Electrical service to back shop question

[outsider347]

Looking for suggestion as to the correct (feed)wire size to power by back shop.

I have 200 amp service to my house,and I would like to have 100 amp service to the shop
The shop is 375 ft from the house, and the line would be buried, per the local code.
The shop is for hobby use,and I will be the only one using the single phase equipment.
220v compressor, 220v powder coat (kitchen) oven,120v mig,lathe,mill,and the usual array of power tools



Questions

1. does it have to be copper, or can I use aluminum?
any problem with using aluminum?
2. wire size?
3. Suggestion where to buy the wire

Tks Gents

 

[Charles (in GA)]

I'll let someone else do the calculations but that is a long run, and will need upsized wire. You will probably end up doing splices at the house to drop it to a smaller size for ease of connection to the breaker in the house panel.

There was a thread recently along these same lines, long run, upsized wire, splicing down to workable size at the ends.

Charles

 

[justsam]

I'll let the real experts weigh in on proper wire size, since I am not a pro.

My comment would be are you sure you need 100 Amp service? I know the story of do it now while the trench is open but a 375 ft run of any heavy gauge is going to be costly, and for a one man shop, I would consider going to something like 60Amp. With the loads mentioned you would have to have them all going full tilt at once to really need greater than 60 Amps.

Once the experts weigh in on proper sizing, you can make the determination on the cost differential, but I would expect it to be significant.

 

[outsider347]

I'll let the real experts weigh in on proper wire size, since I am not a pro.

My comment would be are you sure you need 100 Amp service? I know the story of do it now while the trench is open but a 375 ft run of any heavy gauge is going to be costly, and for a one man shop, I would consider going to something like 60Amp. With the loads mentioned you would have to have them all going full tilt at once to really need greater than 60 Amps.

Once the experts weigh in on proper sizing, you can make the determination on the cost differential, but I would expect it to be significant.

justsam:
you are correct with the "while the trench is open" thinking

If not too much trouble, maybe the pros could run both scenario for me

 

[Jester1]

You can run 100 a to the new shop, as far as al/cu wire you will have to look at local codes as some places have caustic soils as is the case in San Diego. If that is not a problem then triplex URD and a use ground will be fine. I belive (off the top of my head) you could go 1 up in cable size but I would size you up 2 wire sizes due to I have no idea what you do in your shop. Size for 100 al would be #2-2-4 but I would push you to 1/0 triplex and a #4 use ground and of course all correct grounding/ground rods at the new shop.

 

[outsider347]

Jester1
Thanks for your time here

What would be your suggestion for a 60 A service to the back shop?

Regards

 

[Jester1]

#2 would be fine. Some times you do not have a choice in wire size as parts houses/home centers will only carry the standards, sometimes ordering wire not on the shelf is not cost effective or timely. I don't have my book in front of me but I believe you could run a 70/80 a 2 pole breaker on that line. #6 would be with in 150' +/- for voltage drop #4 would be the up size But with your distance I would look to 2 sizes up being #2 al so you have no power issues or dimming lights.

Around here #4, #3,#1 are odd balls for feeders so we use #2 (100a), 1/0(125a) and 3/0 4/0 (200a) for feeders. All these sizes are readily available in both al/cu Most markets (pacific northwest and California) I have been in that is standard parts house fare.

Just remember that aluminum is always one size up to copper wire for feeders. I would point you to the AL for cost.

 

[outsider347]

Jester1

will this work?

http://www.ebay.com/itm/450-Stephen...-XLP-USE-/150900773969?_trksid=p2054897.l5677

 

[Jester1]

Yes for feeders and neutral, you still need a USE ground wire

 

[outsider347]

what size for the ground?

Would the ground wire attach to the ground rod?
or does it need to run the 375ft back to the panel in the house

Thanks for taking my rookie questions
ed

 

[pattenp]

You need to use a 4 conductor feed to your shop such as Mobile Home Feeder(MHF) or Quadruplex URD. Beware that URD cannot be installed inside of the structure. MHF can be installed inside, but needs to be in conduit. Also the wire size #2 in aluminum is only good up to 90A and at 375' is not going to be large enough to prevent excessive voltage drop. For 100A at 375' you need to use at least 4/0-4/0-4/0-2/0 aluminum MHF or URD.

Edit: URD is USE-2 rated insulation only and is not fire resistant. so that's why it can not be installed inside the structure. MHF is RHH/RHW-2/USE-2 and THHN/THWN-2 is approved for interior installations. URD is to be terminated outside the structure and will require a transition to something like SER to continue into the structure.

 

[Jester1]

This you don't need to up size it but i like to so #4

It will run with the feeders all the way to new panel and terminate on the ground buss (not the neutral). A secondary wire #6 bare solid copper will then go out to 2 ground rods spaced 6' apart min at the building no more than 20'. This is more or less for lightning.

Check your local codes or call a local electrician and "pick" his brain.

 

[Jester1]

You need to use a 4 conductor feed to your shop such as Mobile Home Feeder(MHF) or Quadruplex URD. Beware that URD cannot be installed inside of the structure. MHF can be installed inside, but needs to be in conduit. Also the wire size #2 in aluminum is only good up to 90A and at 375' is not going to be large enough to prevent excessive voltage drop. For 100A at 375' you need to use at least 4/0-4/0-4/0-2/0 aluminum MHF or URD.

Edit: URD is USE-2 rated insulation only and is not fire resistant. so that's why it can not be installed inside the structure. MHF is RHH/RHW-2/USE-2 and THHN/THWN-2 is approved for interior installations. URD is to be terminated outside the structure and will require a transition to something like SER to continue into the structure.

He is talking of doing 60 amps now. And quad is almost impossible to get here but yes I would go with quad and then you ground wire is in place. For what ever reason it doesn't make it past North Dakota for us. No idea why???

 

[outsider347]

Thanks for your responses!!
GREAT help to me

Best Regards
ed

 

[pattenp]

This is what promted my post.

You can run 100 a to the new shop, as far as al/cu wire you will have to look at local codes as some places have caustic soils as is the case in San Diego. If that is not a problem then triplex URD and a use ground will be fine. I belive (off the top of my head) you could go 1 up in cable size but I would size you up 2 wire sizes due to I have no idea what you do in your shop. Size for 100 al would be #2-2-4 but I would push you to 1/0 triplex and a #4 use ground and of course all correct grounding/ground rods at the new shop.

 

[Jester1]

Sorry it was suppose to be 100 a. The l snuck in there under my fat hamhocks and sloppy typing.

Later I said up one size for AL, that was CU.

 

[Ray-CA]

You can run your ideas through this (http://www.calculator.net/voltage-drop-calculator.html) to get some information.

Ray