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100 amp sub panel

BobMeyer58

New member
Joined
Feb 17, 2013
Messages
1
I need to run wire for a 100 amp sub panel to a detached shop. It will run about 50 feet in the attic of my house to the back yard. Then down to be under ground 25 feet to the sub panel on the shop. What wire do I need for both? Is there a 2-2-2-4 copper or do I need 4 seperate wires?
 
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Chuckster in NJ

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Joined
Jan 26, 2010
Messages
2,370
Location
Hunterdon County NJ
I need to run wire for a 100 amp sub panel to a detached shop. It will run about 50 feet in the attic of my house to the back yard. Then down to be under ground 25 feet to the sub panel on the shop. What wire do I need for both? Is there a 2-2-2-4 copper or do I need 4 seperate wires?
Look this up in the NEC……. "IF" you are asking a question like this, it is proof that you are not qualified so call a professional.
 

manwithtools

ALLIANCE MEMBER
Joined
Aug 24, 2015
Messages
14,713
Location
Lebanon, TN
Not a very nice way to respond to a new (since 2013) member with a single question about his electrical install. I'll agree it's a bit vague, but maybe with a little more information we can help hm select the right solution for his feed to his shop.

OP, tell us more about what you have going on in your shop / project.
 

My Old Tools

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Jun 4, 2014
Messages
5,494
Location
Hamrick Lake, TX
If you put your subpanel on a 90 amp breaker, you can run AL 2-2-2-4 mobile home feeder wire. Now all the experts can come tell you why you can't. Will you require a permit and inspection?
 
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Chuckster in NJ

Well-known member
Joined
Jan 26, 2010
Messages
2,370
Location
Hunterdon County NJ
Not a very nice way to respond to a new (since 2013) member with a single question about his electrical install. I'll agree it's a bit vague, but maybe with a little more information we can help hm select the right solution for his feed to his shop.

OP, tell us more about what you have going on in your shop / project.
"IF" you were an electrical contractor who served an apprenticeship, obtained his license and now pays insurance you would understand why I don’t tell anyone how to do an electrical job like this over the internet.……. Nobody sees what materials are being used, the job site conditions or his knowledge of electric.

BTW! As an electrical inspector I have seen (and failed) many "homeowner Joe jobs" where the owner spent hours searching the internet for how to advice.…… I have also seen some really bad electrical jobs performed without an inspection that caused a fire or a new homeowner who inherited the electrical nightmare on a foreclosure.
 

u2slow

Well-known member
Joined
Nov 20, 2011
Messages
3,634
Location
BC
Dont know where you are located, but in my jurisdiction we run ACWU cable end-to-end. #2 for 90A.
 

zimman

Well-known member
Joined
Mar 2, 2014
Messages
2,624
Location
Mark Twain National Forest
Not a very nice way to respond to a new (since 2013) member with a single question about his electrical install. I'll agree it's a bit vague, but maybe with a little more information we can help hm select the right solution for his feed to his shop.

OP, tell us more about what you have going on in your shop / project.
Some days around here are like Facebook, but shittier. LOL
I've been a Mod before on some other forums and it ceases to amaze me why folks just don't scroll on by.
Zim
 

cpakalolo

Well-known member
Joined
Mar 30, 2026
Messages
113
I need to run wire for a 100 amp sub panel to a detached shop. It will run about 50 feet in the attic of my house to the back yard. Then down to be under ground 25 feet to the sub panel on the shop. What wire do I need for both? Is there a 2-2-2-4 copper or do I need 4 seperate wires?
Yes, your wire will come as four in one. Usually. Some SE will come wrapped as an assembly for direct burial. Put in some PVC conduit of your choosing and go. Just general info. The ground is usually one size smaller and sometimes the neutral is smaller, but I don't like to shrink the neutral. In your sub panel, the neutrals and grounds are kept separate. You still need a good ground rod attached to your subpanel. Use the ampacity tables and use 75 degrees for the specific type of wire written on the wire's jacket. The tables are per 100 feet so, at 75-80 feet you can use the numbers as you see them without length deration.
 
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