Slight shock/tingling using spa touchpad

[chapmanla]

I have an above ground Coast spa with a touchscreen control pad.  Recently I felt a tingling sensation when in the spa and touching the touchscreen (similar to small battery shock).   There is a 50 amp GFCI breaker serving the spa which has never tripped on its own (even when reproducing the tingling sensation from outside of the spa).  The test button on the breaker seems to work fine (it alway trips the breaker).  There is also a software-based GFCI test utility accessible through the spa's touchpad that can be used to test the breaker and it tests fine.  The shocking doesn't seem to be correlated to the running of any pump, heater or lights.  When the touchpad is wet, touching any active button area when also touching the spa water produces the shock.

Needless to say, I've stopped using the spa and called my spa installer.  He is insistent that any shocking like this should immediately trip the breaker and that replacing the GFCI breaker may correct everything.  Even though I wasn't sure that the GFCI is defective, I just had the electrician come out and replace it.  He and I just confirmed that nothing has changed (still shocking and no breaker trip). We have inspected all of the AC wiring and everything seems fine.  

While I agree in theory that and noticeable current leakage should trip the breaker, I'm wondering if the amperage generated by the touchscreen is below the 5mA current leakage necessary to trip the breaker. 

Given the the spa installer was convinced that it was a GFCI breaker issue, any insights from the community would be greatly appreciated I discuss next steps with him.  

Thanks.

 

 

[RDspaguy]

The control pad operates at low voltage on the load side of the low voltage transformer and has no physical connection to the gfci, so cannot cause it to trip. You need a new controller, as your has lost it's waterproofing. I am surprised that neither of them knew this.

[chapmanla]

Thanks.  I had suspected that the DC-powered controller might be isolated from the GFCI detection circuitry.  Just so that I can respond to the installer, is the following statement correct?

"The control pad is powered through a low voltage transformer.  Even if there is a small current leak from the control pad, the amperage draw difference through the transformer isn't sufficient to trip the breaker (i.e., a big enough current leak would be detectable but not this level of leak)"

Thanks again for responding.

 

[RDspaguy]

No. It wouldn't matter if it were 100 amps. The low voltage is not part of the gfci circuit. It is isolated by a transformer, which has no physical connection to the gfci circuit on the load (low voltage) side. A transformer uses electromagnetism to produce voltage. It also is not DC, but 12-24 volt AC depending on the control system.