I would like to run an underground wire from my driveshed to my garage to run a 4800 watt construction heater. I think they draw 20-25 amps. I don't have 220 in the garage. The distance is 200 ft. Is 10/2 UF wire heavy enough for that distance?

  • thanks for the replies , just to clarify I already have 110 in the garage , lights and receptacles . New line is just for heater – Ron Dec 7 '15 at 23:30
  • What's the make and model of the heater? Is it hardwired, or cord connected? – Tester101 Dec 8 '15 at 1:30

4800w @ 220V 21.81A. 10AWG is two small. 8 awg is right on the edge using 3% max voltage drop (uglys page 50) if you want to run any lights you should be using 6AWG for that long of a run.

| improve this answer | |
  • 2
    Ed has this right. Although, your residential voltage should be ~240 volts, still, his calculation for #8 wire is correct. Here is a handy calculator for voltage drop. southwire.com/support/voltage-drop-calculator.htm entering your parameters and a 3% drop yields #8 wire. – ArchonOSX Dec 7 '15 at 23:34
  • What size breaker should be used? – Tester101 Dec 7 '15 at 23:48
  • @Tester101 - wouldn't that depend on what the heater nameplate or instruction manual specifies (if hardwired), or the receptacle type if it's plug in? If it's a NEMA 6-30, that would imply a 30A breaker. – Johnny Dec 8 '15 at 0:14
  • I like the calculator link ArchonOSX provided. way faster than looking up and calculating... :) – Ed Beal Dec 8 '15 at 0:25

no. that is not heavy enough wire for what you want to do.

| improve this answer | |
  • What would the correct size be? – Tester101 Dec 7 '15 at 23:43
  • 30A would be the next larger size since it draws +21A – Ed Beal Dec 8 '15 at 0:20

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.