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Subpanel Questions/Running electrical to garage.

42K views 28 replies 10 participants last post by  gregzoll 
#1 ·
My wife and I moved into a house almost a year ago, and I am finally getting around to some of the projects I had in mind. One of these projects was to upgrade the electrical in my detached garage. Currently it is only one circuit off the main breaker panel, and the only electrical in the garage is one receptacle, one incandescent fixture, and the garage door opener...woefully inadequate for my needs.

I have been reading up on wiring, and I have a pretty good understanding of exactly what I need to do. I plan on doing most of the work myself, and then having an electrician come in to review it, and make the final connections once he (or she) is satisfied with my work.

I plan on running a subpanel to the garage,a nd I would like to put a 100 Amp panel out there. I've been looking just at home depot/lowes so far, and I don't see any subpanels that really are what I am looking for...some are as much as 125Amp, but most have only four breakers or so. I plan putting more circuits in than that, and I plan on the need for some 220 circuits in the future for items like an air compressor and a welder. So, one of my questions is, where do I find an appropriate breaker panel for my application?

Also, when I was looking at the panels, some were "main lug" and some were "main breaker," what is the difference? None of the books I have cover this. The "Main Breaker" panels seem to be very similar to what I have on the exterior of my house for my current breaker panel. I will likely need to have this replaced as well, since my main panel is only 125Amp. (I'll have this done by an electrician also-how much should I expect to pay for a panel swap assuming no other major changes are necessary?) Fortunately, it looks like I already have a 200A meter installed.

I'm sure I will have more questions later, but I appreciate any advice I can get for the moment.
 
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#2 ·
Just a wild guess, but if the house service is adequate to run the new sub panel, which you telling me it's on the exterior of the house leads me to believe it might need to be updated as well, but I'd say you'd be in the $500-$700 ballpark. Ask around for some referrals for local electricians, or hit the yellow pages.

You could also put up a bid request thru some of the internet lead services like renovationexperts, service magic, respond. I think Nathan is working on his own deal like that, but I don't think he's quite got it going yet.

Hope that helps a bit. I'm sure we've got some electricians that pop in here now & again that could give you a better idea also. Good luck.
 
#3 ·
Thanks. while I don't particularly care for the fact that the circuit breaker panel is outside (I would much rather have it in the utility room or something), it's pretty common where I live. My house is only 16 years old, so It's not like I am running a fuse box or old wiring or anything, the builder (Ryland homes) just put the service panels on the exterior of the house. The main reason I think I need to upgrade it is because it's a 125 amp panel, and I want to run 100amps to the garage alone! Further, I have thoughts of putting a spa/jacuzzi on the patio, and I know that will most likely require it's own 50 amp service. It's also pretty loaded already with slimline breakers (I think there are a few slots still open though).

I am kind of hoping that the panel swap for the main service will be pretty easy/cheap. I'm hoping someone just has to have the power disconnected by the utility corp, then just move all the old stuff to a new 40/40 200A panel.

something I thought was kind of weird...I called the county's permit office yesterday to see if they allow owners to pull permits or if an electrician has to do so. They stated that my county does not have any codes or zoning restrictions, so they don't issue permits for electrical or do inspections or anything. They told me to check with my HOA and the covenants to make sure, but this seemed really odd to me...has anyone heard of a county doing things like this before?
 
#5 ·
FlyGuy said:
The main reason I think I need to upgrade it is because it's a 125 amp panel, and I want to run 100amps to the garage alone!
Why 100 amps? DO you really need 100 amps in the garage? This is an enormous amount of power to the typical residential garage. 50-60 amps is a typical sub-feed to a garage. If you really need this much that's fine.
There are sub-panels with 12-16-20-24 spaces. For small panels most all main lug panels are 125 amps, while most main breaker are 100. This is fine to use for any sub-feed from 30-100 amps.




FlyGuy said:
Further, I have thoughts of putting a spa/jacuzzi on the patio, and I know that will most likely require it's own 50 amp service.
True. I do agree that an upgrade to 200 amps is the right way to go.



FlyGuy said:
I am kind of hoping that the panel swap for the main service will be pretty easy/cheap. I'm hoping someone just has to have the power disconnected by the utility corp, then just move all the old stuff to a new 40/40 200A panel.
Sorry but this is completely false. A new service will require EVERYTHING from the point of attachment at the top down to the meter pan, to the panel, to ground rods, to a water bond. ALL (except the ground rod conductors) are sized to a 200 amp service.



