[dick_linn]

I have an unusual situation. I'm preparing to connect power to the premises for the first time. The Main disconnect and point of entry will be at the pole barn 40 ft from the power lines. The house, 200ft away from the barn and 240 ft from the pole, will be fed from the panel installed in the barn via 4 conductor 4ought Al already in place. Question is, do I need to install a full 30 breaker service panel at the barn where I don't need all those circuits?
And does the house panel then treated as a "subpanel" and wired accordingly?
Thanks for the help,
Dick

 

[AllanJ]

Whatever panel holds the main disconnect switch or breaker has to be rated for 200 amps or whatever your service is. They do make "plain" disconnect switch boxes where you can run a conduit to a smaller subpanel with top breaker down below and also run the cable to feed the power to the main house.

In your case, yes, your "main" panel in the house is a subpanel and must have grounds and neutrals separated.

4ought = OOOO

 

[J. V.]

I would use a 200 amp "feed through" panel in the barn. They come with just a few slots for breakers, but have lugs that you connect the wires that go to the house. Some people call them "trailer" panels.

200' is a long run. Have you considered letting the power company provide a new service to the house?

 

[dick_linn]

Thanks for the advice, I hadn't considered the "trailer" type service panel. That seems the best way, I'll just have 220 for the welder and a couple of light and utility circuits in the barn. I'm not really looking forward to doing any more than the minimum business with the power company. The whole idea is to be able to fire up the welder and provide backup for the solar/wind system I've been using for the last 20 years. I may or may not decide to go the interconnect route with the power company.
Thanks again,
Dick

 

[AllanJ]

Since you already have the cable in place between the house and the barn, there is much less incentive to have the power company put in a separate service for the house.

If you went with the trailer panel, you could add a subpanel for the barn off of the trailer panel if you outgrew it

 

[nap]

4ought = OOOO

4/0


at 200 feet to the house , you really need to consider voltage drop. I haven't done any calcs but I doubt 4/0 will give you an acceptable calc.

 

[AllanJ]

According to my calculations the 4/O aluminum will handle 240 volts @ 200 amps at 3% voltage drop.

The voltage drop may be greater, percentage wise, for 120 volt loads if all 200 amps are drawn on one side of the 120/240 volt service and significantly less on the other side. Maximum of 6% (the same 7 volt drop) for 200 amps drawn on one side and zero amps on the other side but this is probably impossible because some of the larger loads are 240 volt.