What type of feeder/wire for a sub panel?

[allinon72]

Never thought I'd get such a confusing mixture of responses when I searched for what the correct type of wire is needed for a 100a sub panel. I need to add one from my main panel in the garage, almost directly below in the basement in an unfinished utility space. Call it a roughly 25 foot run from the main panel to the sub panel location. From what I've read, I can't use 2224 SER unless I go down to a 90a breaker, but this seems to be the only option that doesn't require conduit. The other options seem to require conduit, and out of those it seems like 2 gauge XHHW wire is the preferred option? I'm less concerned about cost and more concerned about doing it the right way considering it's going to be expensive either way.

Someone just tell me what to run lol.

 

[PCustoms]

They sell 1113 SER.....

 

[u2slow]

You need #1 alum for 100A unless you choke it down to 90A (if you care about code.)

Direct burial cable comes in many sizes. Check a supplier since box stores have limited selection.

 

[allinon72]

You need #1 alum for 100A unless you choke it down to 90A (if you care about code.)

Direct burial cable comes in many sizes. Check a supplier since box stores have limited selection.

I see - then I would route it in what size conduit?

 

[sparky 1971]

Just run the #2 SER and be done with. You can get a 90 amp breaker at an electrical supply house or order it online. 10 amps isn't going to make a difference.

 

[u2slow]

I would run cable, and not bother with conduit other than some sleeving for short bits that need mechanical protection ( if applicable).

 

[pattenp]

SER comes in 1-1-1-3, not 1-1-1-2.

 

[mike93lx]

Is this sub in the attached garage or detached?

I agree, 90a is the way to go, either way

 

[PCustoms]

SER comes in 1-1-1-3, not 1-1-1-2.

My bad.

Still holds true he can jump up a size if he wants SER and full 100A.

At $6.53/ft vs. $4.64/ft not sure I'd pay for it though.

 

[allinon72]

Is this sub in the attached garage or detached?

I agree, 90a is the way to go, either way

From attached garage to basement.

 

[mike93lx]

From attached garage to basement.

SER needs to be treated the same as romex (nm-b). If it is in a spot where it is subject to damage, you need to protect it (conduit, a chase, in a wall, etc). If that isn't an issue, ser is the ticket.

I would do 2-2-2-4 AL

 

[allinon72]

SER needs to be treated the same as romex (nm-b). If it is in a spot where it is subject to damage, you need to protect it (conduit, a chase, in a wall, etc). If that isn't an issue, ser is the ticket.

I would do 2-2-2-4 AL

I'm leaning that way, with a 90a breaker and call it good. The entire run will be in a wall.

 

[wyliesdiesels]

I highly doubt youll need 100a. Get #2 SER and a 90a breaker and be done with it.

 

[Snapped-off]

I highly doubt youll need 100a. Get #2 SER and a 90a breaker and be done with it.

2-2-2-4 Al would this work? Similar situation to the OP. I'm wanting to add a new 100a sub panel in the garage to replace the existing 30a screw in fuse box currently installed. ~40' run. 90a in the main would be fine.

 

[sparky 1971]

2-2-2-4 Al would this work? Similar situation to the OP. I'm wanting to add a new 100a sub panel in the garage to replace the existing 30a screw in fuse box currently installed. ~40' run. 90a in the main would be fine.

That's it. If you can't find a 90 amp breaker just use a 60. You can always upsize when the supply chain gets straightened out. You'll probably never need to though. I've got two sub panels fed by #2 aluminum.

Edit: that's underground wire. If the garage is detached it will work as long as the wire is dual rated. The easiest thing to use is #2 MHF though. If the panels are both inside, no underground, attached garage like the panel in this thread, you want #2 SER cable.

My bad for not clicking the link. I was watching a re-run of the Carol Burnette show with Tim Conway and wasn't paying attention.

Southwire 500 ft. 2-2-4-6 Black Stranded AL MHF USE-2 Cable 30163001 - The Home Depot

Southwire Aluminum USE MHF Service Entry Electrical Cable is designed to connect mobile homes to a supply of electricity.

www.homedepot.com

https://www.lowes.com/pd/Southwire-Southwire-2-2-2-4-Aluminum-Ser-Service-Entrance-Cable-By-the-Foot/4294349

 

[Snapped-off]

That's it. If you can't find a 90 amp breaker just use a 60. You can always upsize when the supply chain gets straightened out. You'll probably never need to though. I've got two sub panels fed by #2 aluminum.

Edit: that's underground wire. If the garage is detached it will work as long as the wire is dual rated. The easiest thing to use is #2 MHF though. If the panels are both inside, no underground, attached garage like the panel in this thread, you want #2 SER cable.

My bad for not clicking the link. I was watching a re-run of the Carol Burnette show with Tim Conway and wasn't paying attention.

Southwire 500 ft. 2-2-4-6 Black Stranded AL MHF USE-2 Cable 30163001 - The Home Depot

Southwire Aluminum USE MHF Service Entry Electrical Cable is designed to connect mobile homes to a supply of electricity.

www.homedepot.com

https://www.lowes.com/pd/Southwire-Southwire-2-2-2-4-Aluminum-Ser-Service-Entrance-Cable-By-the-Foot/4294349

It's detached. I should've specified. I was having trouble finding SER locally by the foot. The box stores show it unavailable in my area.

 

[sparky 1971]

It's detached. I should've specified. I was having trouble finding SER locally by the foot. The box stores show it unavailable in my area.

The stuff you posted is URD and some of it can't be run inside unless it has the dual rating. Just go with the MHF. It can be direct buried and run inside, but has to he in conduit when not in the ground.

SER can't be run underground anyway.

 

[wyliesdiesels]

2-2-2-4 Al would this work? Similar situation to the OP. I'm wanting to add a new 100a sub panel in the garage to replace the existing 30a screw in fuse box currently installed. ~40' run. 90a in the main would be fine.

Since its detached just run MHF.

You will need conduit indoors

 

[laser3kw]

when my garage was wired the electrician talked me out of 90amp main and installed 60 amp main breaker (in house panel). I haven't had any problems. I have all the normal stuff, air compressor, 40 t8 tube lights (Bulbs), hand grinders etc. My amp clamp meter shows normal draw no where near 60 even with air compressor kick on.

 

[theoldwizard1]

... I can't use 2224 SER unless I go down to a 90a breaker, ...

People make to much about the size of a breaker feeding a sub-panel ! If this is cost effective, go with it. It is highly unlikely that you would ever trip the 90A breaker anyway unless there is a dead short in the wire.

 

[theoldwizard1]

when my garage was wired the electrician talked me out of 90amp main and installed 60 amp main breaker (in house panel). I haven't had any problems.

Unless you are having a "welding party" running multiple welders at the same time, you never will !

Worst case scenario would likely be mini-split, plasma cutter and compressor. Even then, just turn off the mini-split for the 5 or 10 minutes you're using the plasma cutter.