Undermeasured wire need for shop

[Earl]

I've been reading posts here for a while now and have learned quite a bit so far. Probably over used the 'Search' feature to the point that it may not work for others. But....
Looks like my first post here will be owning up to a mistake and to ask for advice on possible future use of the wire I purchased for the feed to the shop. I messed up when measuring the distance from the shop to the house and came up a few feet shy of what I needed. It is (hope I'm using the correct terminology) #2 aluminum. Got 4 long pieces that I know I can't return but thought maybe they can be used for providing power to something else in the shop as I get into the interior wiring. Hate to just toss it up on the shelf and let it sit.
Shop won't have a lot in the way of big electrical draw machinery. Will have 2 outlets for 220v for a future welder and/or table saw. Other than that just the normal 110v outlets and lighting.
Thanks for any direction you guys can give me. Oh, before anyone says to, I already gave up my measuring privileges.
Earl

 

[rockwithjason]

lol, happens to the best of us. maybe you can cut in a jbox somewhere and use it to contain a splice. that way you can still use the wire and just get the additional length needed.

 

[mrb]

I always way overdo it with wire length. Learned the hard way one time when pulling a long run and the ends of the wire disapeared into the conduit. I would rather throw away 50 feet of wire than be 1 foot short.

Perhaps you can put it for sale on craigslist. At least it was only #2 AL, and not something more expensive.

FYI, you dont need 4 pc of #2 AL, your ground can be smaller.

Tell us what exactly you are doing and you will get a ton of advice. We have saved several members here alot of trouble, expense, and caught potential problems before they got installed.

 

[Earl]

The basics for the shop are:
24x24
Will have my woodworking tools and some of the auto work stuff out there. Most of the auto work will be done in attached garage as I don't like the possibility of picking up a greasy tool while working on a wood project.
Will be wiring for the welder which, when used will most likely be used just outside the roll up door. Easier for me to wire it out there rather than in the garage.
Shop is 37 feet from the house (from elec. panel in house to panel in shop. (I didn't account for the fact the 1 1/2" pipe is 24" under the ground, hence an extra 2 dang feet on each end of the run. Bleh.)
Wife was talking about expanding the shop and adding on to it in the near future to possibly make it around 35x40. Her idea not mine, I just agreed real quick. So more lights and receptacles.
I don't foresee any major projects that will draw a major amount of juice from the house. Had a guy from power company come out to give us a quote on running a new supply to the shop rather than coming off the house. $2500.00 was way too much. He told us while he was there that he was the one that pulled the wire for our house and that we could support 400 amp panel and split 200 each for house and shop. Also an expense we can't see. We have gas heat and a gas water heater so there are 2 of the main electrical draws out of the loop. So we're going with 100 amp supply to the shop.
Dang that was a ramble, but there it is.
Earl

 

[mrb]

FYI you have to breaker #2 AL at 90 amps, cant use it for 100. Need #1 for 100 amps.

I would put the wire for sale on craigslist or whatever and just buy new wire (with a few extra feet)

Sounds like you have a good plan. Post pictures for us as youre doing it

 

[walrus]

A mile too long is better than an inch to short. The electricians motto

 

[Falcon67]

I did a similar thing with the new house service. Bought 26' of #2 copper for the run up the mast, then figured out the mast was too short by about 2'. I gave the three too short pieces to a guy in my car club that is a commercial electrician. Not enough qty to recycle, so at least it gets used and not tossed.

 

[Fast Orange]

Where did you buy the wire? If you bought it at a supply house,many times if it's long enough to resell,the manager will alow a return for credit towards the new wire-at the supply house I worked at,anything over 50' would be taken back,sometimes with a restocking charge(25%).If you bought it at a big box,I'm afraid you're out of luck.
Most electricians ,after figuring conduit or trench length,plus any riser height and allowance to get to the terminals,will add another 10% for a fudge factor.
I'd recomend going to the #1 also-meets all codes and you be using a 100A c/b,instead of a breaker that may or may not be in stock.

 

[VHF]

You could use the #2 AL to feed a subpannel on the opposite side of the shop. Don't know if your layout would benefit from a second pannel, but on a rectangular building having a subpannel on the opposite end from the main pannel can be handy to keep branch circuit runs short. Reduces voltage drop if your high current loads (welder, compressor) are close to the subpannel.

 

[Earl]

This is what I've read from my research. (wish I could copy/paste this but here goes)-

No part of this feeder from the breaker in the dwelling to the disconnect form in that detached garage may be rated in ampacity that is smaller than the overcurrent device {breaker or fuse} protecting that feeder in the dwelling’s panel. Article 210-19 & 215-2 & 220-3 & 220-10 & 240-3 & 240-6 If you install a 60 amp breaker 240 volt in the dwelling, then you may use a 6/3wGrnd UF copper cable from that dwelling’s panel to that garage disconnect. If you install a 100 amp breaker 240 volt in the dwelling, then you may use a 2 awg four wire URD aluminum cable from that dwelling’s panel to that garage
Heh, copy/paste is my friend

 

[mrb]

look at an ampacity chart. 75deg column for #2 AL is 90 amps. Furthermore URD cannot enter a structure unless it is dual listed XHHW. (you may see XLPE on it, which is a type of plastic not a wire type)

 

[Earl]

Just went out and wrote down the info off the wire the electrician told me to get(this is off the wire I pulled through the conduit that is too short, haven't purchased replacement yet):
E39406 W 2AWG AA - 8000 AL Type USE-2 OR RHH OR RHW-2 600V (UL)
I found a Table in the NEC book I have (Table 310.16) is this the correct table? And does the cable I have fall under the 90 deg column? My hat is off to you guys that have learned this info over the years and have been able to keep up with it and I'm almost leaning toward finding the electricians I gave a hard time to in the Coast Guard and apologizing to them.Give me A/C & R and Diesels.
Thanks for your patience with me.
Earl

 

[mrb]

youre good on the wire type, USE-2 is underground, RHH/RHW is a listed wire type.

You cant use the 90deg column since the lugs you will be terminating on will only be 75deg. I would just breaker it at 90, i dont think you will miss the 10 amps.

You dont need 4x #2. You can use 3x #2al and a #6 copper for ground, or 3x #2al and a #4al for the ground. Save you a couple bucks and will be easier to pull.

 

[Earl]

thanks for the info. Just need to pull the cable back OUT of the conduit, roll it up and commence pulling the new stuff through after I go get it. Dropping a size on the ground might make it a bit easier on the pull although it wasn't too bad the first time.
Earl