Question on wiring a compressor ...

[Phil Harding]

I am installing a 80 gallon compressor in my garage mostly so I can spray coatings when the weather is good. I'll have to run a 220v 15 amp line from my basement shop's subpanel up to the garage. This is no big deal as I've installed 220v lines before. My question is does this type of installation require a GFI? And, if so should I look for a circuit breaker with GFI (my subpanel uses Cutler Hammer CH type breakers) or an outlet with GFI? I checked the local Menard's store where I buy my breakers and didn't find a 220v 15 amp breaker with GFI. I also haven't seen any 220v outlets with GFI. So, if GFI is required or recommended, where can I buy the necessary parts?

Thanks for the feedback.

-- Phil

[Chris Friesen]

I suspect it does not need to be GFI...but I'm in Canada and the rules are different here. Check with your local utility, or with the inspector if you're pulling a permit.

[Jim Becker]

I do not believe that a dedicated outlet for a 240v "appliance" like this needs a GFCI. If it does because of a local code or other applicable regulations, you'll need a GFCI breaker. ($$$)

[Rob Will]

A compressor starts and stops a lot so I would up the breaker to a 20 amp 2-pole and install at least 12 ga wire. Personally, I would not worry about the GFCI too much in a shop situation. Having said that, I would pay close attention to how any sub panels are bonded (not) and grounded. Make sure all connections are tight.

Rob

[Dave MacArthur]

Here is a quick rundown of the NEC that I used when wiring my garage. I also had this question, and the local inspector confirmed that I DO NOT need GFI protection on 240 volt circuits in the garage.

I used a copy of the NEC available at my city licensing section to confirm my internet research. Now, your city may have some other local restrictions, but generally you can look these up on the internet, and most cities will use the NEC as the basis for their code, and then modify. So if you read the mods online and it doesn't address this, then you're ok. Here is a link and some excerpts:
http://www.selfhelpandmore.com/homewiringusa/2002/maindwelling/attgarage/index.htm

All readily accessible receptacles in an attached garage must be GFI protected. NEC Article 210.8.A

The following exceptions can apply concerning your GFI protection of receptacles in an attached garage, if these attached garage receptacles meet the requirements of these exceptions. If a duplex receptacle is located behind a large appliance such as a refrigerator, freezer, washer, dryer etc., making the duplex receptacle “not to be readily accessible”, and if this duplex receptacle is located behind the large appliance, then the GFI protection is not required to protect that non-readily accessible receptacle that is serving that appliance and located behind that appliance. NEC Article 210.8.A.Exception.1 If a receptacle serving a large appliance is located so that it is not located behind the large appliances in a manner so that it “is readily accessible” then that receptacle that is serving that appliance but is not installed behind that appliance must be a single receptacle and not a duplex receptacle. If this receptacle serving that appliance is a single receptacle and not a duplex receptacle then this single receptacle can still be without GFCI protection. NEC Article 210.8.A..2.Exception.2 If you have a washer and a gas dryer, and the duplex receptacle is designed so that both appliances are going to be left plugged into the same duplex receptacle on a permanent basis, and this receptacle serves both the washer or dryer, and this duplex receptacle serving both appliances is locate between these two large appliances then the GFCI protection is not required, in this particular scenario as long as it is installed between the large appliances or is installed behind one of the large appliances. NEC Article 210.8.A.2.Exception.2 If you have receptacles that are installed so that they are out of reach “not readily accessible” such as located on the wall or ceiling and located above approximately 8’, then the GFCI protection is not required to serve that receptacle. NEC Article 210.8.A.2.Exception.1

If you are using a circuit that is rated 220 volts or if you are using special utilization equipment requiring specialty plugs, or a circuit that is hard wired without a receptacle, then no GFCI protection is required. “NEC Code mute” Please keep in mind that the Code requires a form of disconnect on all equipment. NEC Article 430.102.B There is an exception allowing the breaker of a panel to serve as a disconnect if that breaker is within sight. NEC Article 430.102.B Upon research, you should find the definition of “in sight” is if you can see breaker and if it is within 50’ from the breaker. NEC Article 100 definitions A receptacle may serve as a form of disconnect, {if it is not a convenience style receptacle, example would be a twist lock receptacle or a 220 volt style receptacle it may not be GFI protected} {or if it is a convenience style receptacle then it must be GFI protected}. NEC Article 210-8 and 430.109.F Code mute concerning GFI protection of the above described receptacles other than in an attached garage, detached garage, bathroom, outside receptacles, and basements.

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Sorry for the bold font etc, that is just a cut and paste from that web site, which while not 100% to be relied upon, should teach you enough to call and ask your local inspector, which you are supposed to do pre/post work for permits etc.
Good luck!

[Jim Heffner]

Phil, as I read your post it seems that what you are needing is a double pole 15 amp breaker, what that is : two breakers which are made together and use a common tie bar handle to turn them on/ off at the same time. This configuration will give the 220 volts that you need. I don't know if they are made in a GFCI type or not, but check with a good electrical supply house in your area, they can help you
with that info. Jim Heffner

[Eric Sese]

Check your manual. I have a 60g compressor with a 15 amp motor. However, the manual says to use a 30 amp breaker. My guess is that the starting amperage can peak well above 15 amps.

Eric

[Bob Herpolsheimer]

We sell 2 pole gfci breakers at the wholesale house I work at but we usually do not sell them for any motor circuits. The inrush on motor start will usually kick out the gfci. They do make a higher interrupting gfci breaker but you can add at least another $100 for that. I would say it is more important to protect your motor from an overload than to have gfci protection on the circuit.

[Phil Harding]

As usual I learn a lot from SMC members :) . I can't say thanks enough for all the input, especially Dave's research. I'll spend some time this weekend running the 12 guage wire from the basement up to the garage corner where the compressor stands. I had not originally planned to, but I think I will use a twist lock plug. I'm not going to worry about the GFCI.

Thanks again.

-- Phil