240v GFCI work with no neutral ??

[bassphisher]

Will all 240v GFCI breakers work without a neutral.
I inspected a hot tub the other day that only required 2 phases and a ground to operate.I looked at the installation manual and in it was a wiring diagram that showed the neutral from the panel brought out to the breaker (no bonding)on the outside of the house and then from the breaker to the hot tub 2 phases and the ground.
Can I assume that all 240v GFCI breakers will operate like this or does it have to be a special breaker.The manual does not address this.

 

[haskindm]

Re: 240v GFCI work with no neutral ??

The breaker will have a neutral wire that connects to the panel neutral, but I have not seen a 240-volt GFCI breaker that required a neutral from the breaker to the load.

 

[electricman2]

Re: 240v GFCI work with no neutral ??

2pole GFCI breakers do not require a neutral connection on the load side, only on the line side to operate the electronics. It will work just fine.

 

[rick hart]

Re: 240v GFCI work with no neutral ??

I'm not convinced that a GFCI 2 pole breaker will even work with a neutral load.

Wouldn't the voltage imbalance look like a ground fault?

 

[bassphisher]

Re: 240v GFCI work with no neutral ??

Sorry I looked at the wiring diagram wrong.Their are two diagrams,I thought that one used a neutral.I was wrong

 

[hurk27]

Re: 240v GFCI work with no neutral ??

By Rick: I'm not convinced that a GFCI 2 pole breaker will even work with a neutral load.

If the two pole breaker used has a load side neutral, it will work!
The operation of a GFCI is very simple, We use the same principle to cancel out magnetic fields when we run all conductors of a circuit in the same raceway. In side the GFCI breaker there is a current coil which all intended current carrying conductors pass through, as long as all the current that the circuit is using passes through this coil there will be no current induced into the coil to trip the relay and shut off power, but if any current (5ma or more) finds another path (IE: your body, Earth Etc...) and flows back to source on it then the canceling out effect will cause current to flow in the current coil which will cause the current relay to trip the breaker.

This is why you must wire a two pole GFCI breaker that is intended to serve both 120 and 240 volt loads with a neutral from the load neutral terminal to the load as it must flow through the current coil of the breaker.

Here is a good article on GFCI's and how they work:
Click "HERE"

 

[bassphisher]

Re: 240v GFCI work with no neutral ??

Sun Dance Instruction ManualCheck out the instruction manual for this spa.In the wiring diagram it shows a load neutral connection on the breaker not used.Thanks for your info.I am going to do some more reshearch.I have not had a chance to read your article yet.
Paul

 

[al hildenbrand]

Re: 240v GFCI work with no neutral ??

John,

I looked at section 17, page 46, of the manual, diagrams A & B. That looks quite in order.

As noted in the posts above:

Two pole GFI breakers require a line side neutral (in order for the breaker electronics to work). Load with, or without, neutrals may be connected to the load side of the GFI breaker.