Temp power at Pole Barn Site

[extrakt0r]

During the construction of my home I knew I was going to be building a pole barn in the near future. I ran 4/0-4/0-2/0 AL wire about 400 feet to the site of where the pole barn will go. My plan is to have 100Amp service in it when it gets built.

Inside I have 2x200Amp Panels. I have the loads broken out into High and Low. For example the left panel has all the high load items (A/C, Oven, Fridges, etc.) everything on the right panel is low load items (lights) with the exception of my 60Amp breaker for battery backup system.

My plan is to somehow terminate the 4/4/2 wire to the right panel, but I know I cant do this directly. I am not opposed to paying someone to do this. When I built my house I had someone set the panels and I did everything else.

I know you cant get a breaker to support that size of wire, so I would need to go to some sort of disconnect and then out to the barn.

I would like a simple 20Amp outlet at the barn for my electric fence for my new garden, and something I can use for power during the construction of my barn.

Any ideas would be great...

 

[hr3]

Should I or shouldn't I,, Sure why not .. You have a couple of problems you should sort out first..

If you look at your panels you will notice that there is 4 wire coming in from the outside.. I would assume you have a 400a switch on the outside with 2 -4/0 4 wire feeders going to the panels.. This is good and a nice job,, Now any further panels after that ouside switch has to have 4 wires,, I only see 3 wires in your pipe.. I could be wrong,, but it looks like 3..

The second problem would be the URD 3 wire inside the building ,, If the cable has "USE or USE2" only and no other ratings it's not allowed inside the building,, NEC 338.12B...

Other than that you have an easy situation with the wire size and the termination of them,, If your interested just pm..

 

[ironnut]

First off, I am not a licensed electrician, also I am not familiar with the electrical codes that are enforced in your area.

But that won't stop me from offering suggestions.

First a few questions. What size are the main breakers (the ones at the top) in each panel? Enlarging the photo left me guessing 100 amp or 200 amp.

Which of the two panels is fed from the power meter? That panel would be your primary. The second panel would be a sub panel from the primary.

From which panel are you going to connect the feed to the pole barn service?

Most newer residential power feeds are 200 amp. In some cases large homes will have larger, but 200 amp is pretty common. 4-0 aluminum is commonly rated
for 200 amp although some jurisdictions require the next size up. So the 4-0 aluminum wire is certainly sufficient for 100 amp service.

Many local electrical codes in recent years have been modified to require 4 wires for a sub panel, 2 hot wires, a neutral, and a ground. Your pole barn service will be a sub panel and
I suspect will require a fourth wire. A licensed electrician from your area can advise you of that.

A 100 amp two pole breaker should be available for your electrical panel. It will occupy 2 adjacent slots in the panel. I don't know about a 200 amp 2 pole breaker fitting in the lower area.
4-0 wire is not going to fit into the lugs of a 100 amp breaker so some kind of transition connection will be required, e.g. 4-0 spliced to 1-0 aluminum and the 1-0 into
the breaker. The general rule for electrical work is that you must protect the weakest link, so it is normally acceptable to use the smaller wire as long as
the breaker's rating is equal to or lower than the amperage rating of the smallest wire (or device) in the system.

An auxiliary box of sufficient size may be useful to transition between the 4-0 aluminum to the smaller 1-0 wire. Wrestling 4-0 wire in the confines of your electrical
service panel is not a trivial exercise. Again a qualified electrician can tell what size box is required to house the splices between the 4-0 and 1-0 wire.

At the pole barn you will need another service panel. In the past these have not been terribly expensive. You may need to buy one with a 200 amp service rating to make it
relatively easy to to connect the 4-0 wire into the main breaker. At that point a 20 amp breaker can be inserted into the new service panel in the pole barn and
a 20 amp outlet connected. I am not sure that the code permits simply connecting a 20 amp outlet by it self to the 4-0 wire at the pole barn (no main service breaker).
If connecting a 20 amp breaker to the 4-0 wire in the pole barn is allowed, the breaker inside of the panel in your house that is feeding the pole barn would have to
be a 20 amp breaker (protect the weakest link).

A lot of words, hopefully something of it is useful.

gordon

 

[extrakt0r]

I pulled the permit under 2008 NEC which says 3 wire with ground at pole barn is ok according to the inspector. But I can easily pull a 4th as I have several open conduits exactly for this reason.

My inspector said the wire is ok in the house only for "a couple feet" to the disconnect box as long as its in conduct and then is fire rated into the main panel. He said that is standard around here even if it isn't 100% correct via NEC. He said "a couple feet" is not the same as indoor wiring

Either way I will not do anything to put my family at risk. I am thinking it might be to much effort to do this before the barn is built. Making a panel outdoors watertight sounds to be more trouble than its worth...

To answer your question I have 400amp into the house each panel is 200 and wired directly to the exterior meter box.

 

[hr3]

Then your ok .. The local inspector has the last word even over the code,,

What I would do then is in your basement I'd put a 10 by 10 pvc box on your conduit and splice on a piece of #2 ser to go to your panel.. I use the Burndy BIT connectors . http://ecat.burndy.com/Comergent/burndy/product/BIT250 .. Tie the bare ground into the panel but just leave it coiled up in the pvc box.. The reason I would use the ser is so you have a covered neutral to match your URD wire,, Leave the wire a bit long in your panel so you can temp. splice a smaller wire onto it for your temp. outlet . Then put a 2 pole 20a breaker in the panel for the time being.. You got me so far ???

Now outside I'd put another 10 by 10 box on the end of your pipe.. " You will need one to drop the wire size again" but for now you can mount a 2 gang waterproof box on the back side of it bring the wire from the outlets into the bottom of the box,, " You can use this hole later for your ground rod wire".. Install 2 GFI outlets and use the Burndy connectors to connect to your 4/0 wire,, and you should be ready to go...

 

[yelbike]

The above post is clear as mud to me but bang on when I re-read it.

 

[hr3]

The above post is clear as mud to me but bang on when I re-read it.

Sorry... It's so easy doing the work but It's hard for me sometimes getting it across how it's done ..