Pole Barn feeder - need input

[MagKarl]

New pole barn, approx. 200 ft run from house panel. I have 320A service to the house. Would like 100A to the barn. Will be doing the grunt work myself, uncle is retired electrician and will help. Work will be permitted and inspected.

Wire sizing calculator says 1/0 Al required. Was thinking I'd get 800 ft of XHHW, and run it from a new 100A breaker in the house panel, through buried PVC conduit to a 100A panel in the barn.

I have Cutler Hammer CH panels and can get a 100A breaker for the feeder that will accept 1/0 wire. Plan to get a 100A CH main panel for the barn.

My tight spot is I made the mistake of stubbing out a 1 1/2" conduit from the house when I built it, should have gone 2". It's under a sidewalk now, so I'd prefer not mess with that. Conduit fill charts say max of 4 1/0 conductors in 1 1/2" PVC, but I will switch to 2" for the new portion of the conduit run.

Does this general plan look reasonable and NEC compliant?

 

[Max Plavec]

Are you using schedule 40 or schedule 80 PVC, is its 40 your in the clear if it's 80 you'll have to run 1 AWG copper. If your budget permits I would run copper regardless. Best of luck be safe and use plenty of wire lube.
Ps if you go with Aluminum use Noalox.

 

[unsinkable]

How is pipe stubbed out of house, straigt or with 90's in it ? LB ?

 

[Aceman]

I would run:

2- 1/0 hots
1- #2 neutral
1- #4 ground

You increased the size of your "hot" wires so your ground wire must also increase in size. Second, if you have 240v loads in your pole barn, there is no reason for a full sized neutral. I almost never pull full size, I always drop down one or two sizes. #2 AL will carry 90 amps of neutral load and it's extremely unlikely you'll ever see that much with a reasonably balanced panel. On top of that, it's cheaper and reduces pipe fill.

 

[ladderwell]

This sounds like my pole barn. Total run of wire 184'. AL 1/0, 100 amp sub panel in the shop. Permitted and inspected. Sch. 40 2" conduit. I'm just outside of Eugene, OR and I know OR and WA codes are pretty much the same. Sounds like you're on the right track.

 

[MagKarl]

Existing 1 1/2" conduit starts at an LB on the house wall, below the panel.

Conduit is Sch. 40 PVC.

I'm not sure I want to downsize anything yet. Where can I find out more about downsizing the neutral and ground conductors? I haven't found much for code references, mostly opinions.

 

[Aceman]

Equipment grounding conductor size:

Table 250.122
250.122(B)

Grounded(Neutral) conductor sizing:

225.5
225.8
220.61

 

[MagKarl]

Thank you Aceman, I'll look those references up.

 

[MagKarl]

Finally had a weekday off and made it to the electrical supply house for the feeder wire.

Picked up 3 lengths of 1/0 and a #4 for ground. Need to see what else I might need such as clamp/lugs to land on the bus bars.

I'm pretty excited about the idea of not stringing cords out to the barn to do any work.

 

[McFarmer]

Shoot, I was going to recommend wooden feeders in a pole barn.

 

[Eriehunter]

Finally had a weekday off and made it to the electrical supply house for the feeder wire.

Picked up 3 lengths of 1/0 and a #4 for ground. Need to see what else I might need such as clamp/lugs to land on the bus bars.

I'm pretty excited about the idea of not stringing cords out to the barn to do any work.

That should pull in a 1 1/2 conduit nice, as long as you use lube and don't have too many bends between pull points.

The 1/0 should be what is called compact conductor so it will take less space in the conduit than a copper conductor of the same size.

 

[MagKarl]

I need some help on the hardware side of things, bushings and strain relief mainly.

Where I exit through the bottom of my main panel in my garage with my 4 leads, I need some sort of bushing, what is recommended here? The run in the wall from the bottom of the panel down to the LB is about 16" in the same bay. It's covered with drywall and hoping not to have to cut that open.

For the subpanel in the barn, I'll have 2" PVC coming up into the bottom of the panel box with a male threaded fitting and a lock nut. Does this need strain relief? I've never seen it where conduit connects to a box, but I'm not an electrician.

 

[MagKarl]

Does conduit have to be continuous from panel to panel, or am I ok in my garage wall cavity between the LB and main panel? They are ~16 inches apart in the same stud bay but behind drywall. I'm assuming that is not an issue.

 

[pattenp]

Does conduit have to be continuous from panel to panel, or am I ok in my garage wall cavity between the LB and main panel? They are ~16 inches apart in the same stud bay but behind drywall. I'm assuming that is not an issue.

If you are talking about individual single conductors then yes it needs to be in conduit from panel to panel. Even when the conductors are run within a wall cavity.

 

[MagKarl]

****! Thanks pattenp, that's going to add some siding and drywall work.

Open to suggestions here, I have a panel in 2x6 wall, and an LB on the outside of the wall below the panel in the same stud bay. How to connect from panel box to conduit?

I'm thinking either move the LB up higher on the outside wall to come into back of panel, or add a junction box from the interior side under the panel so the existing LB could come into that from the back, then have conduit between the new junction box and the panel bottom. Any input appreciated.

 

[pattenp]

Bring LB up and feed through the back of panel. Or use jbox and change over to SE cable for the run in the wall up to the panel.

 

[MagKarl]

I have power! One 20A circuit with a GFI plug and a single bulb light, and a 50A welder plug. It's a start.

Question on the welder plug wire, I have a spare 50A range cord that I cut the jacket off of, it is fine stranded copper. Can the individual conductors from this cord run from breaker to plug, or is this the wrong type of wire?

 

[pattenp]

Once you remove the jacket it is not to code because the wire has no identifying marking. Also cord is not suitable for permanent building wiring.

 

[MagKarl]

Thanks Pattenp. I thought that may be the case.