Will a 2p 20amp gfci breaker still work as intended in a sub panel with no neutral?

[serenity5807.wt]

I'm installing a 20amp 240v roof heat system that requires a gfci breaker. I had a 2 pole 40amp feeder to outdoor disconnect for ac condensor originally. I eliminated disconnect switch and made it an out door subpanel to feed roof heat and condensor. Since no neutral was ran for condensor originally, do I have to run a new feed from panel just for gfci breaker? Or will it still function properly without it

 

[ptonsparky]

I believe you want GFI protection for eguipment, not GFCI protection for personnel. The neutral is required for GFCI. IDK about GFI.

 

[Dennis Alwon]

I don't know about GFP either but I suspect it needs a neutral also

 

[GoldDigger]

It is possible to design a GFCI breaker that operates from 240 line to line with no neutral, but if would require a different circuit board than the one used in a single pole 120 or 2 pole 120-0-120 breaker. For that business reason there may not be any on the market.

 

[JFletcher]

We recently installed a 2p 50A GFCI breaker for a spa that did not have a neutral from the sub-panel to the spa. It did have 4 wires from the main panel to the sub panel. You need a line side neutral, so just put the GFCI breaker in the main panel. Done.

 

[templdl]

If you don't have as my line to neutral load then no neutral s required except....to my understanding the neutral is used in order to use the test pushbutton to test the breaker.

 

[GoldDigger]

If you don't have as my line to neutral load then no neutral s required except....to my understanding the neutral is used in order to use the test pushbutton to test the breaker.

Your understanding is incorrect. The electronics is powered from one line to the line side neutral in breakers with a neutral pigtail or neutral bus stab.
Just as with the 120V GFCI receptacle, the TEST button only needs access to two wires which pass through the differential coil. In a 2P breaker the neutral could be one of those, but it is not necessary.
It is interesting to note that if you lose the unlucky phase of a 2P 220/240 breaker you can still have power to the other phase *without GFCI protection*.