Wiring New Metal Garage

[ACLazer]

New Member, thanks for the addition.

I'm having my new garage put up next week.
It's an all metal 20x25, 10' high, with two 8x8 manual garage doors, two windows and one man door.

Do I have to do anything special when wiring this building? I'm using 12-2 CU MC Metal Clad Armorlite Cable inside. I already added a 20amp Breaker in the main fuse box on the house, and buried 60' of 12-2 cable underground in PCV Conduit, with the conduit coming out of the front right corner of the concrete pad.

Do I need any kind of special grounding rod in the ground, or anything like that?

Thank you in advance.

​

 

[rancherbill]

Welcome.

Someone will wander along and know the answer. They need to know where you are - US Canada etc, and probably the state. You should add it to you profile for this and future questions.

 

[ACLazer]

Thanks, I'm in North Carolina

 

[Norcal]

New Member, thanks for the addition.

I'm having my new garage put up next week.
It's an all metal 20x25, 10' high, with two 8x8 manual garage doors, two windows and one man door.

Do I have to do anything special when wiring this building? I'm using 12-2 CU MC Metal Clad Armorlite Cable inside. I already added a 20amp Breaker in the main fuse box on the house, and buried 60' of 12-2 cable underground in PCV Conduit, with the conduit coming out of the front right corner of the concrete pad.

Do I need any kind of special grounding rod in the ground, or anything like that?

Thank you in advance.

​

MC cable is subject to similar rules as NM sheathed cable "Romex®" needing to be protected from physical damage.

 

[ACLazer]

Yes, thank you Norcal, I appreciate the response.
Just wondered if I need any kind of special grounding for the building, or just treat it like a normal wood stud garage?

 

[Pompey]

I just had a meter base and 200 amp panel fitted to my new metal building and the electrician added a 200 amp aluminum bonding ground cable from the load center ground to the metal building frame.

If you have a sub panel in the garage then you need to separate the ground and neutrals in that sub panel. If you don't have a subpanel and the grounds and neutral are coming from the house then it would not hurt to add two 8 foot ground rods, 6 feet apart at the new building.

I would definitely make sure that the electrical ground is bonded to the building frame. I think that building ground bond needs to be at least 6 awg copper wire but I would check the codes to see.

 

[TurnipTruck]

Uh, what kind of wire did you bury in conduit?

 

[ACLazer]

Thank you Pompey, thats what I was looking for.
I just have dedicated 20amp service coming in from the Main Box on the house.
I will look into code's for the ground, and thanks again.

The garage will mostly be used for vehicle storage.
All my Tools, Compressor, Jacks etc. will still be in the 24x24 attached garage to the house.

Turnip Truck, I just have a dedicated 20amp service coming in from the main box on the house.
I have about 60' of 12-2 Romax inside a sealed watertight PCV Conduit buried 18" in the ground.

 

[dscheidt]

Thank you Pompey, thats what I was looking for.
I just have dedicated 20amp service coming in from the Main Box on the house.
I will look into code's for the ground, and thanks again.

The garage will mostly be used for vehicle storage.
All my Tools, Compressor, Jacks etc. will still be in the 24x24 attached garage to the house.

Turnip Truck, I just have a dedicated 20amp service coming in from the main box on the house.
I have about 60' of 12-2 Romax inside a sealed watertight PCV Conduit buried 18" in the ground.

Romex is not approved for use in wet locations -- and underground conduit is a wet location. There's a reason for that: it's not waterproof. IT will fail. Replace it now.

Were it mine, I'd pull at least 4 12 ga wires, and run a MWBC, which gives you two 120V 20A circuits in the shop. I'd almost certainly actually pull bigger wire, and install a subpanel. That will make it possible to do things like add HVAC or a car charger later on.

 

[ACLazer]

Dscheidt, thank for the response but it's too late to change all that now. I'm not going to be using it as a shop at all. It will be used to store vehicles "only". No HVAC, no garage openers, and nothing other than a couple of LED shop lights and a Battery Tender Junior.

Thanks again and appreciate your response

 

[sparky 1971]

Yes, thank you Norcal, I appreciate the response.
Just wondered if I need any kind of special grounding for the building, or just treat it like a normal wood stud garage?

Deleted due to the fact I missed the underground Romex and the "it's too late to change that now" response.

 

[wyliesdiesels]

Thank you Pompey, thats what I was looking for.
I just have dedicated 20amp service coming in from the Main Box on the house.
I will look into code's for the ground, and thanks again.

unless all youre doing in there is running a few lights and charging some batteries, 20a aint gonna cut it.

Turnip Truck, I just have a dedicated 20amp service coming in from the main box on the house.
I have about 60' of 12-2 Romex inside a sealed watertight PVC Conduit buried 18" in the ground.

NM-b is NOT permitted underground or outdoors. and PVC is NEVER water tight.

This needs to be ripped out and changed to THWN wire.

 

[wyliesdiesels]

Dscheidt, thank for the response but it's too late to change all that now. I'm not going to be using it as a shop at all. It will be used to store vehicles "only". No HVAC, no garage openers, and nothing other than a couple of LED shop lights and a Battery Tender Junior.

Thanks again and appreciate your response

its wrong and it will fail. easier to change it now. why come on here asking for advice if you wont follow basic advice given?

 

[ACLazer]

Ok, thanks, I will try and pull through underground cable through the PCV.

 

[Metal-Marc]

I just have dedicated 20amp service coming in from the Main Box on the house.

Even if you don't need it now, I'd go at least for a 240V 60A service in the garage.

 

[ACLazer]

Thank you, something to think about for sure.

 

[jsundin65]

Thank you, something to think about for sure.

I am new here but I think people are giving advice based on things they learned (or didn't do the first time). I am also building a garage and am making mistakes along the way. In my old house, I had 30amps from the house, feeding into some lights and outlets. I plugged a portable AC in and then would run either sander or scroll saw and a vacuum. I was always tripping breakers in that. My new building will have 100A service. I am not a huge workshop but am probably the power child for "you never know what hobby you might start later".
So, if you can get more power, I think you will appreciate it later.

 

[Darryl_N]

Even if you don't need it now, I'd go at least for a 240V 60A service in the garage.

2020 NEC says the smallest allowable panel+breaker+feeder for a detached non-dwelling building is 60 amps. However, it is legal to run a 20A branch from your main panel but the first receptacle nearest the entry point must be GFCI. UF-B is like romex but can be direct buried. Neutral and ground must not be connected together and must run all the way back to the main panel. Feeder ground must be attached to a ground rod, ufer, or grounded water pipe at the detached building, as well as the ground terminal on each receptacle and box.

Source: me reading the code online (requires much coffee) and doing my own permitted electrical work. I'm not an electrician. I might be wrong, you might get killed, and it will hurt the whole time you are dying.

You can read the 2020 NEC code for free here:

NFPA LiNK®

The leading information and knowledge resource on fire, electrical and related hazards.

link.nfpa.org

(Create a free account and log in, then paste the above link. The free access button is kinda buried.)