How to Wire a Garage Panel
Installing a Garage Electrical Panel
A few years back I installed a sub panel in my garage to run my 220 Volt for a welder and air compressor. I fed the sub panel with three # 6 AWG stranded wires. Two hots and a neutral. The sub panel has one 50 amp breaker for my 220volt welder, one 30 amp 220volt breaker for my air compressor, and one 20 amp 110volt breaker for an outlet. The three #6 AWG. stranded wires as I mentioned that feed this sub panel are are in 3/4 in. EMT conduit from the main in the house to the sub panel.
Sub Panel Ground and Neutral
The sub panel only has a neutral bus and no ground bus. I recently learned the codes have got stricter where as the 3/4 EMT is not good enough for a ground only. I am going to install a ground bus bonded inside the sub panel in the garage and going to use one #6 AWG stranded to pull two wires through the existing #/4 EMT that feeds the sub panel.
My question is on the two wires I pull through
One of course will be another #6 stranded and what should the second be for a ground? What type and what minimum gauge should a ground wire to a sub panel be with two #6 AWG stranded feeding the panel (hots) and a #6 AWG stranded feeding the neutral in the sub panel. I am fully aware that in a sub panel the neutral bus is separate from a bonded ground bus. I just need to know what is the smallest type of ground wire that should be running to the bonded ground bus in my sub panel and should it be solid or stranded. Thank You.
My reply to Bob:
Hi Bob - Great Electrical Repair Question!
A #8 Copper Ground would be fine - I would use Stranded Wire as it will pull easier, Identify the ground wire with green tape or purchase a Green?Colored Insulation. I don't know how far your EMT run is, but you may consider using wire lube to make it easier.At the Sub-Panel - if the Neutral?Bar is Bonded to the Panel?Enclosure?then remove the Green Bond Screw after you install the new Ground Bar.Make sure to turn off the Sub Feed Breaker!
Be Careful - Be Safe - Let me know if this helps.
I must say thank you for the timely response. You completely answered what I was looking for. I was kind of hoping that I could go one size smaller on the ground than the original 6 AWG. and you made my wishes comes true!
Wire for a Sub Panel
I will get a #8 stranded with green insulation as you recommend. This and the #6 AWG. stranded I run will be easier than two #6 AWG. stranded I was hoping to avoid. I will also get a bottle of the special lubricant and hopefully the old use one to pull two through will go smooth!
. I double checked and the neutral bus in the sub-panel is not bonded and totally suspended with plastic footing. I will sand the gray paint off the spot I am going install the ground busing a open spot of the sub panel to insure a good bond and install all my grounds so a fault will find it's way back to my main house panel ground if ever and I will be up to code.? Thank you for the excellent professional advice.
I just read your email and I never thought of that. That is an excellent idea!
It is about 50 feet of 3/4 EMT running from my main to the sub. I checked my local home depot and Lowe's and both are 89 cents a foot for #6 AWG. stranded so you do the math. (Yea, I know!
I actually was not looking forward paying such money for close to 60 feet of wire. There is a considerable price decrease for smaller wire. I think #10 is 20 some cents. I see what you are talking about. So I should use a existing #6 to pull the new #8 ground and a #10. Then once through I use the #10 to pull back the #6. You mentioned nylon rope. Is that like the ones you see in the rope isle in a hardware store I think usually white or something? I agree and I am definitely going to have a buddy help me pull. I will have him pull while I do the hard and messy lube end feed.
Installing a Sub Panel
I remember the first time I put the sub panel in a few years ago. I had the same friend help me. I have two identical cordless home phones that have the intercom option. I gave him one in the garage and I had the other in the basement. So whenever I told him to pull or stop we could perfectly hear each other hands free while working since we were in different areas and we could not hear each other. So you are so right when you say snaking it by yourself is tough. Again, great idea with the wire Dave!
I know professionals such as yourself know these little tricks that end up being huge. You just saved me a lot of money!
I appreciate your knowledge and advice and like to learn all that I can about wiring and electricity. And the thing is I really enjoy doing it and like to make everything perfect and neat. Although, my electrical belt is hurting my back from all the junk I don't need. I want to get a carry one like you professionals use!
