Partially Detached Garage Subpanel

[AndrewDouglasBird]

The wiring in my garage is from the 50's, has no ground wires and needs to be re-wired. It's a detached garage, spaced about 6 feet from the house, but is connected to the house by a small roof section over the doors going in the house and garage. The attic in the house is connected to roof connecting the two, so running wire into the garage will be easy.

But this has me wondering, do I treat this like a detached garage, or an attached garage in regards to grounding?

 

[wyliesdiesels]

You need a ground wire either way via 4-wire feeder.

The only question is whether you need electrodes.

Adding them wont hurt other than a little to your wallet

 

[AndrewDouglasBird]

That makes sense. I was wondering if the ground and neutral needed to be bonded, but ALL sub panels have to have them un-bonded, correct?

As far as ground rods go, do I need 1 or two? I seem to be finding information that says both.

Thanks!

 

[Norcal]

If it has a breezeway then I would call it attached.

 

[wyliesdiesels]

All subpanels on new construction should not be bonded.

You need 2 rods spaced min 6' apart

 

[aandpdan]

Check with your local AHJ as to whether or not it is considered attached or detached.

If you do need ground rods you'll need 2 - unless you can find someone to test the one for 25 ohms or less resistance to ground NEC 250.56. It's easier just to drive the other one.

3 wire subpanels, older code versions, are bonded. 4 wire, new code, are not bonded. You'll be using 4 wires.

 

[AndrewDouglasBird]

Thanks everyone!

Now I just need to decide if I want to go with 8ga or 6ga wire...

 

[alfredeneuman]

If it has a breezeway then I would call it attached.

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THIS
and if it's attached no ground rods are needed; just a 4 wire feeder.

 

[b-boy]

Check with your local AHJ as to whether or not it is considered attached or detached.

If you do need ground rods you'll need 2 - unless you can find someone to test the one for 25 ohms or less resistance to ground NEC 250.56. It's easier just to drive the other one.

3 wire subpanels, older code versions, are bonded. 4 wire, new code, are not bonded. You'll be using 4 wires.

Follow up question - I understand the grounding rods need to be 6 ft apart, but how far from the structure should they be?