Want to add 230V outlets to my barn

woodlot · Nov 18, 2005

Mwood - I just want to add one thing. The figures I gave in my post above will keep you under a 3% voltage drop. The longer the run the greater the voltage drop. Keeping things under 3% will help keep your expensive tools from going *&(^(* on ya. I think others may have forgotten to consider this important aspect of your electric service.

wire size helper - check it out

BobReeves · Nov 18, 2005

( BobReeves, explain how the 40amp breaker is to large for #6 wire? also I think thhn is good to 90c )

First post in this thread says the barn is fed from a 50 amp breaker.

ericbx · Nov 18, 2005

bob the light bulb just went on. you are talking that the 50amp breaker is to big for #6 wire in the main panel because of the long run should be a 40amp breaker right? but you are also saying its ok to run a welder on a 40amp breaker in the sub panel in the barn right?

ericbx · Nov 18, 2005

Bob I used #8 (copper) THHN with a 30amp breaker at my main panel to my sub panel in the barn. My run is 130’. How does this sound to you. Also does this mean I could run a 60amp 240v circuit in my sub panel(one 30amp double pole breaker)?

Keoke · Nov 18, 2005

Hi folks, it is ok to connect neutral and gnd wires to the same bar at one panel only, usually the main. On all sub-panels you must have a separate insulated neutral bar, without grounding screw, for the neutral wires. On the pic of the barn sub-panel, not sure, but it looks like neutral (white wires) and gnd wires are in the same bar.
Another point, it's looks like the blk wire with yellow stripe is going from house to barn as a combo neutral/gnd wire.
In the barn box you would move this wire to your non-grounded separate neutral bar along with all the white wires. The braided 6/0 gnd wire in same hole as blk/yellow wire should be a gnd wire going to a gnd rod, rebar stub or a metal cold water pipe at barn.
Best to do all wiring to code as insurance companies have a way of bailing out when they find an openning.
One question, whats the big wad of tape covering up in the barn breaker box?

cheers,

LarryD · Nov 18, 2005

One question, whats the big wad of tape covering up in the barn breaker box? 

I'll bet that under all that tape you'l find one of these, it's a split bolt used to splice the nuetral 'cause it was too short.

BobReeves · Nov 18, 2005

If my old memory is working at least when I last checked local code, it was something like....

14ga 15 Amp Breaker
12ga 20 Amp
10ga 30 Amp
8ga 40 Amp
6ga 50 Amp
4ga 70 Amp

That should be close.... These numbers are assuming appliances in the house with 20 to 40 foot runs. Due to the added resistance of the wire in a long run (150 feet) it is best to down size the breaker a bit. A short at the end might not trip the breaker if the resistance of the wire (length) is high enough and you will have a 150 foot heating element (read smoke).

On the other hand my welder (48 Amp input rated) is on a 40 amp breaker because that is what I had. However I have never used the full 230 amp setting on the welder and probably never will so a 40 amp breaker is working fine.

The new run (150 ft) to my shop is 2/0 Aluminum on a dual 100 amp breaker in a 200 amp box at the meter. If I remember code says I could use something like a 175 Amp breaker with 2/0 aluminum but I am comfortable with the 100 amp breaker knowing a short in the shop will trip the breaker.

SPIKER · Nov 18, 2005

I see many post which with the info given were incorrect.

the photos cleared up a lot of the miss conceptions and problems.

you stated you have #6 ALCORE wire, (alum wire) not good for 50 amps at the distance for sure. (not near my code book so can't give the recent code alowances but I belive that would only be good for 30 or so amps now. I also didn't notice if any "No-OX" Anti-Oxident coating was used on the fittings of that alum wire.? (goowie looking stuff to keep the alum wire from corroding & lower the heating problems with alum wire.)

the incoming mains are only good for a SERVICE of 50 amps @ 240 VAC but can give you 100 amps @ 120 volts but will trip if either leg uses more than 50 amps... (typically this is refered to as a 50 amp service though & not the sticker which you see and is what the panel board is rated at not what you're service drop is rated at, for that you should go and read the info on the meter.... now to get 100 amp service normally you have to have a 100 amp breaker installed.

other wise the sub panel in the barn can have a doubble pole 220 volt breaker installed but don't fool you're self & think you can get 50 amps in there...

like others stated call a licenced electrician & get them to go over it and mark things correctly and for future referance... once a home owner messes with the service the insurance company starts smileing... /forums/images/graemlins/crazy.gif

ericbx1500 · Nov 19, 2005

Spiker, I used #8 (copper) THHN with a 30amp breaker at my main panel to my sub panel in the barn. My run is 130’. How does this sound to you. I did the work myself and a electrician told me to bond my neutral and ground bars at the sub panel? My neutral and ground are bonded at my main panel as well.

mwood · Nov 19, 2005

Spiker:

I was wondering if anyone noticed the Alcore (AL Wire) when I posted that. Seems logical what you say. Also, there does appear to be gooey stuff on the posts where the aluminum is attached so I think I'm okay there.

I talked to an electrician friend at work today. He said he'd be hesitant to put anything greater than 40A on that long of a run. He did mention that the pictures I showed him indicated that it was done correctly as far as the install goes.

So it looks like I'm going to have a decision to make here soon.

Thanks for all the help. I'm going to make sure I do this in a way I feel is safe and that I'm comfortable using.

Mark