Why bother with a GFI breaker here

[EricM]

This is UL approved, and requires a 2 pole GFI breaker, which seems to me is disabled upon installation.
Am I wrong here.
Take a look at the PDF file. This installation requirement seems dangerous to me!!
View attachment 2598

 

[iwire]

This is UL approved, and requires a 2 pole GFI breaker, which seems to me is disabled upon installation.

I don't see the problem, are you concerned about no neutral from breaker to unit?

If so it is not needed for the GFCI to operate, but the neutral from the breaker must be connected to the panel as shown.

 

[JohnJ0906]

I agree with Bob - the instructions state that no load neutral is used. The GFCI breaker does not require a load neutral, just that the line neutral (breaker pigtail) is connected.

My only concern with the instructions is that it shows the EGC from the spa connecting to the neutral bar in the "breaker box", not the ground bar. Of course, in many residential installations, it is one and the same.

 

[brother]

I agree with Bob - the instructions state that no load neutral is used. The GFCI breaker does not require a load neutral, just that the line neutral (breaker pigtail) is connected.

My only concern with the instructions is that it shows the EGC from the spa connecting to the neutral bar in the "breaker box", not the ground bar. Of course, in many residential installations, it is one and the same.

So how does this work, does it sense an 'imbalance' between the '2' hot legs??

 

[480sparky]

So how does this work, does it sense an 'imbalance' between the '2' hot legs??

Yes, as well as an imbalance between either hot & ground.

 

[Billy_Bob]

Yes there is a "bank teller" counting everything which goes out on one wire and making sure exactly the same comes back through the other wire. If anything is "missing" (leak to ground), then sound the alarm! (trip the circuit)

 

[quogueelectric]

I didnt see any problems.

 

[LarryFine]

So how does this work, does it sense an 'imbalance' between the '2' hot legs??

It doesn't. Imbalance may not be the best word to use when comparing 2-wire (1p) and 3-wire (2p) GFCI breakers. You could have 2, 3, or 20 wires pass through the CT donut inside the GFCI device.

As long as all of the current going to the load on the ungrounded conductor(s) is matched by the current returning on the grounded conductor(s), no voltage is developed in the sensing coil on the CT.

If any current in an ungrounded conductor returns to the source's grounded conductor (via the GES) through other than the circuit's grounded conductor, it may be passing through a person's body.

That's why a GFCI device needs a grounded system to detect accidental hot-to-earth contact. If the system is floating, the contact won't cause a current high enough to be dangerous (theoretically).

 

[quogueelectric]

This is a zero sum game.