I have an HVAC system that has a condenser fan motor that has gone bad. The motor is no longer available. What considerations do I need to make in order to replace the motor with a different motor?

For example, if the voltage is the same, can I replace the motor with one that has similar speed? Would it just require a matching capacitor?

Additionally, can it be switched over to brushless?

  • Posting the brand/model of the piece of equipment that's failed will get you a better answer.
    – FreeMan
    May 26, 2020 at 12:56
  • Thank you. I see a number of questions on this site for specific motors. I was hoping to get a feel for the approach that the experts take. From a circuits standpoint, it appears that the electrical interface allows for swapping as long as some basics are heeded. There's also the downstream considerations such as fan speed for moving enough heat. Looking for understanding of those things that matter. May 26, 2020 at 16:35

1 Answer 1


You will need to match the RPM and the HP rating will need to match or exceed the original motor. Don't mess with "close enough" RPMs. Higher, and you will increase HP of motor needed by some unknown amount and potentially burn out motor. Or you will push the fan blade to RPMs it wasn't designed for and it could fail catastrophically. You will need a capacitor appropriate for the motor. You can use a brushless motor.

  • Thank you. That makes sense. Do you have any technical sources you can reference? How do I know what capacitor to use? Also, I've seen mention that brushes doesn't need a capacitor, but need more info. Jun 7, 2020 at 15:40
  • LMGTFY... here is an exhaustive reference for motor replacement thedealertoolbox.com/custom/assets/Files/…
    – user278411
    Jun 11, 2020 at 12:01
  • It sounds like you're being snarky with the LMGTFY. I did google it and found a bunch of unhelpful noise, so I came here for help. That said, the link that you reference is fantastic. What keywords did you search on? Jun 11, 2020 at 17:57

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