Ditching with a middle buster (tater plow)

markcg2000 · Mar 9, 2001

Taking into account the loss in the cable, are you attaching to a 60-amp breaker in the source (the house, right?) How much current is "used" in the cable... or does 4-gauge mean this is no issue at all /w3tcompact/icons/wink.gif?
Before I'd discovered the 12-guage, I was running a 5hp compressor, or a small table saw with no problems. Well, I mean, they still run with no problem, but I'm nervous /w3tcompact/icons/smile.gif.

mark

WVBill · Mar 9, 2001

Mark: Right. I'm using a 60 Amp breaker in the house to feed the circuit. There's a 100Amp panel in the barn to split out to the branch circuits. The 100 Amp breaker serves only as a local cut-off switch.

#6 Wire is sufficient for 55Amps but, as you point out you need to consider the voltage drop (how much current is "used" in the cable) also. With #6 wire you can get 55 Amps but will only have maybe 100Volts out at the barn - very bad for motors, etc.

That's why I went up a size to #4 wire. It has a lower voltage drop in a cable that long.

There are calculators at this web site http://www.electrician.com/ that you can plug in the length of the run and the expected current to determine the recomended wire guage.

They also have a very good forum at http://www.electrician.com/wwwboard2_secure/wwwboard2.html where you can get advice in detail on any DIY electrical projects you may have. That's where I got a lot of good advice on wiring the barn.

WVBill · Mar 9, 2001

Harv:

I just used "phone wire"
Hmmm... I haven't finished covering up the ditch yet. I don't really plan on using the computer in the barn, will standard (light tan) phone wire work OK for just voice? I looked and couldn't find direct-burial phone wire at Home Depot or the like...

markcg2000 · Mar 9, 2001

Thanks very much for the sites.

I'm in the phone industry, so that's something I do know about /w3tcompact/icons/wink.gif.
I guarentee the standard tan wire meant for the inside of your house will fail if buried - unless you live in a 0% humidity area. The phone company uses "b-buried" cable... actually has a wax/grease inside the outer insulation to help prevent the water damage. That's a little expensive, but there is a reason the phone company uses it! A good conduit would do the job, too; just make sure it's truly sealed at each end. Should be able to find it at places like Anixter, Simcona, Greybar or any place listed in the yellow pages under cable supplies. Pulling cable through conduit that far is a royal pain, so you might want to price the differance between conduit (+ your time) vs b-buried.

mark

RobS · Mar 9, 2001

Hey Mark, is there any issue (EMC/RFI etc.) with putting phone lines in the same conduit as 110/220VAC?

I'm not planning on doing this anytime soon, but as long as we have an expert on hand... /w3tcompact/icons/smile.gif

WVBill · Mar 9, 2001

Thanks, Mark.

I'll hold off on backfilling the ditch 'till I find the right wire.

I must admit that I cheated when I put the electrical conduit & wire in. I laid out the wire and slipped the conduit over it from one end one piece at a time, gluing them as I went. Once again, I know that is not according to code but there are no enforced codes here and I honestly could not think of a reason not to do it that way.

markcg2000 · Mar 9, 2001

Yep, there is. If you really want to do this right, you install 4-pair, CAT5 data wire inside a conduit. That's overkill for the voice, but perfect for the data. Same places sell that stuff, usually in 500' or 1000' foot boxes for around 10 - 15 cents per foot.
I like these guys

Having said that, the real killer is arcing - motors, flourescents, welders, etc. 110-120 volt AC doesn't produce much RFI at all, but there is no way I'm going to go through the hassle of pulling phone/data wire ANYWHERE and not put in the CAT5.

mark

markcg2000 · Mar 9, 2001

... I cheated when I put the electrical conduit & wire in.

Uh, that's how I would do it /w3tcompact/icons/wink.gif.
One trick that may come in dang handy someday - run a cord along with the wire, leaving enough exposed in the house to reach back to the barn again - in other words, a 150' foot run would need a 300' cord. That way, if you ever want to pull something else (co-ax, fiber, whatever) you just tie it to the cord just as it comes out of the conduit in the house, go out to the barn and pull. The excess in the house goes along for the ride, the cord is in the conduit still with the "new" excess in the barn. Beats having to dig up and lay another conduit, eh? Same argument holds when decidiing the diameter of the conduit - I'm going to lay 2", even though 1" would carry one pull of power and one pull of data with room to spare.

mark

Harv · Mar 10, 2001

Bill -

Guess I'm a little late getting back to this thread, but it looks like Mark has answered your questions way better than I could.

As for where I got my direct-burial cable -- it was from a neighbor, who in turn, got it from a phone company field service guy. He had a couple hundred feet of the stuff that was off the spool and cluttering up the back of his truck. He was only too happy when my neighbor offered to take it off his hands.

Doesn't help you very much, does it? /w3tcompact/icons/crazy.gif

Anonymous Poster · May 14, 2001

Where did you buy your middle buster and what brand is it? I want to do the same thing but bought a plow. It just doesn't seem to do the trick. Your pix a really good at showing how well the middle buster does.

Thanks Tim Pratzer