GFCI on 240 Volt Circuit? (USA)

[Nelson]

So when you install a 120V outlet in a wet area such as a bathroom or garage, you must use a GFCI outlet or breaker. Is the same true if you install a 240V outlet? If so, where would I find a 240V GFCI outlet or breaker? I've never seen one. I ask because I'm considering installing a 240V 20A outlet in my garage for lighting experiments.

-Nelson

[joe_347V]

I'm not sure about the GFCI requirements for 240V circuits but I've seen 20A double pole GFCI breakers before like this one that should work on a 240V circuit but they're not cheap.

[Vince]

It depends of your panel brand. Chances are you have either a Square D, Siemen or Federal Pioneer panel.

In a more "illegal" way, if it is illegal, is to install two single pole GFCI breakers if you can't find a double-pole model. However if you do so, each line will be independant, meaning that one line could stay live if a short happens. You could try to place a pin running in the hole of the toggles to join them together, you'd only have to test and purposely overload of short a line to see if one toggle is strong enough to trip both beakers. If it does, there will be no difference with a standard double-pole breaker!

I can make an explanation pic if it isn't totally clear LOL 

[joe_347V]

I've heard of something called a handle tie that does the same thing as the pin that Vince suggested but I'm not sure if they're code complaint.

[Nelson]

I understand exactly what you are saying, Vince! Also a good idea about the handle tie. Just to clarify, I don't really want a GFCI protected 240V outlet. I was just wondering if it is code required, and only if it is, how to provide the protection. From my research, I don't think its code required, so I'm not going to worry about it.

By the way, the panel is a Cutler-Hammer. My main panel in the house is a Square D QO load center, but the sub panels are CH.

[Vince]

Go for Siemens breakers, they are exactly the same. I think GE are also similar.

As I said, it's probably not code compliant on paper, but as long as both breakers operate at the same time, there will be no risk.

To my knowledge, if the outlet isn't closer than a certain distance from a wet location, no need to install one. That distance is 1,5m (~5 ft) in Canada, not sure for US.

[Jace the Gull]

For the USA...all garages, unfinished rooms, bathrooms and kitchen counter outlets MUST be GFCI....

I will look up to my NEC Code 2008 book and get back to you alright....

[Antstar85]

It Depends, Single outlets lets say for a big compressor or Dryer on its own breaker with absolutly nothing else on the circuit and not for general purpose use dont have to be. But if your going to be using it for experiments, I would install a GFCI breaker. They run you about $80 at a supply house as there are no 240 volt GFI outlets to my Knlowledge.

[Mike]

For the USA...all garages, unfinished rooms, bathrooms and kitchen counter outlets MUST be GFCI....

I will look up to my NEC Code 2008 book and get back to you alright....

My garage, kitchen, and unfinished parts of my basement don't use GFCIs. The kichen outlet nearest the slider door does and the bathrooms do and so does outside, but other than that all the outlets in my house are standard.

[Nelson]

I just thought of a potential problem with tying two single-pole GFCI breakers together. GFCIs work by measuring the difference in current flow between the hot and neutral wires. If I tie two single-pole GFCI breakers together and connect a 240-volt load, current will flow between the hot wires, not between hot and ground. That will cause the GFCI(s) to trip. I learned that one time when I tried to install a GFCI outlet on a three-wire circuit! The hot wire current does not always equal the neutral wire current on a three-wire circuit or on a 240 volt circuit.

So, if I did install a GFCI, it would have to be a specially designed device for 240 volt circuits like the one Joe mentioned.

[Jace the Gull]

My garage, kitchen, and unfinished parts of my basement don't use GFCIs. The kichen outlet nearest the slider door does and the bathrooms do and so does outside, but other than that all the outlets in my house are standard.

How old is your house, it may just be because it's an older house

The current codes for the newest houses and new additions, follow what is on the current codes....if you build a new room...or whatever...then follow codes...but if you replace......it is better to replace to new codes...but it is not REQUIRED..

[Mike]

My house is from 2003

[joe_347V]

My house is from November 1982 and only had a GFCI breaker controlling the garage and backyard outlets. The rest were all regular outlets.

I've since replaced all the bathroom outlets to new GFCI ones...the kitchen ones need a expensive 15A double pole breaker for each outlet since they're 15A MWBCs.

[Vince]

My house is from 1978 and there is NO GFCI outlets anywhere but in the bathroom (and it replaced the original razor outlet!). Today's average bungalow has at least 3 or 4 of them LOL.

You guys would be surprised sometimes how many code violations you can see on the field, even in new constructions!

I just thought of a potential problem with tying two single-pole GFCI breakers together. GFCIs work by measuring the difference in current flow between the hot and neutral wires. If I tie two single-pole GFCI breakers together and connect a 240-volt load, current will flow between the hot wires, not between hot and ground. That will cause the GFCI(s) to trip. I learned that one time when I tried to install a GFCI outlet on a three-wire circuit! The hot wire current does not always equal the neutral wire current on a three-wire circuit or on a 240 volt circuit.

So, if I did install a GFCI, it would have to be a specially designed device for 240 volt circuits like the one Joe mentioned.

You are totally right here, didn't think of that! XD However this trick could work with standard of AFCI breakers.

[Silverliner14B]

GFCI outlets have been required in houses in the USA since 1975. Most likely for the bathrooms first, then later required for other parts of the house.