Running wire to detached garage!

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  #1  
Old 12-27-10, 11:34 PM
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Running wire to detached garage!

Hey all. I just bought my first house 2 months ago and finally have my own garage! This is my first post, and as I'm learning all kinds of things about wiring, I've run into some questions. So here it is: I have wired up 4 circuits (not hot yet). 1 for all the outlets. 1 for the main lights. 1 for the work bench lights. And 1 for the fridge and garage door. I have them all feeding into a 100 amp subpanel w six spaces (12 circuits). I am using 20 amp circuit breakers in the subpanel for each circuit. I have 2 spaces
on the main breaker box on the house available and plan to use a 60 amp breaker to feed this subpanel. Running the wire in the ground isn't an option. I have to run it in the air. So I have a few questions:
1) what type/size wire do I need to use as the feeder from the main to the subpanel? It's about a 40ft run. Van I get away w 10-3?
2)since it's in the air what type of conduit to use?
3)is a 60 amp breaker at the main breaker box siufficient?
4) lastly and a bit of a weird question. If I spray paint any exposed wire in the garage (by the way I used 12-2 romex) will that damage the wire any???

Thanks for all the knowledge and I look forward to more posts and way more research on this site. Who would have known ur first house would b so much work ... And money. Thanks again

J
 
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  #2  
Old 12-28-10, 02:11 AM
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Originally Posted by Whoknows View Post
Hey all. I just bought my first house 2 months ago and finally have my own garage! This is my first post, and as I'm learning all kinds of things about wiring, I've run into some questions. So here it is: I have wired up 4 circuits (not hot yet). 1 for all the outlets. 1 for the main lights. 1 for the work bench lights. And 1 for the fridge and garage door. I have them all feeding into a 100 amp subpanel w six spaces (12 circuits). I am using 20 amp circuit breakers in the subpanel for each circuit. I have 2 spaces
on the main breaker box on the house available and plan to use a 60 amp breaker to feed this subpanel. Running the wire in the ground isn't an option. I have to run it in the air. So I have a few questions:
1) what type/size wire do I need to use as the feeder from the main to the subpanel? It's about a 40ft run. Van I get away w 10-3?
2)since it's in the air what type of conduit to use?
3)is a 60 amp breaker at the main breaker box siufficient?
4) lastly and a bit of a weird question. If I spray paint any exposed wire in the garage (by the way I used 12-2 romex) will that damage the wire any???

Thanks for all the knowledge and I look forward to more posts and way more research on this site. Who would have known ur first house would b so much work ... And money. Thanks again

J
Ok ., As soon I read it I did see couple red flags allready fling up fast.

Here what you have to be aware with the codes I will fill you in along the way.

First thing first .,

For any 120 volt circuit all them have to be GFCI protected there is no extemps anymore if you are on 2008 or later Code cycle { unless written in local code stated diffrent }{ I do not know which area you are in once I know which area then I can able tell you the diffrent code verison }

For 50 amp overhead run you will need quadplex cable for overhead span and you will need minum of 6-6-6-6 but 4-4-4-4 is proper with Alum cable verison and you will need proper split bolt to splice them together.

From the breaker box to the first outside connection if not in the conduit you can use the SER or 4 conductor NM cable { note all subpanels the 3 conductors set up are not allowed anymore for a while } you will have to use #6 Copper or #4 Alum cable that based on 50 amp breaker but if you really want to go with 60 amp breaker then you have to bump up the conductor size up to next size bigger that is written in the code and we do follow proper conductor size chart. { I never trust the big box store chart due they always give ya wrong info on the chart }

DO not try to run with 10-3 with 60 amp breaker that is serious issue that will catch on fire before the breaker will trip { I have see it before }

DO you have a main breaker in the subpanel if not you will have to install a 60 amp breaker and backfeed it { there is a hold down bracket to hold the breaker and it will serve as your disconnet location }

Most case spray paint useally don't bother it too much but becarefull where you run the NM in exposed walls { some area they can get really picky on this } normally I just run a conduit up the wall to point where there will be no damage above 8 feet level or higher if required.

I useally wired in with either MC cable or in Conduit so most garage I work on it very rare for me to use the NM unless it will be enclosed with insluating and with drywall or pretty thick paneling to prevent any damage.

Oh yeah ., You will have to sink two ground rods at subpanel location keep the rods 6 feet apart and you will need to bring out #6 Bare conductor for this purpose and Keep the netural and ground conductor seperated in subpanel useage and some case you will have to buy a ground bussbar due some of them don't have it.

I know there will be other guys will chime in with their recomendations as well so please follow the codes and proper permits I know many inspectors are getting strict with it.

