[vsheetz]

I have a pole barn with a 12x48 shop. I plac ed a 100 amp sub panel in the shop. I have a 200 amp main panel at my home. The distance between the two is approx 150 ft. After checking copper prices I am seriously considering using aluminum as a feed. Will 1/0 aluminum be sufficient. I understand that i will need 2 hots, a neutral, and a ground because I will also have a phone in the shop. Could you all please give me some input on this set-up. I had planned on using 1 1/4 conduit also. Thanks

Having a phone has nothing to do with it - two hots, neutral, and ground are required.

 

[Jxl062643]

Should the 1/0 aluminum get me 100 amps at 150 ft.

 

[Techy]

:yes:

1/0 AL is fine.


http://www.electecinc.net/vdcalc.pdf

 

[WillK]

Having a phone has nothing to do with it - two hots, neutral, and ground are required.

I think he was talking in terms of conduit fill perhaps?

Shouldn't the phone or whatever go in seperate conduit because he's going to have signal interference problems?

And I have a 100 amp panel in a garage that's 30' from the main panel, but I've been using 50' wires and ending up taking around 5-10' off each run. I'm using 1/0 even though it's oversized for my panel. #1 would be fine for me. With the extra length 1/0 should keep you covered.

As for conduit size, I recall that 1/0 feeder is okay for 1-1/4" conduit. I used 2" for my underground conduit run, it goes through a long radius elbow at each end to a conduit body on top of that, from there it goes inside to a junction box and then it goes up to the panel through 1-1/2" conduit.

I have to say it was heavy work pulling 1/0 through the 2" conduit run. Even my short 3' long runs of 1-1/2" weren't easy. Legally you can use 1-1/4" but I'd go larger just for the ease of pulling cables.

 

[Jim Port]

He was saying he was running a 4 wire feeder since there was a phone line back to the other building. Before the NEC used to allow 3 wire feeders if there was no other metallic path between buildings.

 

[vsheetz]

He was saying he was running a 4 wire feeder since there was a phone line back to the other building. Before the NEC used to allow 3 wire feeders if there was no other metallic path between buildings.

aahh, thx :thumbsup:

 

[kbsparky]

1¼ conduit is way too small for such a long run. While it may be Code compliant, you will have much difficulty getting those wires into such a small conduit.

For that kind of distance, I'd recommend using 2" conduit -- it will be well worth the additional material cost, when you factor in the ease of installing the conductors. You don't want to be penny-wise and dollar foolish on this one.

 

[Jxl062643]

Thanks guys , I have read alot and really want to do this project myself. One other question. The Ground bar in the subpanel looks to small to accept the aluminum wire. Is their a adapter that needs to be placed. From what I understand I need two hot wires, a neutral connected to the neutral in the subpanel, and a ground connected to the ground bar in the subpanel. Also will place 2 -8 ft ground rods At the subpanel. If I use 1/0 for the hots and neutral what size do I need for the ground. Thanks, Jamey

 

[kbsparky]

#4 Aluminum or #6 copper would be sufficient for grounding a 100 Amp sub-panel, fed with a #0 AL wire.

As for the lug size, check to see if its rated for a #6 or #4. You may not need a lug adapter.

 

[Wiscbldr]

My two cents.. get a building permit for the electrical work. Hire an electricain to do the proper wiring. Contact your local electrical utility for the final hookup, especially if theres additional metering.

If you do it all yourself, call up the local utility first before any trenching if putting the service underground. (contact diggers hotline).

But I'd lean towards hiring a professional to do this, or at the very least, I'd contact my local electric company and talk to one of their electrical service engineers about proper wiring, conduit, grounding, runs, hookups, metering, etc.

Depending on the distance from your padmount, you may want to tap into the padmount in order to go to a seperate 200 service vs running back from your house.

 

[WillK]

Thanks guys , I have read alot and really want to do this project myself. One other question. The Ground bar in the subpanel looks to small to accept the aluminum wire. Is their a adapter that needs to be placed. From what I understand I need two hot wires, a neutral connected to the neutral in the subpanel, and a ground connected to the ground bar in the subpanel. Also will place 2 -8 ft ground rods At the subpanel. If I use 1/0 for the hots and neutral what size do I need for the ground. Thanks, Jamey

You were talking about pulling 1/0 individual conductors were you not? Like KB says, your wire size isn't as large as 1/0. I used #4 copper from my panel to my ground rods and had no problem getting it into my ground bar.

Now for my subpanel feeder in the house, I used 2-2-2-4 SER cable and put it on a 60A breaker, the #2 aluminum needed a larger lug on the neutral bar. You can get these at the big box store where you find the service panels. There are a couple stiles that give a larger attachment which you screw into the neutral (or ground) bar.

 

[WillK]

My two cents.. get a building permit for the electrical work.

For the OP and anyone else taking on similar projects:

If you've ready my posts, I'd still endorse pulling a permit - even in spite of my inspector being the way he has been. And I'd also endorse hiring a pro if you're able. If you have a pro do the whole thing they would pull he permit, if you're doing some of it you might still want them to pull the permit and work out what you can do to help but let them take the lead.

When I get through my project, I'm going to be pretty happy to be able to just stick to the relatively straightforward branch circuits from here out.

 

[Jxl062643]

Thanks for all the replys you guys have been very helpful. This is something I have been studying on for over a year and really want to do it myself. I plan on renting a trencher this weekend and am trying to get everything in order. If i place 3 -- 1/0 aluminum for the hots and neutral can I pull a #6 bare copper wire in the same conduit for the ground.

 

[kbsparky]

You can use a #6 bare if you want to, although I would not recommend it.

Use a #6 THHN/THWN conductor, and mark it with green tape on the ends.

It will pull into the conduit much easier.

 

[SD515]

Can't re-color a #6 in conduit. #6 insulated has to be green or green with yellow stripes.
I agree though...an insulated conductor will pull much easier.

 

[Jxl062643]

Thanks guys . I have the subpanel figured out . Two hots to breaker, neutral to neutral bar, ground to unbonded ground strip. then a # 6 copper from ground bar to (2) 8 ft ground rods. Right???? Now at the main panel is the neutral and ground bonded or isolated. Thanks for all the help.

 

[SD515]

Ground bar in your sub-panel gets mounted to the tub, thus bonding it to the tub. In the sub, the neutral and grounds are isolated from each other. The neutral bar should already be mounted on an isolated, plastic stand. Do not use any bonding screw, strap, bar, etc. that may have come with the panel. If they’re installed, remove them.

At your main panel, the necessary bonding between the neutral and ground should already be there. You shouldn’t have to do anything else in the main panel.

 

[WillK]

Yeah, should be able to get #6 THHN in green at the big box stores, they'll have 500' spools or you can get the length you want cut from a spool.