FlyGuy said:
something I thought was kind of weird...I called the county's permit office yesterday to see if they allow owners to pull permits or if an electrician has to do so. They stated that my county does not have any codes or zoning restrictions, so they don't issue permits for electrical or do inspections or anything. They told me to check with my HOA and the covenants to make sure, but this seemed really odd to me...has anyone heard of a county doing things like this before?
Unfortunately many areas do not require any permits or inspections. The local authourities ultimately have to deal with the consequences of this decision.
 
#6 ·
Speedy Petey said:
Why 100 amps? DO you really need 100 amps in the garage? This is an enormous amount of power to the typical residential garage. 50-60 amps is a typical sub-feed to a garage. If you really need this much that's fine.
There are sub-panels with 12-16-20-24 spaces. For small panels most all main lug panels are 125 amps, while most main breaker are 100. This is fine to use for any sub-feed from 30-100 amps.





True. I do agree that an upgrade to 200 amps is the right way to go.




Sorry but this is completely false. A new service will require EVERYTHING from the point of attachment at the top down to the meter pan, to the panel, to ground rods, to a water bond. ALL (except the ground rod conductors) are sized to a 200 amp service.



Unfortunately many areas do not require any permits or inspections. The local authourities ultimately have to deal with the consequences of this decision.
Well, the lack of permits/inspections would explain the crappy workmanship in the garage. It's not a finished garage, it only has the framing and siding, yet all they did was run romex through the walls...no conduit, and no rhyme or reason to the wiring layout. I kind of think the initial homeowner did the garage wiring himself, and the garage initially came unpowered.

Anyways, I'm still unsure of the main breaker vs. main lug issue for a subpanel. Which do I need to get? I can't imagine getting a main breaker panel for the subpanel because the shutoff/breaker for the garage would be at the MAIN panel, not the subpanel, correct? That leads me to beleive it's the main lug panel I should be getting. But you say that they usually come in 125Amp, and not 100.

I am pretty sure I already have 200Amp service from the city. I put a picture of my meter at:
http://www.geocities.com/justin_peters@sbcglobal.net/Electrical_Pictures/Meter2.jpg

You can look at my main panel and my entire setup at:
http://www.geocities.com/justin_peters@sbcglobal.net/Electrical_Pictures/CBPanel2.jpg
and
http://www.geocities.com/justin_peters@sbcglobal.net/Electrical_Pictures/Setup1.jpg
respectively.

What in the setup picture would you imagine I would need to replace besides just the panel, if I do actually have 200Amp service from the utility company?
 
#7 ·
FlyGuy said:
Well, the lack of permits/inspections would explain the crappy workmanship in the garage. It's not a finished garage, it only has the framing and siding, yet all they did was run romex through the walls...no conduit, and no rhyme or reason to the wiring layout. I kind of think the initial homeowner did the garage wiring himself, and the garage initially came unpowered.

Anyways, I'm still unsure of the main breaker vs. main lug issue for a subpanel. Which do I need to get? I can't imagine getting a main breaker panel for the subpanel because the shutoff/breaker for the garage would be at the MAIN panel, not the subpanel, correct? That leads me to beleive it's the main lug panel I should be getting. But you say that they usually come in 125Amp, and not 100.

I am pretty sure I already have 200Amp service from the city. I put a picture of my meter at:
http://www.geocities.com/justin_peters@sbcglobal.net/Electrical_Pictures/Meter2.jpg

You can look at my main panel and my entire setup at:
http://www.geocities.com/justin_peters@sbcglobal.net/Electrical_Pictures/CBPanel2.jpg
and
http://www.geocities.com/justin_peters@sbcglobal.net/Electrical_Pictures/Setup1.jpg
respectively.

What in the setup picture would you imagine I would need to replace besides just the panel, if I do actually have 200Amp service from the utility company?
Just came back from Home Depot to get some other stuff for an unrelated project. While I was there, though, I looked at the panels. I noticed that some of the Square D panels said they were convertible between main breaker and main lug...this means that I can set it up in the main lug configuration and use it as a subpanel, correct? (Please tell me if I am way off).

Also, in a garage, is there a standard height that electricians like to see receptacles installed at? I know inside residences it is usually at 12", but higher would be more practical in a garage/workshop.

Another question...romex always comes with a white neutral, so if you're installing say, a three way switch or something, the white neutral will ocassionally need to be re-coded as hot with electrical tape or marker. However, since I will be running conduit with THHN, should I use white and re-code to black, or should I simply run two black wires? (Or would you rather see someone just run romex through the conduit?) I'm trying to make my work look as professional as possible without actually BEING an electrician, so let me know how you all like to see things done.
 
