Service Entry Cable

armyguy · 12-28-2010, 12:41 PM

I built a workshop a couple of years ago but I did not wire it at that time. I don't spend a lot of time out there but I do want to put in a couple of lights and a small heat and air unit. I am wiring my workshop with a 50A service. I need to run around 120 feet of service entry cable and I need to know if #6 copper Direct Burried cable will suffice.

I do plan on running a 220v 50A service with #6/3 w gnd. I have a GFI 50A service disconnect already installed.

Saturday Cowboy · 12-28-2010, 01:11 PM

this is a little short on information. How ever #6 copper is fine for 65amps(75deg).

you will need a ground rod, disconnect/6handles, service calc, 4wire

Saturday Cowboy · 12-28-2010, 06:19 PM

copy from duplicate thread. Service Entry Cable

Quote:

Originally Posted by armyguy

I am wiring my workshop with a 220V/50A service. I need to run around 120 feet of service entry cable in total from my meter base to the workshop.

I already have a 220v/50A disconnect and about 40 feet of 6/3 running from my meter base to my deck which would get me within 80 feet of the workshop.

I need to know#6 Direct Burried cable will suffice. I plan on splicing the additional 80 feet between my deck and the workshop to the existing circuit that is terminated at my deck.

I will install an earth ground rod at the workshop.

Saturday Cowboy · 12-28-2010, 06:23 PM

what is your skill level? Is the existing circuit 4wire? romex? how are you going to splice this?

on a side note most backyard locations would require direct bury cable to be 24in deep

armyguy · 12-28-2010, 09:31 PM

I'm not an electrician but I have 40 years experience as an electronics tecnician working with radar systems and on several occasions I have run power to my systems typically from genertors, but thats it for my skill level.

The existing circuit is 4 wire UF-B cable in conduit, and since it was for a hot tub its a GFI circuit.

I will use an additional 50A disconnect box for my splice since already have one on hand and the additional 80' of cable will be buried at 24" in schedule 80 conduit IAW local code the same as my existing circuit.

Thanks for the help and I will have an electrician check it out before I have it inspected

JPraski · 12-28-2010, 10:11 PM

Sounds like it'll work. A couple of points:

You don't need to put underground cable in pipe, but you are allowed. (It does need to usually be in pipe down to the 24" depth, though.) If you use pipe, and have it all enclosed from box to box, just use loose wire, it's cheaper. You can even use the same color as long as you mark it properly (white electric tape for the neutral at both ends, for instance.)

The 24" is to the top of the pipe / cable, so make sure it's a 26" or so trench.

Saturday Cowboy · 12-29-2010, 08:44 AM

also your disconnect must be on the outbuilding. remember to keep your ground separate in subpanel.

SD515 · 12-29-2010, 10:04 AM

Quote:

Originally Posted by JPraski

...If you use pipe, and have it all enclosed from box to box, just use loose wire, it's cheaper. You can even use the same color as long as you mark it properly (white electric tape for the neutral at both ends, for instance.)...

Not if it's 6 gauge. Wire in pipe has to be 4 ga or larger before you can re-mark it, per NEC.

JPraski · 12-29-2010, 10:59 AM

D'oh! Thanks for that catch. Now I gotta go find that rule...

SD515 · 12-29-2010, 12:46 PM

Grounded conductor 200.6 Equipment grounding conductor 250.119. See also 310.12 (which refers to those two sections)

armyguy · 12-30-2010, 04:34 PM

Thanks to all