Garage Subpanel Project - Problem With Main Panel - Advice Please

12 years ago

Oof, my garage subpanel project has run into a problem. It turns out - I foolishly failed to check this, but now I know - that the lower breaker positions on the cover of my 100A main panel are fakes. There is no busbar there. So as things stand my main panel is completely full, there is no room to add a 240v circuit to drive a garage subpanel.

I know one solution is to replace the main panel with a larger one. Here is the problem - see the panel location, pictured below. I am not convinced it is legal under current code. There is 30'' of wall, but that includes the main stack, the utility sink, and some other plumbing. I am happy to lose the utility sink, which we never use, if that will make the location acceptable for a new panel.

The adjacent wall is a compliant location, once I move the freezer. But most of the cables and wires will not reach, they will have to be extended, that's a lot of junction boxes. The main service won't reach either.

Either way, I think a new main panel is beyond the scope of my DIY ambitions, this project would cost (guessing) $5K. By the way, all our large loads are gas (dryer, oven, heat) so we don't actually ''need'' a higher-amp main panel, but naturally if I did spend the money for a new main panel, we'd go for a 200A since that seems to be expected nowadays.

Or, I could add a subpanel on that adjacent wall, shift over a few circuits whose cables do reach, and then proceed with the garage subpanel powered from the main panel as planned before. That, I'm ok with DIY'ing, with permit/inspection of course.

Can you guys give me some advice? What would you suggest? It seems more elegant to simply put in a larger main panel, but I was planning on spending $1K not $5K.

Here is a link that might be useful: My prior garage subpanel thread

Sort by:Oldest

Comments (5)

John Liu
Original Author
12 years ago
Another view - the freezer location is, I think, a completely compliant panel location, for main or subpanel. But only a few of the existing cables will actually reach, without extending.
Ron Natalie
12 years ago
You can always use your existing panel as a large junction box.
Related Professionals
Burlingame Electricians · Albany General Contractors · Artesia General Contractors · Auburn General Contractors · Gainesville General Contractors · Henderson General Contractors · Klamath Falls General Contractors · Los Alamitos General Contractors · Makakilo General Contractors · Whitney Solar Energy Systems · Danville Home Automation & Home Media · Fort Lauderdale Home Automation & Home Media · Medford Home Automation & Home Media · Plantation Home Automation & Home Media · Poway Home Automation & Home Media
John Liu
Original Author
12 years ago
I took another look.

There are 16 positions in the main panel.
- 4 positions are filled with 240V breakers (50A A/C and 30A dryer).
- 3 positions are filled with full-size breakers serving 3 circuits, each 15A
- 9 positions are filled with piggy-back breakers serving 18 circuits, each 15A . . . but one of them is the existing garage circuit which I won't need.

So, seems I might have some more alternatives.

#3
- Replace the 3 full-size breakers with piggy-back breakers, and eliminate the existing garage circuit, that frees up 2 positions, which if adjacent gives me room for my 60A 240V garage subpanel breaker,

#4
- Remove the 30A 240V dryer breaker, and replace with my 60A 240V garage subpanel breaker.
- Gives up the option of using an electric clothes dryer - I don't care (we have a gas dryer) unless there is some requirement that a house have a clothes dryer circuit.
- We had planned to drive my wife's someday pottery kiln from the dryer circuit, but maybe the kiln can be installed in the garage workshop instead, not sure what she'll think about that but I would personally feel a little better (safety, venting).

Also the options outlined in the initial post - #1 new main panel at the adjacent location, or add #2 subpanel in the basement plus the garage subpanel.

I'm having trouble figuring out which solution seems better . . . balancing the desire to keep the cost down and the desire to not do something that is basically kludgy despite passing inspection.
John Liu
Original Author
12 years ago
I went looking for info on the panel. It says it is a Square D QO 20 MW 225. I can't find the specs for this. It has 21 circuits of 120V and 2 circuits of 240V, right now. In plan #3, it will have 20 circuits of 120V and 3 circuits of 240V. In plan #4 (drive garage subpanel from position of un-used dryer breaker, it will have 20 circuits of 120V and 2 circuits of 240V. In plan #2 (basement subpanel) it can have fewer 120V circuits but 3 circuits of 240V. I'm not sure if any of the above are ''problems''.
joed
12 years ago
Option 4. There is no requirement to have a 240 dryer receptacle.