Hi Bob, and Thank You for that nice reply!
Its so good to hear back from people - it makes what I do more meaningful. Say, I don't know how long the 3/4 run is back to the panel, and I don't know if you've already thought of this - but to save money you may consider attaching either a small nylon rope or a #10 insulated stranded wire to the #6 you are?planning on taking out - this way you'll be able to reuse the #6 and re-pull it back in with the #8 ground wire.
Pulling Wire in a Conduit
Another tip to help the pull, if you pull in a nylon rope or the #10 - lube it up with the pulling soap to pre lube the conduit for the two wires going right back in.Also - if you will be using a nylon line as mentioned above, just be careful that it is not too small because the friction can actually cut into and damage the existing wires. From time to time, if i'm doing something like this and I experience problems - I'll just pull back the whole set, add the other wire onto it and pull?them back in. See if you can get some help to feed the wire back in. Trying to do it yourself can be tough, but if someone is guiding the wires in and squirting a little lube along the way it goes so much better and you stand less of a chance of damaging the wire, or shaving it on the connector where it feeds into. A 3/4 inch plastic bushing will help prevent this as well, but they taper down the opening just a little.
Be Safe - be Careful!
I am going to get started on the garage again. I am putting up new lighting. I had some cheap 4ft shop lights (4 in a row going in a straight line)when during one of the coldest nights last February, they got ruined from the cold. And I mean they just quit working! not the typical flicker because they were not cold start ballasts. In fact, a friend told me he had the same thing happen to him. They were brand new in November when I put them up. I even hard wired 1/2 EMT to duplex boxes in my rafters switched by my main door. I should of known better by not buying the good one's for cold climates. I just bought two 8ft T12 H/O cold ballast to go across my main front of the garage then I also bought some of those T8 eight footers with the quad 4 ft bulbs to go down the middle of my garage and over my tool area since I work on cars.? I also know about the phase out but I just the T12 H/O put out more light so I wanted at least a couple. I am wiring them all in on two different switches.
My garage is unfinished so I can get everything the way I want real easy so when I eventually insulate and finish. I will have everything the way I want it. I also have a ceiling suspended 45,000 btu gas heater I had installed 4 years ago, ran the gas line and all but I paid a local company to install the heater and chimney in the roof. But boy does it cost me in the winter to run that heat since I am not insulated yet, LOL! If you can't tell by now I am in a cold climate in winter time. I am just outside of Chicago. Just me and my wife. I am sorry to learn of your Father's passing. I can relate because I lost my Mother just three years ago whom I was really close with and took care of until her passing. But a Father is where we get our knowledge of crafts and advice. I wish you and your family well during this difficult time and I'll keep you in my prayers and stay strong knowing your Father made you who you are and did a fine job by someone who goes out of their way helping strangers over the internet with their problems to pass on the gift of knowledge and craftsmanship he taught you. Hey, have you purchased from that link you gave for wholesale? Just wondered what you thought of them.? Well, going to get started.
Thanks again for all your help. It's nice to know there are still some great people left out there.
Wholesale Electrical Suppliers
This will give you an idea of possible wholesale suppliers to check out. That price is a little high - I pay 68 cents. Make sure those guys are not trying to sell you the Fine Strand wire but get regular THHN wire or THWN wire or even THW, but not the rubber insulated type. As for pulling wire - wow I've got all kinds of stories, especially hearing my Dad yell at be to Feed That Damn Wire! (long ago). I really need to put a page together dedicated to my Dad - I just lost him and he's the guy that sparked my interest.As for the tools - I'll be putting up a page soon that will show exactly what I use. Yes, you gain a lot of weight, but you learn to only carry the tools you need. I use one set for rough wiring and another for setting trim - then others for conduit work etc. I have a bad back as it is, so I need to be careful and not over do it.
Another helpful item is a deep tote-tray, especially for attic and crawl space work where you don't wear a belt, otherwise you loose your tools.
All the Best!