#8 ·
I can't say Iv'e seen convertible panels. You really don't want to pay for the breaker if you don't need it.
I'm sure there is a main lug panel that is right for you. As far as these panels go 100 and 125 amps are basically the same thing. Get one in either rating and you'll be fine.

I place rectalces in garages at 48" to the top. This places them at a good height in areas where "stuff" might be places, ie: along the walls.

We re-color the white in NM because two wire only comes with black and white. It is code compliant and is perfectly safe.
That being said, we DO NOT do this with conductors in conduit. This is not code and is not very professional. Also, NM in conduit is slowly being cleared up as a very controversial topic. Bottom line is, whether it is legal or not, not very many self respecting electricians run NM in conduit.
Use conductors, in the correct colors, with a ground, and you'll be fine.
 
#27 ·
I place rectalces in garages at 48" to the top. This places them at a good height in areas where "stuff" might be places, ie: along the walls.
Speedy, when I installed a sub in my garage, I installed two receptacle circuits, one on each north and south walls, not to mention a dedicated one for my compressor (where have we discussed this one on the board?!). Not giving it much thought, I simply set all of the new boxes at 16" above slab. I wish I had done as you advise 'cuz I'm always having to find them behind the sheet goods that I keep stored against the wall. And when I do, I either have to move stuff to get at them or dive behind with the appliance cord in hand to plug things in.:wallbash:

In addition to 2 recepts above my work bench, I installed 3 along each wall, ends and midpoint to make sure that I always had one close. If they're too low and constantly buried though, it sort of defeats the purpose, n'est-pas?.

Great advice from the man!
 
#9 ·
Speedy Petey said:
I can't say Iv'e seen convertible panels. You really don't want to pay for the breaker if you don't need it.
I'm sure there is a main lug panel that is right for you. As far as these panels go 100 and 125 amps are basically the same thing. Get one in either rating and you'll be fine.
Thanks, I appreciate all the info and help. Have you ever seen anyone run a subpanel witha breaker both at the main box (feeding the subpanel) and one at the subpanel itself? (Essentially creating shutoffs at both ends of the feed).

The reason I don't like some of the 100Amp main-lug only panels I have seen is that they tend to not have many spaces, and I'd like the ability to add more circuits later without having to remove the panel and install a different one later. Some of the convertible panels I have seen have more spaces for more circuits. (The convertible panels I have seen are by Square-D. I haven't really looked at too many other vendors).
 
#10 ·
All major brands (SQ D, Siemens, Cutler H, etc) all offer main lug panels with just as many spaces as main breaker. I just purchased a C-H 100A ML panel with 20 spaces. This is a common stock item.
If you go to an actual supply house you will see what is available.

It is no problem to have a breaker in the main and also the sub. Some DIY folks like this better as you can kill power to the panel locally to do work.
It's your call.
 
#11 ·
60 amp service to a 100 amp capable panel?

I have a very similar situation in that I am running a sub panel to my garage. I am going to run off a 60 amp breaker in the main however I too have not found a satisfactory panel with enough spaces other than panels rated at 100 amp or 125 amp. Am I correcty in assuming that I can use one of these higher rated panels if I am only feeding it with 60 amp capable cable? Please help.
 
#13 ·
I have a very similar situation in that I am running a sub panel to my garage. I am going to run off a 60 amp breaker in the main however I too have not found a satisfactory panel with enough spaces other than panels rated at 100 amp or 125 amp. Am I correcty in assuming that I can use one of these higher rated panels if I am only feeding it with 60 amp capable cable? Please help.
Just a fyi, you do know to separate the neutral and ground in the garage if it is detached from the house and all that stuff. As well as the gnd electrode(rod) etc.. If not ask away....
 
#12 ·
Yes. You can do as you want. higher rated panel can feed from a 60amp breaker. I to just finished my detached workshop with i might add loads of help from this forum. I fed out 100amps to my shed. I bought a GE contractor kit from lowes for about 70.00. It came with 6 20amp, 1 30 and 1 50 amp breakers. I had to buy a separate equipment gnd buss, but it bolted right into the box. I fed this with 3 #2 thhn and 8 for eq gnd. Everything went like clock work except the #2 in conduit. that stuff kicked my azz. It had a mind of its own, but we finally came to an agreement :laughing:.

