Our well pump motor was recently changed (it was making a huge racket, burning up switches one after the other etc. The bearings were going out). Smooth sound, no more burnt switches, water pressure is fine (the switch is a 40/60).

Before that, there were no problem with it tripping a breaker, it was in a bad shape, but it worked (even if, as previously mentioned, it was burning through switches.)

Now, we noticed it tripping a breaker in the evening only (so far), sometimes multiple times in a row, sometimes not. We live in an old house, but have a brand new breaker box. The pump supplies this house and a small trailer where a couple of tenants live.

As far as electrical circuit configuration goes, we do not know whether or not the pump lives on its own breaker (a 20A single pole as far as I can tell) or shares it with something else. So far it doesn't seem like there is anything else on that breaker.

I'm thinking of sanding the hot wires going to the pump to get rid of the carbon deposit (they look pretty bad from that last burnt up switch) and getting a 30A single pole breaker to replace the 20A one. Is this a good idea? Any input is very appreciated.


EDIT 2: Possible solution?

According to my research, here's what should happen :

  • Get some 12 gauge wire
  • Get a 240V, 20A breaker
  • Hook up the pump and only the pump to that breaker

Anybody care to comment? Also, why is it apparently a no-no to wire a jet pump to 115?

EDIT: Motor specs

Old motor:

  • Volts: 115/230
  • Amps: 13.0/6.5
  • Max Load: 16.2/8.1

New motor:

  • Volts: 115/230
  • Amps: 12.4/6.2
  • Max Load: 16.2/8.1
  • 1
    It's not strictly forbidden or anything, it's just bad practice to wire a heavy-duty motor that can run on 220 for 110. Among other things, more power is wasted heating the wires (double the current, 4 times the resistive losses.) Certainly looks like the specs on the new and old motors match up pretty well.
    – Ecnerwal
    Commented Dec 5, 2014 at 23:10

1 Answer 1


Was the motor replaced with the same size (horsepower, amperage, voltage) motor? What is the amperage and voltage listed on the motor's data plate? In many cases the motor plate will either list the size of the required breaker, or if not, the manufacturers website will have that information available. If you "had the motor changed" it might be best to call the company that changed it and report that the new motor is tripping the breaker, where the old one did not, and have them check for issues, since they should have verified that the new motor would work the same, or made any changes needed to support any change in the motor. If you changed it yourself, that's on you.

You should not replace the breaker with a larger breaker unless the new motor requires a larger breaker.

You should not replace the breaker with a larger breaker without ALSO replacing the wire with larger wire, suited to the size of the larger breaker, which should be suited to the size of the new motor. 20 amp, 12 gauge copper, minimum - 30 amp, 10 gauge copper, minimum.

Rather than "sanding the wires" you should (with the breaker off, of course) cut off the damaged ends of the wire, pull it a little further in, and strip the ends to get new undamaged wire. If this is not possible, consider replacing the wire, especially if it's fairly short run.

110V (single-pole breaker?) is rather abnormal for most well pump installations. One potential fix would be to re-wire for 220V operation if possible

  • Thank you @Ecnerwal for taking the time to respond, I appreciate it as I am fairly new at this. By single pole, I meant that the breaker has only one "handle". How would one rewire for 220V operation? I know I can turn a knob in the motor to operate at 220V, but wouldn't I have to change wires too? Thanks. PS: I've edited my answer to show motors specs.
    – Krimo
    Commented Dec 5, 2014 at 15:38
  • 1
    Some 220V two-pole breakers do have a single handle. But they always take up two spaces in the breaker box, and have two "hot" terminals coming off them (inside the breaker box - if you are not comfortable taking the breaker box cover off to have a look, don't - you can see the width of the breaker from the front of the box with the cover on.) If you are changing from 115 to 230V operation the wire does not need to be changed (virtually all household wiring is 600VAC rated.)
    – Ecnerwal
    Commented Dec 5, 2014 at 23:14
  • Ah yes, that's the information I needed! What I'll do is get a 2-pole 20A breaker and hook up the pump to it, and report back. Thanks for all the help!
    – Krimo
    Commented Dec 6, 2014 at 0:25

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