Wiring a garage

[joe.joesmith4j]

Hi,

I'm starting a project to wire my garage and I have a couple of questions. The breaker panel is in the garage (front right corner). My plan is to run EMT on the wall around the three sides of the garage. I will also have conduit running up one wall and across a joist for an outlet for a garage door opener (GDO).

All of the outlets will be 20 amp. All of the wire will be #12 stranded. There will be approximately 3 receptacles per circuit except for the GDO where there will be only one.

[FYI...I have two lights in the garage on an existing circuit.]

My plan is to install three new circuit breakers in the panel. 1 is for the GDO and the other 2 will be for the wall outlets.

Questions:

1. Is it better to use a t-connector in the EMT and then run conduit down to a work box? Or would you pass the wires (for other circuits) thru the work box?

1. Is it better to use a GFCI circuit breaker and regular receptacles? Or should I use a regular breaker and GFCI receptacles? Given the # of receptacles per circuit, the cost is about the same.

Comments? Suggestions?

TIA...Joe

[Tony Hwang]

Hi, I wouldn't use GFCI breaker if it trips you lose the whole string on it. I'd rather use receptacles.

[BobK207]

Joe-

BTDT ( a couple of times for a "from scratch" garage installation) so I'll share my mistakes so you can avoid them

The first time around I used a 4O box as the "T connector" & ran EMT down to 4S boxes that I used for a double duplex installation every 4 ft or so.....why I did it this way I cannot tell you....it was ~25 years I don't remember but I guess it seemed like a good idea at the time.

In hindsight this seems like a lot of un-necessary extra EMT & wire

The next installation I did (helping a friend with a from scratch garage wiring) , we set 4S boxes where he wanted the double duplexs to be & daisey chained the duplexes on two independent circuits feed by the load side of GFI outlets.

I think I prefer multiple GFI receptacles instead of feeding regular receptacle from the load side of a single GFI receptacle or a GFI breaker......multiple GFI receptacles allow you determine the location of the fault easier plus if you put a fridge on the circuit sometimes they trip GFI's.

If you install a LOT of GFI receptacles it could get a little expensive

Here's where I caused myself a little grief.....make sure you check your conduit fill (wire type, number of conductors & conduit size dependent) & your box fills (wire size, box size & number of devices)

Unless you have a reason not to, I would consider 3/4 EMT / flex and BIG (& deep) boxes with plaster rings...easier to get everything to fit & easier to work in.

cheers

[Ashton Crusher]

In my house, which was wired by electricians, inspected by city, etc when new, they only use one GFI outlet on each protected circuit, the rest of the outlets are able to run off the one GFI. I have not checked but my guess is that the outlet with the GFI is the first one off the breaker and the rest of the outlets are run thru that first one. Unless your local code says you can't do it that way you would save a lot of money on GFIs by using that wiring method.

[David Nebenzahl]

Ashton Crusher spake thus:

That's true; the tradeoff, as someone else mentioned, is that this means if the any outlet on that circuit trips, the whole circuit (downstream of the GFCI outlet) goes out, instead of just the one.

[RBM]

The least expensive method would be for the first outlet of each circuit to be a GFCI receptacle protecting the two outlets downstream of it. Keep in mind the ceiling outlet should be single, not duplex and not GFCI protected and any outlets that will be used for stationary appliances, like freezers and refrigerators should not be GFCI protected

[Pete C.]

My shop is wired similarly. I ran EMT along the top of the walls mounted to Unistrut at every other stud location. Each run has two T fittings and then a final bend so each run serves three drops. Each drop (not counting a few 240V feeds) runs down to a 4" square box containing a 20A GFCI outlet and matching Decora style 20A outlet providing a fully GFCI'd quad at each drop location. Every drop is a separate circuit, so three circuits per conduit run.

Using the T fittings makes things a bit easier to pull and neater, particularly with the horizontal runs being located at the 7'-8' level and the outlets at the 4' level.

A GFCI outlet provides protection to everything wired downstream of it, you do not need individual GFCI outlets for every outlet. A GFCI outlet costs around 1/4 - 1/3 the price of a GFCI breaker and both provide essentially the same protection so there isn't a whole lot of reason to use GFCI breakers unless you like spending money.

Pete C.

[Beachcomber]

The electricians who wired my house carried this principal to absurd lengths when they wired my bathroom outlet downstream of the garage position GFI. The least amount of GFI's that they could get away with was two and they are placed in really inconvenient locations.

I can see why they did it that way though. My house is in a subdivision where all the houses were wired that way and someone saved something like $500 bucks during the construction period by doing the minimum.

I wish I would have been there during construction. I would have had the builder give the electricians extra money to install more GFI's.

Beachcomber

[AZ Nomad]

It's easy enough to correct. You can add additional GFIs anywhere in the chain; then you move the wires at the previous GFI to supply power from the previous GFI's input instead of it's output.

[MRC]

Check your local code, but when I finished my garage, I found that all outlets needed to be GFCI protected unless they were used for some sort of dedicated appliance (such as a fridge).

[hallerb]

thats pretty much the case everywhere.

non proitected for freezer or washing machine must be singles ONLY

[joe.joesmith4j]

Thanks for all the great answers. A couple of clarifications on my end.

I will be using 3/4" EMT and 4" metal workboxes. The typical workbox will have one duplex receptacle in the center. The last workbox on one of the circuits will be a quad.

As mentioned before, one of the circuits is for a GDO. The other two circuits will be used for power tools and other garage/workshop equipment. There are no plans for a refrig, washer, dryer or similar equipment. My wife wants less junk in the garage, not more :)

Sounds like the best way for me to go is GFCI at each receptacle. Cost wise, that's not a huge difference for me with respect to the overall project cost.

FYI...I will be having an electrician/friend work on this project with me. I'm trying to do the leg work, etc., but when it comes to touching the panel, that's for him to do. I have asked him some of these questions, but I can't call him every two minutes when a new thought pops up in my head. Plus, he was kind enough to split the project with me -- most electricians wouldn't do this -- so I'm trying to be as knowledgeable as I can.

Thanks again...Joe

[joe.joesmith4j]

RBM,

I'm curious to know why you think the ceiling outlet for a GDO shouldn't be GFCI? I've read elsewhere on the Internet that there are good reasons to have GFCI for a GDO. One such reason had to do with lightning strikes.

Also, why do you say a single outlet vs. duplex for the ceiling? Is this to ensure that nothing else gets plugged into that circuit?

Thanks...Joe

[RBM]

The NEC requires GFCI protection for people, so any garage outlet that is designed for general use requires protection. A ceiling outlet is not considered accessible for general use, and yes a single receptacle indicates it is specifically for that GDO. The same goes for outlets with stationary appliances parked in front of them. There may be good reasons to protect a GDO with GFCI, however the NEC doesn't require it.

[RBM]