Wired up lights, and ran 3 gfi protected circuits. All is good in my world now. You can do it, just take the time to double check what your doing and DONT work on it live :no:. You'd be surprised how many people do this.
 
#14 ·
Well, now that you brought this three year old thread back to life I see I made a big mistake back then.
I mis-read the OP to say his garage was attached. It is detached. This WOULD require a main breaker, or some other form of disconnect for the remote structure.

So to answer your question, no, it is no problem to have breakers at both ends. In fact, like I said, you do need a disconnect at the garage, so a main breaker is the easiest way to go.
 
#16 ·
I guess I didn't notice the dates but thanks for your responses. The garage is attached and I plan on running about 30 to 40ft of cable for either a 60 or 80 amp. Right now the main panel is 100 amp only (why they did it I don't know) and I plan in the future to run a cable and replace the main panel with 200 amp. From what my utility says the wire to the meter is good to 300 amp. I'm curious on the differences between attached and detached and what I would need to do?
 
#17 ·
Ran 100amp because on older houses that was all they needed. Back then all the gadgets were not in homes like they are today.

Attached means it is attached to your house. Detached is one that stands alone in your back yard etc... Putting it simply :)

Ask this question for grounding purposes. Detached has to have a separate gnd rod etc. but you wont in your case.

SO you are gonna run out of your main panel (100amp) into a sub for this garage? Need to decide on 60 or 80 amp feed (the wire will be different gauge) as well as IF your present service will let you pull that much since it is only 100amps. That will depend on what you will have in this garage in the form of tools etc as opposed to how much you have in the main house as well.
 
#18 ·
Mr. 5oo- What size conduit did you run the #2 in??? I will be pulling three #2 alum with a #8 copper this weekend through a 1-1/4 inch PVC conduit. Do you think it will be as difficult as yours to pull?? Any pointers??? Cyndi
 
#20 ·
1 1/4 is fine Cyndi. Aluminum is stiff but it will pull into PVC fairly easy. Did you get a pulling grip? Make the lead as smooth as you can with tape. Keep the twists and kinks at a minimum while pulling. Pull steady, not jerky. It's fine to stop and rest during the pull. :thumbsup:
 
#19 ·
You would ask me that now lol. If I remember it was 1 1/2. Had plenty of room. I only had to go 30 feet. So it wasnt that bad. what was bad was getting it to turn 90 degree in the LB things I bought. I think yours is primarily straight correct? Suggest getting some of that lube stuff they have for pulling wire. Don't know what it is called, I did not get any due to I only went 30 feet or so.

I know thats not much help, one day ill be like stubbie lol....And just throw out useful info to people :laughing::laughing:

I pulled my wires through the conduit then glued the 2 pieces together. Don't know if this will work in your case. Some advise against doing it that way, but it worked for me

Mike
 
#21 ·
I plan on running #4 copper wire for a 70 amp sub panel, it will be about 40 lineal feet. A couple questions, if I run individual wires in conduit what size ground wire would I need? Also can I run cable (not in conduit) instead? The run is under the house in about a 6ft high crawlspace. I would prefer not to drill thru the rafters but fasten to the bottom of each.
 
#23 ·
John-

I looked at the grip photo that Stubbie sent me. I decided to use the existing #8 wires that are in the conduit to pull the new #2 through as I remove the #8's. Stubbie said to stagger the new wires including the #8 ground with the #2 alum and pull through with one of the #8's that I am removing at the same time. I have two 90 bends one at the main panel and one at the sub panel 120 feet away. I'll let you know how many new cuss words I learn during the process!!!:laughing:
 
#24 ·
John-

I looked at the grip photo that Stubbie sent me. I decided to use the existing #8 wires that are in the conduit to pull the new #2 through as I remove the #8's. Stubbie said to stagger the new wires including the #8 ground with the #2 alum and pull through with one of the #8's that I am removing at the same time. I have two 90 bends one at the main panel and one at the sub panel 120 feet away. I'll let you know how many new cuss words I learn during the process!!!:laughing:
Not only did I say a few bad words, I threw "stuff" around. Even at one time thought about just giving UP on it lol. But the wire and I came to an agreement. Yours will too once you show IT where it wants to go :laughing::laughing:..
 
#28 ·
I ran 10awg to our Sub out in the Garage, and from there, put in a 20amp & 15amp. The 20 for outlets, and 15 for lights. If I ever decide to go with a 30amp circuit, I just have to change out the breaker in the Main, and a short section of 12awg to the box where it exits to the trench.
 
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