How To Install A Sub Panel Next To Existing Main Panel

Demands on our home electrical system is steadily increasing. This means we are filling all of the space in our main electrical panel and that will limit the electrical appliances you can install, getting EV charging at home, or make installing solar panels a more expensive proposition. I will show you what is involved when installing a Square D QO 125 AMP Sub Panel right next to my existing main electrical panel.

Chapters
0:00 Project Setup
1:12 Positioning The Subpanel
4:17 Connecting Conduit Between Main Panel and Subpanel
7:21 Mounting The Subpanel
8:44 Why I am Installing This Subpanel = Solar Panels
9:58 Moving Circuit Breakers and Running Wire
14:30 Validating The Wiring

DISCLAIMER: This video and description contain affiliate links, which means that if you click on one of the product links, I’ll receive a small commission.

[mnrobards]

Great Video. Two things I would do different. Torque all of the terminations. and add some white tape on the neutral.

[johnvillalovos]

I would recommend using a torque wrench/driver. Current code requires it and frankly it is a good idea. I think a lot of people would be surprised on how hard it is to tighten things to the correct torque.

[sadbuttrue]

I always used cardboard that went across the lugs for extra protection. Many times had to wire hot due to customer needs. Really easy to cut a scrap piece to fit between the flanges. It's way too easy to forget about those HOT lugs.

[flunky]

I believe it’s code to identify circuits when relocating them such as in this instance. Meaning being able to identify which neutral goes with which hot, both in the main panel and in the sub panel. This is done so that in the future if you ever need one of those circuits on either a GFCI or AFCI breaker, then you be able to do that. Don’t know the exact code article but I was looking into it a few months ago when relocating a main panel and we would put zip ties around the hot/neutral together to identify them as belonging on the same circuit.

[rhtservicesllc]

One suggestion would be to use red electrical tape and white electrical tape on the ends of the wire between the panels.
This will make it easier to diagnose if there a problem with one of the hit phases and make it obvious about which wire is the neutral, since all the wires between panels are black.

[joekagerer]

Thanks for this video I had a sub panel professionally installed when I bought my 60 yo house 10 years ago. I do a lot of my own single circuit stuff but this was a good primer for a panel. Not rocket science but a lot of things you need to be aware of. I will probably never do this job myself, but it was good information for me.

[ncooty]

The main lugs are a dissimilar metal from copper. Therefore, it's a good idea to use an oxidation inhibitor (and remember to wiggle and retighten those stranded conductors).

[kommoncents]

You did a great job bringing the wires to the sub-panel. I did a similar install only I put a 14" metal access panel under the sub panel to give easier access to make future connections.

[LordSaliss]

That spacing you ended up with after cutting everything was absolutely beautiful.
I know it is drastically cheaper using the parts that you did, and that is a big reason even on its own, but why not take this opportunity when needing the subpanel for solar to use a smart panel like Leviton or Span? Being able to get really accurate readings on every circuit in that subpanel is pretty useful for seeing power draw when on battery (if you have one) or from your solar directly. I like the Leviton panel personally since it both looks nice, has indicators positioned so you can see status with the panel door closed, and you can choose specific circuits to be smart and go with cheaper breakers that are not smart for other circuits you don't care about, or the potential to upgrade to a smart breaker whenever you want.

[davidgodfrey]

Starting work on my sub panel today and this is the very video I'm using as guide. Thx for helping us all out.

[erikcable]

Good show here, for you DIY'ers go ahead and pull a permit, costs under 200 bucks. Let the inspector sign off on your installation. keep a record for insurance coverage.

[jimpie]

I did something similar n my old house, I added a 50amp breaker in a new panel, connected it with a metal conduit. Both panels were the same size so I covered everything and it had 2 doors that opened out exposing both. The doors came off the wall about 1 1/2” and across the top was a 2x4 that was about 2” higher than the panels, but far enough away, that you could connect metal conduit (code in my area) without damaging or cutting anything. I also had a dropped ceiling so anything could be easily added anywhere.
In my current home I added a 50amp sub panel in the garage, before I finished the basement. The panel was added for a welder and more power in the garage. This panel was sent in like yours and a plywood cover and small door for the welder plug-in. Thanks, your video’s are always wonderful and helpful. God bless you!

[MB-irxf]

In my area (Midwest) pvc conduit is illegal, splices inside the panel are not allowed.

[robertgrlic]

Great video! Not certain in Canada, I believe the CEC ( Canadian Electrical Code) doesn't allow splicing inside of main panel if exiting to a different system. If any Canadian electrician can comment.

[TheJXB]

You make it look easy, which, I think, is the point. You instill confidence. Thank you!

[vg]

You are really going at it these days. I wish I had your energy and your back and neck. 🤣 Looks like you covered all the bases. I'd be willing to do that kind of work, but it would take me a lot longer because I'd have to take breaks. That is, I have the electrical and electronics experience, but I'm not a professional electrician, and I'd also have to study all the codes to be sure it would all meet spec. Looking forward to the next one. Thanks, Scott.

[DavidLucBelanger]

I would suggest to get black, red, white and green wire next time. It's the same price per foot and you can quickly identify which wire is what.

[hassanbazzi]

Knowledge is power. I know I will not attempt to diy but I have some knowledge and reference to hire a contractor. Thank you for sharing

[ncooty]

Thanks for the video. Surprised not to see a whole-panel surge protector.

[johnhooton]

I noticed your main panel had a few ground and neutral wires in the same hole . This is a no-no, neutrals have to be one per hole. Depending on panel some do allow more than one ground per hole.