Installing Electric To The Barn

Anonymous Poster · Jan 27, 2003

I wasn't suggesting that MTW should be run. I was only stating the difference in MTW and THHN. I use both at work in there respective places. I myself ran 4-#3 THHN in 2in PVC conduit for 100A service into a sub-panel.

Ray (10yrs. industrial electrician)

kcbarnes · Jan 27, 2003

Can I ask is it consumers energy or one of the "BPU's"?

Pks · Jan 27, 2003

RayS,

I don't quite follow the statement: "...wire size for 50 amps shall be no smaller than 6Awg (55A)" Is this statement for the context of a supply/feeder run as opposed to a branch circuit?

My electric drier uses 10/3-wg on a 30 Amp 230v circuit breaker. And my welder manual (which is not yet installed) is requesting 10/3-wg 230v 100 Amp breaker, if the run from the box is less than 87 feet.

Anonymous Poster · Jan 27, 2003

Had to jump in on this, One thing not mentioned is rodents, with the wire direct buried the gophers think its some juicy root and gnaw on it and cause it to leak to ground, or just plain blow up wire and themself. I have had this happen 3 times on an 1100' run to my well, very tough to trace out. I wish I had put it in conduit now, but at the time I thought it was ok 2' deep. Also what is important in sizeing the wire is the voltage drop, it should be 3% or the wire will overheat, for long runs the resistance of the wire must be taken into account. to get 20amps at the end of 200' run without overheating wire you would need to use #6 thhn, for 50amps #2 both copper. also running romex in conduit is a no no because of the overheating. Motors can run on a higher voltage drop because of there intermitent use,3% voltage drop is for general purpose,lighting loads. A 50amp sub is the way to go most of the time,compressors,welders,saws,etc. Also very cheap ($15 home depot) considering time and effort

bky · Jan 27, 2003

I would agree with inspector057run pipe in the ground (pvc is cheep) also your allowed 360dirgrees in bends before you have to hit a pulling point.
Also it doesn’t matter if the wire is rated at 90 degrees because most connections are rated at 75 degrees
I seen more wire burnt up or broken in the ground than I care to have seen and had to dig it up to fix.
Pipe is the only way to go.
Also I think they should change the code to reflect that. Just my option

MossRoad · Jan 27, 2003

You might be allowed 360 degrees in bends, but chances are you aren't gonna be able to pull it over 270 degrees, even with pulling lube.

Inspector507 · Jan 29, 2003

With the right size pipe, and the right amount of wire lube, you'd be surprised at what we've pulled.

MossRoad · Jan 29, 2003

I agree with you completely, however, the right size pipe, and the right amount of wire lube are two things most people don't use... /w3tcompact/icons/laugh.gif

Wingnut · Jan 29, 2003

I agree with you completely, however, the right size pipe, and the right amount of wire lube are two things most people don't use... 
especially since the right size pipe is the next larger pipe than you used and the right amount of wire lube is about a gallon more than you have available
/w3tcompact/icons/laugh.gif /w3tcompact/icons/laugh.gif

MossRoad · Jan 29, 2003

especially since the right size pipe is the next larger pipe than you used and the right amount of wire lube is about a gallon more than you have available

You got that sooo right! /w3tcompact/icons/laugh.gif