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I have a shed, that has a sub-panel, with a main breaker at 30 amps (Green). On each side of the 30amp breaker is a 15amp breaker (Black).

Form what I can tell, one of the 15am breakers goes to one outlet which is dedicated to powering my pool pump.

The other 15amp breaker, goes to lights, and other outlets around the yard.

Currently my pool pump is running on this 15amp 120V outlet, but I've read, that these pumps are more efficient on 240v.

In my house, I have heaters that are wired to 240v (20amps), but I've never seen 240v on 15 amps. Is this something that I could do?

I don't think I can just replace the 15amp breaker, with a 20 amp breaker correct? Since the main sub-panel breaker is 30, so 20 + 15 would be 35.

Do I have any options to make this work? I don't know if 10amp breakers exist to switch to 20 / 10 maybe?

Any help would be appreciated!

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    What is the voltage written on the pump? I suggest you get an electrician to do this properly for you.
    – Solar Mike
    Jun 7 '21 at 12:22
  • Lots of possibilities. But need to start with a picture of the subpanel. Jun 7 '21 at 12:30
  • @SolarMike pump says VOLTES 115/230, it has a little switch based on what voltage you are sending to the pump. Currently it's set to 115
    – Amir
    Jun 7 '21 at 12:32
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    Are there any more breaker slots available in the subpanel? (As manassehkatz indicates, a picture would answer this.) Jun 7 '21 at 12:40
  • Off hand, you need a new breaker, new cable, and maybe a new sub panel. Breakers can add up to more amps than the main breaker, you just can't use more than the main breaker at a time.
    – crip659
    Jun 7 '21 at 12:40
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Generically, since so far there are no pictures or specs to refer to:

Yes, 15 (or even 10) amp two-pole 240V breakers are available. They are somewhat uncommon, but my mini-splits happen to call for a 15A 240V breaker. No special-ordering was needed to find one, they were on the shelf.

More efficient on 240V is not exactly false, but is also a rather small effect for a 120V / 240V motor. So I doubt that spending money and effort to change this will noticeably affect your power bill. Assuming the wiring to the motor is properly sized now, there is a small but real reduction in resistive losses in the wiring, and almost no change in the power consumption at the motor itself (again, some resistive losses inside the motor are reduced, but the motor doing work is going to cost the same amount of power to do the work.)

IF (we don't know, since no pictures) your current subpanel feed is 30A at 240V, two 15A @ 120V circuits are only loading it by half - you could have 4 15A@120V circuits fully loaded (60A at 120V) without overloading a 30A at 240V feed. Using a 20A @ 240V breaker for your pool pump would not overload it, but probably is far more than you need if your pool pump operates on 15A @120V now - it should be roughly 7.5A at 240V, and likely the wire is sized for the 15A breaker, so a 15A or 10A at 240V breaker would be more appropriate, and not require replacing the wire to the pump.

We also don't know if your sub-panel has spaces to accept more breakers, (since a 240V breaker takes up twice the space that a 120V one does) or if it's properly wired at present. If it is, it can be done; But I doubt you'll see enough savings to pay for it.

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  • Wow, thank you for this fantastic answer! I've learned something new and basically I will leave things as they are! "you could have 4 15A@120V circuits fully loaded (60A at 120V) without overloading a 30A at 240V feed." This line here really eye opening! I don't know why I didn't think of this before! To answer your question, the sub panel is small and full, I could replace it, I've done this before, but like I said, since you say the cost won't be worth it, I'm not going to touch it! It all runs fine! Again thank you for answering my question!
    – Amir
    Jun 7 '21 at 14:02

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