Junction Box for 1 AWG

[Redhotrod]

Hi everyone, I got a question for the pros here, I am running electrical out to my pole barn in the works and I have 2 sections (6 wires total) of 65' 1 awg with (1) 6 awg ground I was able to get through my work that we were going to scrap. My 1st question is I will have an outside run in 1 1/2" pvc for 40' between the barn and house, and in the basement to my panel is 35', which I will use 1 1/2" EMT. What size junction box do I need for 1 Awg? I was thinking of putting the junction box inside the basement where the pvc will meet the EMT, or would it be easier to just use a 100 amp disconnect box there instead? 2nd question is if I only have 100 amp service to my house, is it ok to make my Garage service 100 amps too with this wire run? I do not need 100 amps out there now, but just future proofing the idea since I have the more expensive part available. For now I will be powering lights and outlets (120v/20a) , possibly a small mig welder (240v/50a), eventually a lift (240v/20a) and a Bridgeport milling machine (240v/30a).

 

[nehog]

Exactly what kind of wire is it? What are the markings on it? It may well not be approved for burial for example.

 

[madosta]

Splicing will be fun for your hand workout.

Pics? Wire markings? Copper/aluminum? Are they individual wires or attached together? You say 3 wires, you will need 4 wires from your house panel to your garage panel.

 

[Redhotrod]

It is (3 wires 2 hots/1 neutral) THHN copper 1 awg, with a 6 awg thhn copper ground wire that will be in conduit. 1.5" pvc underground to garage (40'), 1.5" EMT in the basement (35'). Now I need to join the pvc and EMT together and since my wire sections are too short, what is the best way to connect them together, a junction box I understand will need to be fairly large, I just do not have the knowledge of how small it may be. and instead of wire nutting, this I am sure will use a terminal block, I am just thinking it may be cheaper to just use a disconnect box for the junction.

 

[pattenp]

Why not just use PVC conduit the whole run. Where the splice needs to be done use a 12"X12" PVC J-box. You drill your holes in the J-box using a hole saw and buy the glue in fittings for the conduit connections. Use splice/reducers or Polaris connectors for doing the splices.

 

[Redhotrod]

Good idea patten, I will use pvc all the way with the jbox and I already have a terminal block, so that'll do. Thanks for the idea!

 

[madosta]

Now I'm not an expert, but I think it needs to be THWN if in the ground. Would it work, probably.

 

[Redhotrod]

With my 100 amp house service, is it acceptable to put 100 amps in the barn?

 

[pattenp]

With my 100 amp house service, is it acceptable to put 100 amps in the barn?

It's okay. If you overload the whole shebang it will just trip the main breaker.

Also the THHN most likely also carries the THWN rating. If by some off chance it's only rated THHN then it cannot go in conduit underground.

 

[Redhotrod]

So I am getting lucky so far. My 1 awful wire is double labeled thhn and thwn and I was able to get all my PVC conduit for 20% off. Maybe luckier if my buddy has a 8x8x4 deep PVC Junction box. Will that be acceptable for joining the 4 wires together?

 

[Redhotrod]

So I am getting lucky so far. My 1 awg wire is double labeled thhn and thwn and I was able to get all my PVC conduit for 20% off. Maybe luckier if my buddy has a 8x8x4 deep PVC Junction box. Will that be acceptable for joining the 4 wires together?

 

[pattenp]

I think you need a box bigger than 8X8.

See SIDEBAR: Minimum Size Rules in 314.28 and splices and see Fig A .......

http://ecmweb.com/code-basics/2011-nec-revisions-boxes-conduit-bodies-and-handhole-enclosures