GFCI hot tub

[enireh]

I installed a 2 pole 50 amp GFCI breaker for a hot tub group. The display read error. I had the proper voltage at the tub. The hot tub people said since its a three wire hookup, the ground goes on the ground bar in the panel not in the neutral lug of the breaker. I changed it and the tub works. Is that breaker still protecting from shock?

 

[Dennis Alwon]

A gfci will work without the neutral connected if the tub does not require a neutral but the white wire from the breaker must be terminated on the neutral bar

 

[Jerramundi]

A gfci will work without the neutral connected if the tub does not require a neutral but the white wire from the breaker must be terminated on the neutral bar

Makes sense. With no neutral in the branch circuit, the GFCI breaker is measuring the difference between the L1 and L2 as opposed to L1, L2, and N... but if that's the case, why does the breaker neutral pig tail still need to go to the neutral bus if there's no control circuit current being pulled?

Side bar: What hot tub would NOT have a control circuit? Is there even such a thing?

 

[Jerramundi]

I installed a 2 pole 50 amp GFCI breaker for a hot tub group. The display read error. I had the proper voltage at the tub. The hot tub people said since its a three wire hookup, the ground goes on the ground bar in the panel not in the neutral lug of the breaker. I changed it and the tub works. Is that breaker still protecting from shock?

As far as I'm aware, the GFCI breaker itself is NOT utilizing the ground / wire-type EGC in protection of the circuit. The wire type EGC is there to clear the fault. The GFCI breaker itself is measuring the current on L1, L2, and N (if you have it) for protection.

 

[Dennis Alwon]

Makes sense. With no neutral in the branch circuit, the GFCI breaker is measuring the difference between the L1 and L2 as opposed to L1, L2, and N... but if that's the case, why does the breaker neutral pig tail still need to go to the neutral bus if there's no control circuit current being pulled?

Side bar: What hot tub would NOT have a control circuit? Is there even such a thing?

The neutral is needed for the electronics inside the gfci.

Yes there are many tubs that are straight 240V. Transformers can do lots of things...LOL

 

[Dennis Alwon]

As far as I'm aware, the GFCI breaker does NOT utilize the ground / wire-type EGC in protection of the circuit. The wire type EGC is there to clear the fault. The GFCI breaker itself is measuring the current on L1, L2, and N (if you have it) for protection.

View attachment 2553836

That is correct. That is why a gfci works even when a receptacle does not have an equipment grounding conductor.

 

[Jerramundi]

The neutral is needed for the electronics inside the gfci.

Ah, that makes sense.

 

[Jerramundi]

Transformers can do lots of things...LOL

So would this be like.. a transformer internal to the hot tub that has a secondary winding with a center tap that allows for the 120V control circuit?

 

[Jerramundi]

Is that breaker still protecting from shock?

Do you know "the thumb rule" for determining the direction of the magnetic flux? It should help you understand how this breaker is still providing protection.

 

[hillbilly1]

So would this be like.. a transformer internal to the hot tub that has a secondary winding with a center tap that allows for the 120V control circuit?

Controls would be 24 volt, maybe even less.