Does a New Detached Garage Require Two Circuits?

[jerlane]

We are building a two car 24x24 detached garage and I am GC'ing the build. An electrician is doing the work as a side job, so I pulled the permit.

The electrician that did the house work (just finished the house) ran a line from the circuit breaker to the outside of the house for the garage. He ran a single 20A 120v line. We're planning to run that to the garage underground through conduit.

I reached out to our inspector to try to avoid any mistakes and he said we need a circuit for the outlets and a separate circuit for the lights. Does this make sense? Both electricians I've talked to said one single 20A line should be fine.

The basement is already finished, so running a second line from the breaker will be a challenge.

Thanks in advance!

 

[75gmck25]

Maybe you didn't ask the inspector exactly the right question, or he misunderstood.

You do need switched lights inside, and outside next to the man door, and you do need a minimum number of GFCI receptacles (usually one per car bay). However, I believe they can all be on one circuit.

Bruce

 

[BillK]

I am just curious. Does the inspector understand that this is a DETACHED garage ?? I didn't think you had to have any electric to a detached garage.

 

[wyliesdiesels]

Can NOT run 2 separate circuits to a detached building- code does not allow it.

If it were mine, i wouldve ran a feeder thats a lot larger than 20a especially since its brand new.

EDIT: damn phone left out a word.

 

[Aceman]

A first time poster going cheap on the electrical with a supposed "electrician" that's side jobbing and he can't answer your simple questions???

Good luck.

You get what you pay for.

 

[bruincounselor]

I put 200 amps in my smallish garage, and 19 outlets in the single size shop bay. 20amps will probably do the minimum to meet most local code requirements, buy why not have a little extra for future use?

 

[wyliesdiesels]

A first time poster going cheap on the electrical with a supposed "electrician" that's side jobbing and he can't answer your simple questions???

Good luck.

You get what you pay for.

Agreed!

 

[larry4406]

I build production homes in Montgomery County MD and one of our models has a detached garage about 15' from the house.

The bear bones wiring approach is a single 14/2 15A dedicated circuit run to detached garage where it terminates in a single gang box centered on the end wall of one of the two car bays. This box is fitted with a GFCI outlet which then feeds the exterior (jelly jar) and interior (2 keyless) lighting circuits, another outlet centered on the other car bay end wall, the single overhead plug for the 16' garage door opener, and one exterior outlet. So tripping this single GFCI kills the entire detached garage.

Not my choice on this method, cost derived minimum for a production home. Have built about 15 of these and not one customer wanted any garage power upgrades.

 

[AntonLargiader]

This box is fitted with a GFCI outlet which then feeds the exterior (jelly jar) and interior (2 keyless) lighting circuits, another outlet centered on the other car bay end wall, the single overhead plug for the 16' garage door opener, and one exterior outlet.

I've read different interpretations of the new "The branch circuit supplying this receptacle(s) shall not supply outlets outside of the garage" section. Is "outside of the garage" being interpreted as "not on the inside" or as "other than the garage"?

From 210.52(G) or thereabout.

 

[larry4406]

I've read different interpretations of the new "The branch circuit supplying this receptacle(s) shall not supply outlets outside of the garage" section. Is "outside of the garage" being interpreted as "not on the inside" or as "other than the garage"?

From 210.52(G) or thereabout.

Well in my case I’m assuming garage structure only. They all pass inspection this way which doesn’t mean much.

 

[Leaflessshadetree]

Required by who?
If it's mine it requires at least a 240V 20A feed (more Amps even better). It doesn't add much cost to do 240V and have 2 circuits in the garage so you don't have to kill power to the whole building when you need to do work.

 

[AntonLargiader]

Well in my case I’m assuming garage structure only. They all pass inspection this way which doesn’t mean much.

Actually it looks like they cleaned that up for 2017. Garage receptacle outlets may power outdoor outlets, but nothing else and it must be 20A. 2014 had the "outside the garage" wording.

 

[pattenp]

First mistake was running only a 120V 20A feed to the garage. At an absolute minimum I would have installed a 240V 30A feeder. If the inspector is in fact requiring the outlets and lights to be on separate circuits then you will need to install at least a 2 space subpanel to branch out the circuits and put the outlets on a 20A breaker and lights on a 15A breaker. You need to be mindful that both the lights and outlets will only have 20A to draw on. You should use LED lights to keep the amp draw for the lights to a minimum.

 

[Bolson32]

I build production homes in Montgomery County MD and one of our models has a detached garage about 15' from the house.

The bear bones wiring approach is a single 14/2 15A dedicated circuit run to detached garage where it terminates in a single gang box centered on the end wall of one of the two car bays. This box is fitted with a GFCI outlet which then feeds the exterior (jelly jar) and interior (2 keyless) lighting circuits, another outlet centered on the other car bay end wall, the single overhead plug for the 16' garage door opener, and one exterior outlet. So tripping this single GFCI kills the entire detached garage.

