What do Run to Sub Panel

[BMacD]

Hey Guys,
Have been reading lots of different threads, but have come up with lots of different solutions so i'm wondering what would be best for my Situation.

I'm planning on running 100A(Probably overkill) off my main panal to the Detached Garage Sub Panel. Garage to the back of the house is around 32 Feet, and from the back of the house to the Main Panel is another 32 Feet. It'll be buried underground between the house and garage, and then ran in the Basement Ceiling to the Panel.

AL or Cu? And what size? Thanks

 

[pattenp]

For 100A I recommend AL Mobile Home Feed 2/0-2/0-2/0-1/0 for the under ground feed. See link:http://www.southwire.com/ProductCatalog/XTEInterfaceServlet?contentKey=prodcatsheet15
When transitioning to inside the house switch to SE 1/0-1/0-1/0-2. See link: http://www.southwire.com/ProductCatalog/XTEInterfaceServlet?contentKey=prodcatsheet273

 

[BMacD]

Thanks, If I were to run conduit in the basement could I run the MHF all the way to the main box instead of running a j-box to splice the connections?

 

[pattenp]

NEC does not allow USE to be used for interior wiring and states it is to be terminated at the exterior. Which means you would need to have a junction box and transition to SE in to the house. The SE would not have to be in conduit. If you did carry the MHF all the way to the main panel you would have to put it in conduit. I guess the grey area here is, is MHF considered to be USE as the code may suggest. You really need to ask your local electrical inspector if they would allow the MHF to run all the way to the main panel.

I think this affirms that you can't use the MHF inside. Read this:http://www.ecmag.com/?fa=article&articleID=9229

I'm still a little grey on the MHF if it's conductors are RHW or RHW-2 rated as to whether you can run it inside. I don't know if RHW is fire resistant. I've never run MHF inside, based on my understanding I switched to SE once going inside.

 

[pattenp]

Splicing in a j-box is ok if the j-box has its volume marked. The problem is the j-box isn't going to be large enough to make the splice because of the code requirement to leave enough wire to work with. You will probably need to use a 12X12X8 box or an 8X8X4 may be as small as you can go.

 

[BMacD]

Thanks!

 

[Falcon67]

I used USE-2 and have been told AOK for inside use. I assume that is because the cable uses all insulated conductors and the insulation is upgraded (from USE) to flame retardant.

The NEC table switch for cable from service entrance to feeder cable is a mystery to me LOL. The way the utility treats the service entrance, you'd think that'd get a de-rate to force a larger cable.

 

[pattenp]

This makes sense to me but I just can't find any official write ups that say it can be installed inside.

I used USE-2 and have been told AOK for inside use. I assume that is because the cable uses all insulated conductors and the insulation is upgraded (from USE) to flame retardant.

The NEC table switch for cable from service entrance to feeder cable is a mystery to me LOL. The way the utility treats the service entrance, you'd think that'd get a de-rate to force a larger cable.

 

[pattenp]

Well I just found this info which says (if I'm reading it right) USE-2 is not suitable for interior use. I give up.

See this link: http://www.iaei.org/magazine/2007/0...-use-cable-be-used-inside-for-premise-wiring/

 

[Falcon67]

LOL - as long as my local is OK with it, I'm happy. I have some of the wire left over, I just can't remember the other tags on the the wire. It's spliced at a J-Box under the eve on the shop side of the house, so if something changes here or a future inspection says "hey, you can't do that" I only have to change out about 55' of cable.

Supposedly, per Southwire, the cable meets UL 854 and UL 44. UL 584 refers to UL 44
"[FONT=arial,helvetica]1.5 Type SE cables that are not marked with conductor type letters or are marked with conductor type letters alone ("XHHW", "RHW", or "RHH OR RHW" not followed by "cdrs" or the like) have insulated conductors that do not comply with the Thermoset-Insulated Wires and Cables, UL 44, horizontal flame test."

So the inference is - to me anywho - that if the cable meets 44, then it meets the flame test requirement. I'll find out what's on the cable.
[/FONT]

 

[BMacD]

The more I think about it, I really don't need 100A at the garage...I may just run 60A or 70A as it will be plenty for me. The Wire for that load will be easier to work with as well

 

[pattenp]

I think you'll be okay with the 60A-70A. That way you can use AL MHF 2/2/2/4 and SE 2/2/2/4.

 

[slacker garage shop]

For inside you would run SER cable and for 100 amps you only need #1 AL.

 

[pattenp]

For inside you would run SER cable and for 100 amps you only need #1 AL.

You should have a caveat to the #1 AL. #1 AL SER is okay for 100A if not run within insulation. If running within insulation such as in an insulated wall then #1/0 would be needed.