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AssuredElectrical
AssuredElectrical, Master Electrician
Category: Electrical
Satisfied Customers: 4241
Experience:  Contractor-42+ Years in the ElectricalTrade
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I plan to install a 30 amp, 240V circuit to a remote location

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I plan to install a 30 amp, 240V circuit to a remote location on my farm. I have a metal building with 200 amp panel board, already installed. The new 30 amp panel will be outdoors, about 850 ft. away. I calculated that direct burial 2/0-2/0-1 URD cable will result in only 3% voltage drop. So, can I install a 30A, 240V breaker into the existing 200A panel, and wire directly to it with the URD cable? Do I need to run 4-wire circuit (2 load, 1 neutral, 1 gnd)? Should the ground wire be 1 Ga. also? Does the 30A Outdoor panel need grounding rods?

AssuredElectrical :

Welcome. My name is XXXXX XXXXX would be glad to assist.

AssuredElectrical :

The calculation is very good on the distance and wire size. I show approx 2.9% drop

AssuredElectrical :

Will you only be using 30 amps 240 volts at the location? Or will yu have 120 volts needed?

AssuredElectrical :

If you will use 120 and 240 at the 30 amp panel, you will need the 4 wire feeder.

AssuredElectrical :

If only using 240 volts and no 120 volts, you can use the 3 wire feed

Customer:

I will have 1 circuit that is 15A, 240V to power a 3/4HP pump

AssuredElectrical :

Ok, then just a 3 wire feeder is good then. You still do need a ground rod at the location to tie into the ground at the panel as well.

Customer:

I will also have one or two lighting circuits, 15A, 120V, and one or two receptacles, 20A 120V

AssuredElectrical :

Ok, then you need 4 wire feeder

AssuredElectrical :

Neutral needs to be 2/0 as well, it will carry the return current, prefer to be on the safe side at that distance.

AssuredElectrical :

Especially with all the 120 volt items possibly operating

AssuredElectrical :

Ground on 30-60 amp circuit Table 250.122 is required to be #10 copper or #8 aluminum

Customer:

OK, so I've already ordered the 2/0-2/0-1 cable, so I can use the 1Ga for the ground, and now I have to buy a 2/0 single for the neutral?

AssuredElectrical :

You can use the #1 as the ground if you wish, overkill , but you already have it

Customer:

How can I connect the 2/0 conductor to the breaker? It only will fit a #2 Ga?

AssuredElectrical :

The #1 would actually carry the full unbalance of the system it appears for the neutral it is good for 20 amps

AssuredElectrical :

That is always the issue when running such a distance. Usually mount a disconnect outside and run the normal 30 amp from the panel to the disconnect and then the larger cable will fit in the disconnect lugs

Customer:

OK, so I was trying to avoid having to mount the outdoor disconnect on my metal building, but it makes sense to do it as you say. Now, what if I mount the disconnect on the outside wall, but it is 60 ft. away (on opposite side of building from the 200A panel) What size conductors would I need to connect between the panel and the disconnect? (I use EMT conduit inside the metal building)

AssuredElectrical :

Standard #10 should fair well. The drop will be at the disconnect to the panel.

AssuredElectrical :

If you have the resource, you could bump it up to #8 which is a step above. That would be you call

Customer:

OK, just one more question: the trench should be 24-30" deep? If it crosses under a driveway (gravel farm lane), does it need to be run thru conduit? What size?

AssuredElectrical :

ok

AssuredElectrical :

you can stay the standard 24" and no conduit is needed.

AssuredElectrical and 3 other Electrical Specialists are ready to help you

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