Pole Building -- Electrical Question

[psj12]

I used 1/0 aluminum wire to run 125 amp service 96 feet from the meter (direct bury cable). I wired it just like firefighterjim said and it works just fine. Go to http://www.csgnetwork.com/wiresizecalc.html to calculate needed wire sizes.

 

[ray66v]

It is perfectly acceptable here in Ohio! Tell me why it wouldn't be.

If it is a sub panel, it should be properly grounded back to the main panel.

There are some exceptions to this, in some places. However, it is a good practice.

My understanding is: You will bond the neutral, and ground, at the sub, in the 3 wire set up. And you don't bond them in the 4 wire set up.

 

[Inspector507]

It is perfectly acceptable here in Ohio! Tell me why it wouldn't be.

Because the 2008 NEC no longer allows it on a new installation if you're in an area that has adopted that standard.

 

[Pops15]

I used 1/0 aluminum wire to run 125 amp service 96 feet from the meter (direct bury cable). I wired it just like firefighterjim said and it works just fine. Go to Wire Size Calculator to calculate needed wire sizes.

Just because it works doesn't make it safe or legal.
Like Ray says if its a sub panel it needs to be grounded back to the main panel.
Some jurisdictions require a separate ground rod for the sub panel AND tie the sub panel ground rod to the main panel ground or main panel ground rod.

 

[hitekcountry]

Because the 2008 NEC no longer allows it on a new installation if you're in an area that has adopted that standard.

And for good reason Here's why.

The previous version of NEC allowed two grounding options in wiring from a main panel to a sub panel in an out building

First option (4 wires) was to run the two hot wires plus the neutral and a ground in which case ground and neutral WOULD NOT be bonded at the sub panel

Second option (3 wires) was to run the two hot wires plus neutral and no ground in which case ground and neutral WOULD be bonded at the sub panel.

And in both options a grounding rod must be installed at the out building and tied to the ground buss bar.

However the second option was ONLY ALLOWED if there was no other grounding path such as a water pipe or coax cable or anything that would be grounded at both ends, which would create a parallel neutral return path and allow current to flow in the ground wires. NOT GOOD!!

So why was it allowed before and not now? Because some one would wire according to option two which would be perfectly fine, then sometime later install some electronic gear that was connected to power at both ends, as an example I installed a second dish network receiver in the gym in my garage. Now the coax cable provided a ground connection from my house wiring system to the garage which was wired with the second option (3wire) and the neutral then had a parallel path for current to flow in the TV coax cable. Like I said NOT GOOD!!

With the new code this won't happen.

 

[rambler]

It is perfectly acceptable here in Ohio! Tell me why it wouldn't be.

It used to be, but NEC has changed, and only in some rural locations for farm buildings is a 3 wire 220v setup allowed.

Today, most of you will need to install 4 wires: 2 hot, 1 nuetral, and one ground wire to extra buildings as subpanels.

The neutral & ground wire will only be bonded one time at the main service panel. NO WHERE else should these 2 wires be connected together, or it sets up un-safe loops that defeat the whole point of the ground wire and actually make everything much more dangerous. In your lifetime, you hope the ground wire is never ever used; but if needed, it can save your property or life.

But only if it is wired properly.

Many people confused the neutral & ground wires, but they have very different purposes. The ground wire is the round, 3rd plug on a socket, and is a safety device only. The nuetral wire is one of the spade opennings, and is part of the energized circut. They are different, and should remain different.

Both of them do need to be grounded to ground - but only in one place, at the main box.

--->Paul

 

[Diamondpilot]

A cheaper route (since it is a long run) would be running 3 wires (2 hots and 1 neutral) (aluminum) and drive a ground rod at the new building for your ground wire (copper) from the new sub panel. And as SPIKER pointed out, do not bond neutral to panel. (sub panel will require a ground bar kit)

That is the way my barn is done also. We added a hot tub in 2004 that we had pre-wired when the house was built in 1997. The Spa Panel for the Hot Tub Required 4 wires but when it was pre wired in 1997 they only ran 3. We had to go back and snake a 4th #8 wire back to the main house panel and add a ground bar bus in the main panel. I wanted to just drive a grounding rod like my barn had but they said that was no longer acceptable.

Chris

 

[firefighter jim]

Thanks to all for the 4 wire explanation. Still somewhat confused but agree that the latest NEC should definitely be followed. I guess I need a newer code book! Jim

 

[Diamondpilot]

Thanks to all for the 4 wire explanation. Still somewhat confused but agree that the latest NEC should definitely be followed. I guess I need a newer code book! Jim

Yes, things change but the way things were wired using 3 wires and a grounding rod is safe and grandfathered in so I would not lose any sleep over it.

Chris

 

[wroughtn_harv]

I'm building a pole buidling in about two months and plan on running electricity to it before next winter. Would #10 wire be as good as I need and should I run two wires? Here is some more information:

• I plan on dropping in additional breaker in the house fuse box and connecting the pole buidling to the house and putting in a small fuse box at the barn
• The buidling will be about 400 feet from my house
• I will run lights most of the time and a fan in the summer and maybe a tv/radio
• I will also run a compressor and possibly a small table saw and small hand tools and probably a charger for my tractor on occasions.
• No plan to hook up heater as I have a wood buring stove

Is this going to burn up the wires or my house or the barn?

I'm running two hundred and fifty feet of service, 100 amp, to a barn. I'm using 1/0 for the hots and a 6 gauge for the neutral. For four hundred feet I think I would want to talk to the electric company about seperate service with the barn having its own meter.