Spa Circuit Breaker tripping

Hello Sapper,

"I'm in Australia so the system is 240V AC Single phase 50Hz two wire & earth".

As far as I am aware, your system in the land of Oz, is MEN = Multiple Earthed Neutral, same as New Zealand and other enlightened Countries.

So...Have you checked the motor current under load?

The Spa Circuit Breaker may be faulty - Replace

The RCD sensing relay in the Spa unit may be faulty - Replace

Did you "Megger" = Insulation Test the Motor windings?

If all the above are Tested and satisfactory, put a milliameter into the Earth leg at the motor, measure earth current without motor running, then with motor running. There should be less than 1mA leakage in a good motor.

Sometimes a motor develops a "rust spike" from inside the housing, puncturing the winding wire insulation - when you power on,the breaker of fuse blows, the rust spike clears a little, then on the re-power, repeats that process.

If the motor is capacitor start, the capacitor may be faulty - internal breakdown, which clears for a "short" (lovely word there) time, and repeats as per the "rust spike" above.

It is possible, because this type of installation has high humidity levels, that some condensation exists inside the Spa Controller box and/or the Motor.

You may find the centrifugal switch on the motor has damaged insulation, a carbon track through the fibre, or a screw loose, giving odd results.

That will do for a start, after the above may prove helpful....

SparkStation,

When I bench tested the motor I loaded up the motor with a jeryrigged friction brake on the shaft (i.e. two bit of wood wired together at one end and hand grip on the other using the bench to stop the whole thing rotating).

The current did not get higher than the rating plate.

I did replace the breaker, but not the RCD.

I'll have to get hold of a megger for the windings or get someone who knows more about it to pull it apart and give it once over, when I pull it out again.

I probably should megger the cable from said spa to the board...hadn't though of that...

It could be 2-3 weeks before I get back to this as the problem Spa is on the other side of Sydney..

Thanks for the assist.

Sapper.

Hello again Sapper,

When you "Megger" = Insulation test, remember to disconnect anything with semiconductors in it, or it will be expensive.

"It could be 2-3 weeks before I get back to this as the problem Spa is on the other side of Sydney.."

Are you walking there and back, carrying your toolbox in one hand, the motor in the other hand ?

Happy Christmas, and we look forward to....

In addition to all the good and valuable advice above, consider the possibility of a live-to-earth or a neutral-to-earth fault within the cable that supplies the spa, downstream of the breaker. Ditch both ends of the supply cable and test it on ohms. If the core-to-core resistance is less than a few hundreds of KΩ, then it may be a fault in the cable, in which case try temporarily bypassing the suspect cable and see if the fault stays or goes.

Another possibility is a neutral-to-earth fault elsewhere on the installation, whereby the increased current in the neutral is sufficient to produce imbalance on other circuits. Recent experience: a high load on an oven circuit caused a whole house 100mA RCD breaker to trip where the oven circuit 30mA RCD breaker did not. The fault was eventually traced to rodent damage to a cable on a separate 6A lighting circuit fed from the same distribution board; its neutral-to-earth path was causing the trip when the oven load went up. Once the cable was isolated, the trip did not recur.

Needless to say (?) do NOT simply change the RCD breaker for one without RCD protection just to get the damn thing going again!

Are there any heater elements or lights that are part of this spa? Are there any controls on the side walls or are they remote to the unit?

Hi Sapper,

If you had changed new Circuit Breaker without RCD and It didn't trip.

It is ok, but please earth all or Spa's parts for safety first.

And now I want to go to Spa and massage .

You know, this is a long shot, but did one of these "rude young men" perhaps wire hot to neutral somewhere in the circuit?

Also, have any of the strain reliefs at the junction boxes or any of the hardware that secure the wire to the frames pierced the insulation? I had that happen in a lighting circuit...

It sounds like you might have checked the latter, but hey, you never know...

Good luck!

Hi Sapper....

If you ran you motor on the bench and it was ok...well then...it should be ok. You could have something shorting or grounding between the motor control and the motor.

If you can come up with a circuit diagram...see what else is on that circuit...like heaters. Usually a heater element justs poops out open but the metal clad ones can certainly short to the case.

Does the motor trip out the circuit instantly or is there time involved? Locked rotor will trip you out fast but not as fast as a true fault.

You could very well just have a jacked up pump. Nice big furball stuck in it or a bushing gone.

First things first...has this spa ever worked? Was this a DIY homeowner installed project? What size breaker is being used? What is the inrush current on the motor?

You are on the right track, test parts separately. If possible disconnect the heater section and run spa without it (We would presume you have a heater element in that spa to heat the water). Check that over for short circuits. Is your circuit breaker a built - in GFI type , if so maybe thats it. Check whole system a piece at a time and also look for frayed wiring, chaffed wiring, etc. Theres a certain vibration in those spas that can over time wear through wires if they are not places well and insulated well and also clamped out of the way.

Its Christmas

I got to put in my 2cents worth (Canadian).

GFCI can be a pain in a Spa application .People use the perfumed oils to make the water a "heavenly " smell . The problem becomes if the spa is in enclosed area the steam also contains the water soluble oil mixture and this seems to put a film every where on the spas circuit board the water piping anything that can give a ground path and that is all it takes to trip a GFCI so maybe start a wipe or a clean spray of any semi exposed piping circuit boards use approved electrical component spray . Maybe you can find it quickly I had a spot on a drain valve thru a coupling that just looked a little dusty. Happy Spaing and have a Happy New Year .

Just another angle as to what could be tripping the breaker........

I don't know all your particulars, however I have a spa and exactly the same thing was happening. Went through all the components and found it to be the heater. I had shut the spa down for the winter and when I went to restart it, it did exactly the same thing your are discribing, tripped the breaker as soon as I tried to start it.

Turned out the heater element was shorted inside the heater tube. I just ordered a new element and replaced it inside the heater tube and all is well! Good luck.