Merci.
Marc
 
  #3  
Old 12-28-10, 11:53 PM
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Been looking at the forums. So I got the gfci outlets. Can I run aluminum 2 Gauge for the hots. Alum 4 gauge for the neutral. And copper 6 Gauge for the ground? All w a 60 amp breaker in the main box? All in metal conduit o course. This is what I've found from reading other posts. But wanted to make sure didn't miss anything.
Thanks all
j
 
  #4  
Old 12-29-10, 12:24 AM
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Originally Posted by Whoknows View Post
Been looking at the forums. So I got the gfci outlets. Can I run aluminum 2 Gauge for the hots. Alum 4 gauge for the neutral. And copper 6 Gauge for the ground? All w a 60 amp breaker in the main box? All in metal conduit o course. This is what I've found from reading other posts. But wanted to make sure didn't miss anything.
Thanks all
j
For the overhead yes you can use the 2-2-2-4 quadplex the #4 will be bare so that will be used as ground as far for netural some will have a white strpe and some by the numbers of ribs or other marking.

Few case you may see red stripe as well.

For the conduit itself you don't need to go that big a conductor you can get by with #6 THHN/THWN's full 4 conductors but you will have to buy a split bolts or polairs connectors to tranlated the connections I know you will need one set at the house side and again other set for garage side.

Make sure you keep the overhead wire at least 10 to 12 feet above the ground level so you may have to put up a persescope or mast up to raise it higher unless you have two story house then it can able taper down to the garage side.

Keep in your mind the #2 AWG will not fit in most of the 60 amp two pole breakers that why I mention it right away.

But hang on tight there may be other guys will comment more as well.

Merci,.
Marc
 
  #5  
Old 12-29-10, 09:03 AM
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Since quadraplex may be over kill for this and there is a problem with fitting to the breakers because of wire size you might want to consider sunlight resistant #6-3 UF. You could use steel cable as an overhead messenger and fasten the UF cable to that to support it.
 
  #6  
Old 12-29-10, 09:55 AM
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Originally Posted by ray2047 View Post
Since quadraplex may be over kill for this and there is a problem with fitting to the breakers because of wire size you might want to consider sunlight resistant #6-3 UF. You could use steel cable as an overhead messenger and fasten the UF cable to that to support it.
How unprofessional looking and ugly! Quadplex looks waay better! You may also be able to go up to an 80amp breaker with 2awg , as it is used for 100amp services.
 
  #7  
Old 12-29-10, 03:49 PM
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Marc. Couple more questions. I measured today and from main box up to attic and to garage looks like about 75ft
r u saying I could run 6-6-6-6 from main in conduit to the attic then run 2-2-2-4 for the overhead into my subpanel?
Will the 2-2-2-4 be to big to fit in my hot ins in the sub?
I have read that u r not to use conduit for the overhang but should run indiv wires. Is that correct? If so indiv wires would look ugly is there another option?
Thx again
j
 
  #8  
Old 12-29-10, 05:26 PM
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With a 60 amp breaker from the main to a 100a subpanel, can't he just use 6AWG, or does the subpanel rating of 100A require 2AWG??

ALSO, which temp rating should he be using: 60C, 75C, or 90C?
 
  #9  
Old 12-29-10, 05:29 PM
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Thank u for addl questions. Didn't know about temp rating

j
 
  #10  
Old 12-29-10, 08:05 PM
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Hold on a minuite before we get any more confusing here with this matter.

I do understand that the OP did mention overhead run due he can't buried the conduit / conductor for some reason so let leave as it is.

Now let get this matter stragihten out.

From the breaker box to the first attachment point for overhead span if you use the 60 amp breaker you have to run this in either 3/4 inch or one inch conduit and use #6 AWG THHN/THWN { I will expain the rest why in a bit } from there to overhead run you can use either quadplex overhead cable or use the UF cable with messeager support wire*

then just reverse it when you get to the garage side the same thing.


Now If you going with UF cable route then you have to drop the breaker rating to 50 amp per NEC code due the UF cable is only rated for 60C it will have diffrent ampacity what the THHN/THWN will sized at 75C however I know the 90C is there but only used for derating purpose so leave that out of this equation here.

Two most common methold is 60 or 75C rated cables the UF and NM and SE et SER cable are only rated at 60C while THHN/THWN and quadplex are rated at 75C so it will have diffrent ampacity ratings there.

Whoknows there one suggest you can use is 6-3 NM with ground for inside portion of house until you poke it outside with a junction box or weather head on one of two and make sure you leave a drip loop to keep the water from wicking up to inside part.

otherwise the SER cable will suit this purpose but you have to bump up one side due majtory of the SER cable are useally alum size unless you run stright 2 AWG then you can get by with 90 amp breaker if you want to.

Justin.,

The #2 alum SER or quad can handle much as 90 amp due this is a feeder not servcie entrance that will change a bit on that one so watch that part.

Tac .,

If the OP did have 100 amp rated subpanel that is not a issue the key item will be sized by conductor size plus materals that will affect the rating at the main load centre location so if he used #6 THHN/THWN he can use 60 amp breaker but if used 6-3 NM with ground no then it have to drop down to 50 amp breaker as I mention above.


That why I want to get this matter straight out before it get out of the hand.

Merci.
Marc
 
  #11  
Old 12-30-10, 10:36 PM
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Will something like this b an appropriate choice:
http://www.platt.com/CutSheets/Generic/Xhhw%20alum.pdf

j
 
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