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I am replacing a 120 volt septic pump rated at 13.8 amps with a 240 volt 6.5 amp pump. The pump is located 150 feet from the electrical panel. I am putting in a 15 amp double pole breaker and would like to use the 14 AWG wire so that I don't have to rerun the line. Is it OK to do this?

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Yes, that sounds fine.

You will be much better off at 240V - voltage drop would be pretty bad for 14A@120V, and #14 wire was wrong for that. However 6A@240V will be 4 times better, because voltage is doubled and current is halved. 6A is fine on #14.

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  • Thank you so much! I'm not sure how it even passed. It was put in by the previous owner of the house when we bought it as part of the sale. The pump has failed 3 times in 9 years. The wire gets so hot you can't even touch it.
    – Zach
    Jan 7 at 22:18
  • If it's been heating up that much, you might want to inspect as much of the wire as you practically can even if you aren't replacing it, just to make sure the insulation is undamaged...
    – Grant
    Jan 7 at 22:26
  • @Grant Even low temp UF is rated for 60C, which you wouldn't want to touch. Most other wires are 90C rated. 15A is the short time (<3 hr) limit for #14 at 60C. The problem is startup surge, probably already has 5% voltage drop, at 6 times starting surge that is like 30% drop. No wonder motors fry! Well now it will be like 1% continuous, maybe 6% starting drop which is fine. Jan 7 at 22:30
  • Part of the issue is to the contractor who installed it just connected the pump onto a circuit that has 6 receptacles. It wasnt even run on its own circuit so I'm just going to rerun the whole run with 14 guage. I was just not looking forward to pulling cable through 60 foot of buried conduit in single digit temperatures.
    – Zach
    Jan 7 at 22:38
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    If the conduit is the whole way or if you can put J-boxes at each end, maybe do the conduit run in THHN stranded wire. MUCH easier to pull! Note NM cable is not ok outdoors, not even in conduit. Jan 7 at 22:56

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