Choosing wire size to run to a sub panel
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Choosing wire size to run to a sub panel
Hi yall, I'm going to be running g a 100amp sub panel in my pole barn. Its going to be coming off of my 200 amp panel In my house the total run from Main panel to sub panel is about 220 feet. I ran 2" conduit last weekend. I would like to run alum wire, now my question is what size wire would be big enough for my sub panel, I know its something like a 10% drop for every 100 feet of the run. Also is it 3 wire or 4 wire. thank you
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You need 4 wire. I suggest using #2/0 Mobile Home Feeder at that distance for a full 100A. Such as this... https://www.wireandcableyourway.com/...der-cable.html
Oh but the problem is going to be 2" conduit may be too small. You need 2.5". Using aluminum you need to drop down to #1/0 using AL THHN/THWN or XHHW. https://www.wireandcableyourway.com/XHHW-2/
Edit: After looking at the MHF 2/0-2/0-1-4 it may be okay in 2" conduit because of being compacted conductors, but it will still be a bear to pull.
Oh but the problem is going to be 2" conduit may be too small. You need 2.5". Using aluminum you need to drop down to #1/0 using AL THHN/THWN or XHHW. https://www.wireandcableyourway.com/XHHW-2/
Edit: After looking at the MHF 2/0-2/0-1-4 it may be okay in 2" conduit because of being compacted conductors, but it will still be a bear to pull.
Last edited by pattenp; 08-28-16 at 04:16 PM.
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When I got the conduit they said 2inch would be fine for what I would be doing I hope I didn't get screwed, but I need 100amp service because I have welders and stuff that are going to be ran out there
#5
Why do you need 100 amps?
Outbuiilding master breaker and supra panel breaker would still be selected using continuous loads where applicable.
(Branch circuits in the outbuilding still need appropriate continuous/intermittent calculations unless they, too, were upsized for voltage drop in a very large building.)
#6
1/0 aluminum will give you a 3.82% voltage drop at 100 amps, and 240 volts.
Voltage drop will depend on load. The lower the load, the lower the voltage drop.
I suggest adding up what you think you will have for equipment in the pole shed (saw, welder, heater, etc.) and then figure your your wire size. Remember only figure what equipment will be running all at one time.
For example, if your load was only 50 amps you could use #4 aluminum. That would be quite a savings over 2/0 aluminum.
Voltage drop will depend on load. The lower the load, the lower the voltage drop.
I suggest adding up what you think you will have for equipment in the pole shed (saw, welder, heater, etc.) and then figure your your wire size. Remember only figure what equipment will be running all at one time.
For example, if your load was only 50 amps you could use #4 aluminum. That would be quite a savings over 2/0 aluminum.
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When I got the conduit they said 2inch would be fine for what I would be doing I hope I didn't get screwed,
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For example, if your load was only 50 amps you could use #4 aluminum. That would be quite a savings over 2/0 aluminum.