A/C motor needs help getting started

Discussion in 'Miscellaneous Repairs & Maintenance' started by FARfetched, Oct 1, 2019.

  1. FARfetched

    FARfetched Active Member

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    2001 Starflyer with Carrier Air V A/C.

    Last weekend, when I went to fire up the A/C, it started humming along and then the breaker tripped after a couple minutes. Fortunately, we didn't need it then.

    Today, I set out to figure out what was happening. I took the panel off and cleaned up 18 years of grime and mildew, then reached up and gave the squirrel cage a spin. It turned smoothly and easily. Playing a hunch, I reset the breaker, gave it another spin, then turned it to "Fan Low." It spun up and started blowing air—that's a start, anyway! I turned it off, put the panel back on, and tried again. Hummmmmmm and no air.

    Anyone have any experience with this vintage of A/C? I'm guessing a capacitor in the motor is shot. Is this something I need to punt to an HVAC person, or do I have a reasonable chance at a DIY fix? (I can solder, if that's an issue.)
     
  2. xxxapache

    xxxapache Well-Known Member

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    Start up capacitors are easy to replace
     
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  3. Sjm9911

    Sjm9911 Well-Known Member

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    I always go oil and cleaning first. Its 18 years old and doesn't get used much. If that dosent work you can go on to replacing stuff.
     
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  4. FARfetched

    FARfetched Active Member

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    Yeah, I'm always telling DW that Troubleshooting 101 is "check the easy stuff first." I guess I should follow my own advice. :D

    Now… has anyone ever pulled a motor out of one of these? Is it better to go in from the bottom or top?
     
  5. bols2Dawall

    bols2Dawall S.W. Ontario

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    Are you plugging into minimum 20 AMP ?
     
  6. FARfetched

    FARfetched Active Member

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    Symptoms were first seen at the campsite, 30A service. My plug in the garage is 20A. I'm using fan mode at home, not A/C mode, so I'm not getting the compressor involved just yet.
     
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  7. FARfetched

    FARfetched Active Member

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    UPDATE: I took the cover off (15 Phillips screws), and the motor is out in the open! The question is, has anyone ever taken one of these out?

    IMG_2464.JPG

    It sure was helpful of them to put the capacitor value on the label (12.0 µF / 370 V). I presume those are two clips holding the motor down. Removing the fan looks simple enough, but what about the other side?

    Or… am I making a bad assumption that the capacitor is inside the motor? If it's external, where would I find it?

    Everything is turning smooth as butter
     
  8. FARfetched

    FARfetched Active Member

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    Oh cool (see what I did there?), I just found a service manual. I now know what I need to do and how to do it.
     
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  9. FARfetched

    FARfetched Active Member

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    Update: Given a pleasant afternoon, I pulled the capacitor. It's rounded on both ends, so it's safe to say it's shot (and likely the root cause).

    That's the good news.

    The bad news is, I'm having a devil of a time finding a drop-in replacement. I've had a crash course in A/C capacitors this afternoon. Many units have what's called a "dual run" capacitor—one for the fan motor, one for the compressor—and my 2001-vintage AirV is one of those. They're pretty common, but it seems Carrier chose an oddball that nobody, uh, carries anymore. This one is 12/40µF, 370V. The closest I've found is 40/10µF and (from Dometic) 40/15µF, and I'm not sure either one would fit in the enclosure. I might be able to go with separate 12.5 and 40µF capacitors, depending on their widths.

    For reference, here's the info off the side of the capacitor.

    It's roughly 4" long (minus the contact cluster, which adds another 1/2 inch) and 2" diameter.

    If someone has better Google-Fu than me, and can point me to a good replacement, I'd much appreciate it. I walked through 20+ pages of eBay listings without any luck, and Amazon isn't any better.
     

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