??Changing out the electrical panel in my detached garage

[sstock]

Hello, this is my first post, but have lurked for some time now, so hello. My garage/shop is 175' from my house, it was built around 1980 or so. It has a small panel in the detached garage fed off the 200 amp panel in the house. Wire connecting the two has three conductor of 2 gauge. 50 amp breaker in the main panel and no main disconnect in the detached garage. I am making my garage bigger and want to upgrade to include a small plasma cutter and mig, separate 20 amp 110V outlet circuits and light circuits two. I will run a 5kw electrical space heater too. The existing panel has no ground rod outside the garage and the neutrals and grounding wires terminate on the same bar.
Questions are can I upgrade to a newer panel without running a separate grounding wire back to the main panel? This would be mostly impossible to do. If I can upgrade to a new modern sub panel, do I drive a separate ground rod at the garage and bond the panel to the ground rod and unbond the neutral and grounding wires from each circuit? I have read many threads on the search and it seems everything changed in 2008, and I'm confused as to what will be right and what will work safely.


Thanks in advance.

 

[pattenp]

Since there is no equipment ground back to the house leave the grounds and neutrals bonded in the new garage panel and add the ground rods at the garage. Connect the ground rod conductor to the same bar as the neutrals and circuit grounds are connected to in the new panel. Do you have any other wires or metal pipes running between the house and garage?

 

[sstock]

Understood, thank for clarifying this to me. No other metallic connections back to the home structure from the garage, just a pvc water line.
Thank you.

 

[wyliesdiesels]

What type of condit is used to feed the garage? PVC or metal?

 

[pattenp]

Duh.. I didn't think to ask that question.

What type of condit is used to feed the garage? PVC or metal?

 

[VHF]

If your #2 wire is aluminum you can put it on a 90A breaker in the house; if copper then a 100A breaker. In either case, you can buy a 100A panel for the garage with a 100A main breaker. The 90/100A breaker in the house provides the overcurrent protection for the wiring to the garage; the 100A main breaker in the garage just serves as the disconnect.

 

[sstock]

Thanks VHF. No conduit used on the garage, it is 2-2-2 direct bury secondary cable.

 

[sstock]

Panel installed, ground rod is in and a number 8 copper ran from neutral/ground bar to ground rod. Last question, do I use the little green screw to bond the neutral/ground bar to the panel or leave this out??
Thanks in advance.
Steve

 

[pattenp]

In your setup since you don't have an equipment ground wire back to the house you leave the neutral/ground bonded and bonded to the case. Leave the green screw in.

Edit: Also... Grounding electrode conductors smaller than #6 shall be protected in conduit. And did you put in two ground rods at least 6 feet apart from each other?

Panel installed, ground rod is in and a number 8 copper ran from neutral/ground bar to ground rod. Last question, do I use the little green screw to bond the neutral/ground bar to the panel or leave this out??
Thanks in advance.
Steve

 

[sstock]

Thanks for the info, I did run the #8 in conduit, but only used one ground rod, sounds like I need another. I take it they need to be 6' apart with a copper #8 between them. Back to the depot. The electrical guy and I am on first name basis, lol.

 

[Charles (in GA)]

By code, the ground wire to the rods must be continuous, un-interrupted, and cannot be spliced or have connections of any kind, with the exception of certain approved permanent connections such as exothermic welding.

You will need to buy a complete new piece of wire to make the ground run with. If you buy #6 solid copper, you can run it without the protection of the conduit, which makes it much easier.

Charles

 

[sstock]

Roger that. Boy this electrical code is stringent stuff.

 

[Aceman]

By code, the ground wire to the rods must be continuous, un-interrupted, and cannot be spliced or have connections of any kind, with the exception of certain approved permanent connections such as exothermic welding.

You will need to buy a complete new piece of wire to make the ground run with. If you buy #6 solid copper, you can run it without the protection of the conduit, which makes it much easier.

Charles

It only has to be continuous from the first rod to the panel. You can use another jumper wire and a couple more acorn clamps to attach the second rod to the first.

On new installs we always use one continuous piece, it saves you one acorn clamp. But when we do upgrades on existing services with only one rod, I'll drive a second rod and simply connect the the two together.