything.I'll see if I can ping somebody that should be more knowledgeable. @Jimrahbe @JamesW @ajw22. One or more of these folks should be able to help.

In the meantime, here are my non-expert comments: Testing resistance only in the static condition is not a complete test. Just shows that when nothing moves resistance is in range. When pump turns other things can cause the short. Also, there's normally a protection that keeps the heater from operating if there's no flow. It's possible your breaker was damaged and this is cheap to test with a replacement. If you're not thoroughly experienced and knowledgeable with disassembly of your main breaker box you should contact an electrician to do this.

Good luck!

Chris
 
Is the CB a GFCI CB? Sounds like you are getting a GFCI trip.
 
Daf,

I'm not sure that the circulation pump needs the filter input??? Anyway, if the breaker pops when the pump is connected and it does not pop when the pump is not connected, then the pump is bad.

As Chris points out, a resistance test does not prove anything is good.

I really don't see the point, but you could test the pump by itself by temporarily running power to just the pump with some kind of jumper cable...

Thanks,

Jim R.
 
Hi y'all,

Thanks for the replies.

I seem to remember disconnecting BOTH reconnecting them individually.

When the circ pump only is connected, instant breaker trip.
When the heater only is connected, breaker stays on for several seconds then trips (built in thermal protection..? I does have a thermometer probe bolted to its side which I presume is to monitor the heater, as there is a separate thermometer in the plumbing for temperature readings).

The breaker is an additional fuse box (the original one was full) and does seem to have a Test / Reset switch.
 
Thats a GFCI breaker. You have a GFCI trip due to current leakage.

Electrical GFCI - Further Reading

(Redirected from GFCI)
www.troublefreepool.com www.troublefreepool.com

You can try a process of elimination of disconnecting different things. Or bring in an electrician to look at it.
 

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BTW:
What's the average lifespan of a heater?
The tub is about 11 years old, so even though I suspect the heater isn't the cause of the breaker tripping, it may be wise to replace it anyway.

I would be kicking myself if I rebuilt the tub with the original heater, only for it to fail the middle of the Winter, which here gets to -30C (-22F..?), when draining / refilling would be incredibly difficult without it freezing solid before I could get the pumps running.
 
ajw22 said:
Thats a GFCI breaker. You have a GFCI trip due to current leakage.

Electrical GFCI - Further Reading

(Redirected from GFCI)
www.troublefreepool.com www.troublefreepool.com

You can try a process of elimination of disconnecting different things. Or bring in an electrician to look at it.
Click to expand...
I did that process of elimination, as far as I can tell, and found that the circ pump and heater were causing the breaker to trip.

With both disconnected, the breaker stays on, and the 2 main pumps run fine.
 
Daf-Tekno said:
I did that process of elimination, as far as I can tell, and found that the circ pump and heater were causing the breaker to trip.

With both disconnected, the breaker stays on, and the 2 main pumps run fine.
Click to expand...

That says there is likely some water leakage causing corrosion into their electric side. The corrosion is losing electrons to ground that the GFCI is sensing and tripping. You need to replace one or both.

Although the problem could be in the relays or electric feed to those devices. Hard to say.
 
Turn off the power and check from ground to the power connections to the pump and heater to see if there's any continuity.

It should be OL Open Line. If you get any ohm reading, that's the problem.
 
Hi y'all,

I just tested the circ pump and heater connections.

I get no continuity when checking either of the pump's or heater's power feeds in reference to earth.

I have put a small space heater inside to help dry out the dampness in the wooden floor, then I can try a mould spray.

I suspect the circ pump had a small leak, as its end is covered in dried encrustation.

I take it that with these findings, I'm fairly safe to order a new circ pump and heater..?
- Daf
 
Looks like the circ pump is the cause of your ground fault. Replace it if you can.
 

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