OK, I have a "shop" that I have built next to my house and would like to power it. I have a 200A service panel outside my house feeding a 100A panel in my garage that feeds the entire house. There is about a 75-85 ft run from the service panel to the shop where the location of the panel will be in the shop.

I have the following I will be using in the shop:

240V air compressor (3.5hp rated @ 15A)
120V welder (rated @ 20A)
240V plasma cutter (rated @ 25A)
standard house stove 220V only using the oven for powder and ceramic coating small parts (will only be used for 1-2 hours at a time, with a good chance of the compressor cycling while in use)
standard refrigerator 120V (maybe)
6 Metal Halide lights converted to 120V like these Industrial High Bay Metal Halide Light 400 Watt 120 V - No Lens Cover | eBay (probably only going to put 2 per circuit as I think 6 are overkill for this shop but they came with it so I didn't argue.)
and then will have outlets for the use of other various tools, battery chargers, radio etc.

I will probably never be using ALL the above at the same time, though the lights (at least 2 will be on whenever I am in there) and compressor will be on at the same time and when the plasma cutter will be used it will require the compressor to cycle on and off also.

The run from the service panel will be ran under my house (approx 65ft) and then through conduit to the shop (approx 15ft).

I *think* that 6/2 will "work" grabbing the 2 hot and neutral lines from the service panel and then install a 8-10ft ground rod and ground wire at the shop for the panel.

Will this size wire be OK or do I need to look at a larger gauge wire due to the length of the run and the possibility of exceeding the 55A rated amperage of the wire? Would I need 3 conductor + ground to bring the ground from the service panel also?

I have done electrical before, just nothing quite this big.

Any and all advice is appreciated.

 

you will need two hots (red and black) a neutral (white) and a ground (green) from the panel on the house to the shop... wire size should be 2/0 not 6... this will give you the full 100 amps that the new panel you will need to install on the shop. You will also need to put two 8 foot ground rods (6 feet apart) in the ground and run separate wires up to the panel.

You can get a double pole 100 amp circuit breaker for the house and put the two hots on it and then run it to the new shops panel.

Even though you counted up only 55 amps of stuff... you have to go with the compacity of the panel you are installing... and the lowest you will want to get is the 100 amp one.

If you have any other questions pm me...

 

That's what I was afraid I would have to do. unfortunately it looks like i will have more money in the wire than i will in the building....

now if i can find a spool of wire as it falls off the back of an electrical truck.....

 

If does not need to be inspected i would use # 4 rated at 85 amps and just ground sub panel at garage.so 2 hots and neutral. electritions have to over wire for code.but make shure you over size conduit for heat disapation. just dont fall for the aluminum wire!

 

ya no inspection will be needed unless someone rats me out.

IF i can get some #4 i'll do it, there isn't much selection of wire around these parts.... I'd love to do it with huge wire but don't want to sink $1000+ in wire......

 

it is standard to over rate power usage now because of regulations! and wire is easy to come by if you want to pay for.

 

i don't want to pay for it........

 

go to home depot and get the number 2 wire... it has the red, black, white and green in it and is $3 a foot... not that much... its worth having it done right to prevent a fire isn't it?
Im sure you don't skim out when it comes to your truck do you?

 

That was 2/0 not #2 right?

 

2/0 is for aluminum wire size, for 100 amp ou can use #2 wire or if you really want to avoid the voltage drop jusat use #1 copper- 3 leggs-2hot one neutral and you can use #6 for ground. you will need 2 8' ground rods with a piece of bare solid #6 connecting both rods/spaced at least 6' apart but not more than 10' apart/ and that wire will go to a groundbar kit in the panel. you will use the green ground screw that comes with panel to bond the neutral bar to the can.I would look into using alum. ser cable, let me look into it and I will get back to you