Hello everybody and stupid electrical question

[David Alfon]

Hi everybody,

After more than a year reading almost every post on a daily basis, I finally decide to write my first post.

Like a lot of people I want to install a sub panel in my 2 car garage workshop (actually 3 but my wife agreed only on 2 ....).
I got most of the information I needed from the forum but I still have a stupid question.

My main panel (Flush monted) is in the garage and I want to put a surface monted sub panel just left to it. My question how do I connect my feeder from the main to the sub.

Hopefully I have been clear enough.

Thanks in advance for your help.

David

[Von Bickley]

David,

I'll try to get things started on this and I'm sure other people will jump in. If I was going to surface mount a sub-panel, I would plan on putting a piece of 3/4" plywood on the wall where the sub-panel will be going. Before I mounted the plywood, I would get my electrical cable from my main panel to the spot where I wanted the sub-panel. Your main panel is installed between 2 studs now. If you take off the cover, you should see some knock-outs on the side of the panel. You could take out a knock-out and drill a hole thru the stud to fish your electrical cable thru.

You will need a 4 wire cable for your sub-panel. You will have 2 hots, a neutral and an equipment ground. The size of the cable will be determined by what you will need. You will have a double breaker in your main panel that will feed the sub-panel.

You can make your piece of 3/4" plywood be big enough to surface mount your sub-panel, cover up your hole from getting the cable out, and big enough to surface mount a 2-gang box for receptacles at the panel.

Hope this helps and I'm sure you will get a lot of people jumping in on this.

Welcome to the Creek......

[randy street]

David,

Here is a link that has some images, you should be able to get the basic idea.

Link

Regards,

Randy

[David Alfon]

Von, Randy,

Thank you for your help.

But what I forgot to mention is that my garage is finish and I was wondering if I needed to use conduit from the main to the sub. I wanted at first to bring the feeder at the back of the surface mounted sub but it seems that the feeder need to arrive at the top. I am not quite sure that having a wire coming from a hole in the wall and entering the top of the sub is very compliant with NEC recommendations ....

Let me know your thoughts ....

[Von Bickley]

David,

You would use a cable that is enclosed and sometimes called entrance cable. You would not be running individual wires and would not need conduit for that.

[randy street]

Daivd,

Just be sure and check your local code. Where I live everything has to be in conduit.

Randy

[David Alfon]

It seems that I did not get a clear answer yet.

I try to rephrase my problem. I have a finish garage and my main panel is flush mount in the garage. I want to install a surface mount sub panel just next to the main.

So my problem is what the correct route to bring the feeder from the inside of the wall (main panel) to the outside of the wall (sub Panel).

Hopefully I am more clear now ....

(Von, Randy thanks again )

[Dave Bender]

A hole or notch in the stud. My main and subpanel are not flush mounted (raise about 3/4" above drywall) with the drywall but are installed between the studs. The electrician that installed my sub panel made the sub panel sit at the same height as the main and ran a 6" piece of conduit between the two boxes. The result was a small notch in the stud.

[Tom Godley]

Not sure how big your panel is or how many wires you now have to deal with.

I can assume that your current panel does not have enough spaces to do what you want to do. Otherwise you would just add to the existing panel

That probability indicates that you have a few wires to contend with inside the panel and may have limited holes left.

I mention this because as previous stated you often have a stud on either side of the panel and most of the wires come out of the top.

To add a wire to the side requires drilling out the stud area - I would not attempt this with power to the main panel !!

It is much safer to just plan on removing a section of the drywall around the panel -- remove enough so you can properly fish an adequately sized wire to the new sub panel.

You may have to back the new panel with plywood in order to attach it to the drywall. My code did not require this - but it had to be screwed to a stud -- no anchors!

It is a very quick job with the drywall removed -- The drywall is easy to fix.

I have learned that it is easier to remove a larger section of the drywall than you think you may need - you end up needing it Also, when you patch the area it is not as noticeable. I cut the drywall between the studs and just put the same piece back in using 1x2 screwed to each side behind the cut.

[David Alfon]

Tom, Dave thank you for your advice.

So if I do what you say my feeder will enter at the back of my sub (and not at the top).

[Tom Godley]

Yes -- you will use the large rear hole


Remember 4 wires to a subpanel

[David Alfon]

Ok Thank you Tom

[Ken Tucker]

It seems that I did not get a clear answer yet.

I try to rephrase my problem. I have a finish garage and my main panel is flush mount in the garage. I want to install a surface mount sub panel just next to the main.

So my problem is what the correct route to bring the feeder from the inside of the wall (main panel) to the outside of the wall (sub Panel).

Hopefully I am more clear now ....

(Von, Randy thanks again )

do you have attic space above run a fish tape run up and over