Main line to garage

[1966chevelle]

I will be running power from my house (200 amp) to my garage (100 amp). A friend of mine offered to sell me some 2 2 2 4 URD for .50 a foot. I measured from the house to the barn and the distance is 100 feet. That is just laying the tape measure flat on top of the ground. With that measurement I assume I need to add 20 feet for under ground up to the fuse panels on both ends. My questions are is this wire the right size for my application and does the 20 foot extra length sound correct? I don't want to buy it and then find out that I am a few feet short. Thanks

 

[AntonLargiader]

For 50 cents per foot, buy extra. You don't need to nail the length perfectly beforehand.

Installing the cable will be one of the last steps, so you can mock up each end with some old garden hose if you want before you cut and purchase. Run a section through your conduit from the bottom of the trench to the termination point, then pull it out and measure. Add everything up, add another 5 feet, and you should be good.

 

[1966chevelle]

The problem is he has another guy wanting to buy it now so I need to tell him today how much I want. That's why I'm trying to figure this out. The other major thing is if this wire is ok to run at this distance and still get my 100 amp's.

 

[cj7jeep81]

Is the wire aluminum or copper? If aluminum, you'd need to breaker it at 90 amps. Personally, at that cheap I'd buy 150 feet to be extra safe.
I'd much rather spend and extra $20 and have too much. Considering this stuff is about $1.50 a foot normally, you'll still save a ton.

 

[brewchief01]

If it's URD it probably isn't rated to be used indoors, you would have to transition to a different wire at each end to go inside.

Sent from my XT1254 using Tapatalk

 

[wyliesdiesels]

Need to find out what the exact insulation ratings are. If its not RHH/RHW rated then it cant go indoors.

URD does not have fire resistant rated insulation.

 

[pattenp]

One way to identify it as URD is the three #2's will be all black and the one #4 will be black with a yellow stripe. When URD has four conductors, three are phase conductors and one is the neutral conductor. It is designed for power distribution so there is no EGC.

 

[1966chevelle]

This is what he has. It does have a yellow stripe on it. According to Home depot it is Aluminum but is rated for direct burial ? I know very little about electrical so I am really confused now.

http://www.homedepot.com/p/Southwir...ded-Al-Quad-****-URD-Cable-55417399/205001803

 

[wyliesdiesels]

This is what he has. It does have a yellow stripe on it. According to Home depot it is Aluminum but is rated for direct burial ? I know very little about electrical so I am really confused now.

http://www.homedepot.com/p/Southwir...ded-Al-Quad-****-URD-Cable-55417399/205001803

Yes that is AL URD rated for direct burial. Its primarily used by PoCos for distribution as Pattenp pointed out above.

Nothing really to be confused about. Its not rated for indoor use. If u wanted to buy it u would have to transition to a different cable type on the outside of the building in a large junction box to be code compliant.

U also said u wanted 100a. That cable wont do 100a.

What do u plan on running in the garage?

 

[ard]

OP. Just so you know: "transitioning to a different conductor" means:

Run the URD up into an outdoor rated box. Mount box on exterior. Run a different cable from this box into the building. Splice cables with split bolts/clamps, wrap and insulate (or equivalent)

Cost is a $8-10 for a box, a couple of connectors/clamps, split lots. Maybe $40 total for one at each end? You will need to buy different wire for the interior portions, so this cable is only 'good' or the 100 feet in the ground. If you are saving $1 per foot, that is $100- minus whatever the transitions cost.

90A is pretty close to 100.... Should be good for almost any 'garage' .

But personally I'd just run something I don't need to box and splice... For the $60 savings.

 

[1966chevelle]

Yes that is AL URD rated for direct burial. Its primarily used by PoCos for distribution as Pattenp pointed out above.

Nothing really to be confused about. Its not rated for indoor use. If u wanted to buy it u would have to transition to a different cable type on the outside of the building in a large junction box to be code compliant.

U also said u wanted 100a. That cable wont do 100a.

What do u plan on running in the garage?

I will be running a 60 gallon compressor, 220 welder, 220 plasma cutter, and your normal lights and wall outlets for hand tools. We do a lot of fabrication but it is very rare that we run all 3 big items at the same time. My dad has a 100 amp service to his shop and we have never overloaded the service. I figured if I have the capability to have 100 amp service I might as well take it.

 

[1966chevelle]

Thanks everyone for the help. I greatly appreciate it.

 

[CNGsaves]

Just do the "GJ standard" and put in MHF Al 2-2-2-4 in conduit end-to-end and be satisfied with 90A. No splicing or junction boxes and not trusting someone's old wire. Also, you'll never overpower 90A in a one-man shop, so the "need" for 100A really isn't there.

 

[revamped]

Just do the "GJ standard" and put in MHF Al 2-2-2-4 in conduit end-to-end and be satisfied with 90A. No splicing or junction boxes and not trusting someone's old wire. Also, you'll never overpower 90A in a one-man shop, so the "need" for 100A really isn't there.

This is exactly what I did and I have 24 circuits, 3 panels, 6 220 drops with 50a breakers. Internally I ran NM6-3 from the 1st panel to the other two subpanels and added the rest of my circuits there since it was cheaper to do it and I needed the 6/3 anyway for the welder and RV circuits. All on a 90a breaker at the house.

I would have to be welding (54a) plasma cutting (24a) while cooking a burrito in the microwave with all the lights on all at the same time to trip the 90. Not likely to ever happen!

Electrical Inspector loved my setup but told me I separated too many circuits and could have done it cheaper... I just looked at him like... is this your f'in garage?