Not my choice on this method, cost derived minimum for a production home. Have built about 15 of these and not one customer wanted any garage power upgrades.

This makes my skin crawl.

 

[AntonLargiader]

OP. it may depend where you are and what code cycle you are on. Why not tell us.

 

[Lelandwelds]

Not my choice on this method, cost derived minimum for a production home. Have built about 15 of these and not one customer wanted any garage power upgrades.

Not one customer is a GJ member.

 

[Shiftless]

Not one customer is a GJ member.

As the professional electricians have already said, only one circuit is required and 2 are prohibited.

I'm afraid that for many people a garage is merely a storage unit conveniently located on the same property as their house.
How many of us can look around in their neighborhood and see most of the garages stuffed with old furniture and piles of cardboard boxes full of ****?

 

[AntonLargiader]

A MWBC would have been a good idea compared to a single circuit. That is allowed by code. Two circuits for a few dollars more than the cost of one.

 

[ard]

I am reviewing a garage build for my ACC:

1056 sqft
3 car garage
foundation, stick built, stucco, Sheetrock, tile roof

8 ft walls
One circuit, 12 can lights, 8 receptacles,

Makes my skin crawl....

 

[jerlane]

OP. it may depend where you are and what code cycle you are on. Why not tell us.

Minnesota, so it looks like we are on 2017. The electrician that did all the house work which included the rough in for the line to the garage said that the code changed or went into effect in July.

I appreciate everyone's comments and wish we could have gone deeper with the garage plans, but this was at the end of our whole house remodel and the budget was maxed out already. I'm not planning on doing any major work out there and will have a dedicated shop area in the basement. So, hopefully the single 20amp line will be adequate. I did get LED lights as suggested by another member here.

As I was typing this message the inspector called me back and was very nice. He said that since the rough in at the house was done prior to the code change, he would sign off on it. So it looks like I am good to go.

Thanks again for the insight. I'll likely be back here to get more info on other projects once it's up and running. Floor finish maybe???

 

[wyliesdiesels]

A MWBC would have been a good idea compared to a single circuit. That is allowed by code. Two circuits for a few dollars more than the cost of one.

Code considers a MWBC one circuit not 2.

 

[ard]

Might I suggest you use a conduit that can handle a larger wire in the future????

Might cost you $40 more.


(That way of you or someone else ever needs more, at the least you arent re-digging.)

 

[bepjrfan]

I am reviewing a garage build for my ACC:

1056 sqft
3 car garage
foundation, stick built, stucco, Sheetrock, tile roof

8 ft walls
One circuit, 12 can lights, 8 receptacles,

Makes my skin crawl....

That is nuts... I was thinking 6 outlets on a 20 amp circuit was going to be a bit much, much less 12 lights and 8 receptacles... What kinda can lights are getting put in?? Can't imagine there will be too much left over power to power the outlets...

When you run a circuit like this, do you run it through a gfci before the can lights or run the outlets on the backside of the lighting and have the GFCI after the lights in the circuit?

 

[larry4406]

As the professional electricians have already said, only one circuit is required and 2 are prohibited.

I'm afraid that for many people a garage is merely a storage unit conveniently located on the same property as their house.
How many of us can look around in their neighborhood and see most of the garages stuffed with old furniture and piles of cardboard boxes full of ****?

Yes this is it.

We GJ members are a dying breed. Sad

 

[AntonLargiader]

Yes this is it.

We GJ members are a dying breed. Sad

Not sure what you're referring to but the OP's inspector was apparently right. Two circuits are required under 2017 code. The lights may not be on the receptacle circuit. A MWBC would have met the requirement; it's technically one circuit so it can feed the garage without needing a panel.

As for what a residential garage is used for, what's so wrong with having a garage that you only park cars in? If you want a shop, you can build one or convert your garage into one (or convert it into anything else) but it's basically for parking cars in. Minimal electricity is all that's needed for that.

 

[mm08822]

Not sure what you're referring to but the OP's inspector was apparently right. Two circuits are required under 2017 code. The lights may not be on the receptacle circuit. A MWBC would have met the requirement; it's technically one circuit so it can feed the garage without needing a panel.

As for what a residential garage is used for, what's so wrong with having a garage that you only park cars in? If you want a shop, you can build one or convert your garage into one (or convert it into anything else) but it's basically for parking cars in. Minimal electricity is all that's needed for that.

This is correct. NEC 2017 has a new requirement - 210.11(C)(4) that did not exist in the 2014 code.

Need at least one 120v 20a ckt for recept outlets in attached and detached garages with power. This circuit shall have no other outlets.

So that wording puts lighting on a separate ckt. Therefore, 2 minimum. A MWBC would be the minimum unless you go the sub-panel route.