I am 350 feet away from my breaker panel in the house to a shop I am planning on using. I need a 30amp 240 volt service for my wood working saws and lights. What size wire do I need to handle the voltage drop. Thanks Jim
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I am 350 feet away from my breaker panel in the house to a shop I am planning on using. I need a 30amp 240 volt service for my wood working saws and lights. What size wire do I need to handle the voltage drop. Thanks Jim
Normally a 30 amp load requires 10 awg wire, not sure at that distance though, you may want to go up to 8 awg wire to reduce voltage drop. Someone else will provide input.
I assume you are going to run this to a subpanel in the shop. If this is the case, why not use 6 awg wire and make it a 50 or 60 amp subpanel? This would leave room for expansion in the future.
For every 50' of run you need to up to the next heavier wire. I'd just go with #1and be done with it.
Sorry ballen, this is just not true. It may have been an old wives tale back in the day, but we do things a little more accurately now.Quote:
For every 50' of run you need to up to the next heavier wire.
You need to do a calculation to be sure.
With a load of 30A @ 240V I get #4cu
With a load of 20A @ 120V I get #3cu.
Both of these are realistic numbers for this installation.
Ironically, the more things running the lower the voltage drop, assuming the load is pretty well balanced. Voltage drop @ 240V is dramatically less than @ 120V.
Personally, I'd go with #4 and a 50A breaker. This is more than safe and reliable for such a feeder.
Why copper? You will have a heart attack when you pay for that much copper and that distance. What would the local utility charge for a pole and drop?
Stan thanks for the info but can you show me how to do this calculation and why a 50 amp when the op says he only needs a 30? Xcbuilder, are you running 240 or 120, I'd do 240 for some shop equipment but I don't know exactly what you have planned.
I don't do the math, I use an online calculator. In the field I have several apps on my phone and iPad.Quote:
Stan thanks for the info but can you show me how to do this calculation and why a 50 amp when the op says he only needs a 30? Xcbuilder, are you running 240 or 120, I'd do 240 for some shop equipment but I don't know exactly what you have planned.
I would go with a 50A feeder because even though he says he only needs 30A that is a long way to run if he needs more someday. IMO anything less than a 50A sub-feeder is silly.
Also, I like to sometimes check what the drop will be at different amperages and at both 120v and 240v.
Bal the most accurate formula recommend by IEEE is :
Vd= 2*I*L*R/ft
Which is what the on line calculators use. So much easier to use the on line calculators.
While the poster requests copper wire, I would suggest #2 aluminum in a 4 wire URD direct burial cable. If soil conditions are rocky I would sleeve in 3 Inch PVC conduit for extra protection.
Don't we need to know if he is going 120 or 240? The calculator I tried to use requires the voltage
Xcbbuilder states:
Quote:
I need a 30amp 240 volt service
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