Adding an extra disconnect

Hi all,

I have learned a lot from this board, thank you all very much for sharing your knowledge.

I am upgrading my garage by adding a subpanel. I am running 6/3 Romex (the wire will never go in ground or outside the structure so Romex should be fine) from the main panel on a 50 AMP 2-pole breaker. I believe 6/3 Romex is rated up to 55 Amps, and while I think you can round-up to the next available breaker (60 amp), I don’t think I will need it. I am only planning to run lights, a 240-volt air compressor, a bunch of 120-volt tools. That’s about it. No major appliances that would ever go over 40-amp even. I am using a 125-amp rated panel with NO main-breaker in the panel.

I would like to add a disconnect to the garage itself so I can shut the power off to the garage easily without having to walk over to the main house panel and shut off the 50-amp breaker. I was planning on buying this:

Here is my question:

The switch has 3 poles. One for each hot, and one for the neutral. Since I am running Romex with 3 wires plus the bare ground, what do I do with the ground (bare copper)? Do I add a grounding bus bar into the switch panel? If so, do I bond the grounding bus bar to the panel? Then when I continue from the disconnect switch to the sub-panel itself do I just run the ground off that grounding bus bar to the sub-panel?

Thank you all in advance for the help and suggestions.

This board is more for home inspection type questions, not a DIY how-to board.

It would be easier to use a panel with a main breaker built in.

I agree with Jim this isn’t the place for DIY advice and also, go with the MAIN CB in the panel. Other than that you might consider getting some help from an electrical professional.

I understand, I was more asking what is up to code rather than how-to. I should have explained that. I can get the electricity to work, I’m not worried about that, I just want to be sure to pass inspection when it comes.

What Jim and Robert stated above. Trust them. They know their stuff.

Also, most Home Inspectors are not Code inspectors. Although we are knowledgeable about code, and use it as a reference, we typically don’t care what code is. We want it right, and safe.

Now, if I was inspecting a (older) home/garage, and I noticed there was a new panel/subpanel installed, some of my first thoughts would be… “was a permit obtained for the work, and did the AHJ perform their inspections”? These questions are clues (early warning signs) as to what I may or may not find during my inspection. If I am unable to determine, I always recommend my client request copies of permits from the seller.

So, did you pull a permit for your upgrade? Most all municipalitys require them for panel/subpanel work.

Does your municipality allow the homeowner to perform panel/subpanel upgrades? I am finding that more often lately, they do not. A licensed electrician is required.

Good luck.