Capacitor replacement

[DanSTL]

Originally Posted by Wavery

https://getrvparts.com/dometic-air-c...pacitor-45-10/

Thanks Wayne so 45/10 should work? Only problem is the one you linked from dometic has a 2.5 in diameter so it won’t fit in the existing just under 2 inch diameter sleeve.

I will keep looking but as I’d be using AC a lot I’d rather replace original vs hard start boost. I did find this which gets me close to 45/12 but it is also too wide. https://a.co/d/crQDvfa

[Wavery]

Originally Posted by DanSTL

Thanks Wayne so 45/10 should work? Only problem is the one you linked from dometic has a 2.5 in diameter so it won’t fit in the existing just under 2 inch diameter sleeve.

I will keep looking but as I’d be using AC a lot I’d rather replace original vs hard start boost. I did find this which gets me close to 45/12 but it is also too wide. https://a.co/d/crQDvfa

I had the same problem. If I hadn't already installed the hard start capacitor, I was thinking that a 45/5uf, 370V capacitor might work. From what I've read, the fan motor only requires 5uf. I'm not sure why they installed the higher rated ones in both of our units. Then again, my trailer is 24 years old and the capacitor may have been changed a number of times, yours too. I may contact Carrier Support and see what they say.

[Wavery]

Originally Posted by DanSTL

Thanks Wayne so 45/10 should work? Only problem is the one you linked from dometic has a 2.5 in diameter so it won’t fit in the existing just under 2 inch diameter sleeve.

I will keep looking but as I’d be using AC a lot I’d rather replace original vs hard start boost. I did find this which gets me close to 45/12 but it is also too wide. https://a.co/d/crQDvfa

I received this capacitor. It's as close as I could find.

[DanSTL]

Turns out my original capacitor is okay (was able to test capacitance)! Thinking it’s my compressor I tested that using a test I found online measuring resistance across three terminals (A=B+C) and it’s good too!

So I’m going to try to isolate and think it’s either my control box, heat overload, or thermostat but with Carrier ACs discontinued it may be a challenge finding replacements if I can isolate.

[DanSTL]

Originally Posted by Wavery

I received this capacitor. It's as close as I could find.

Even though my original capacitor is reading normal at 45uF and 12uF, after many online searches I found and ordered this one and will replace as the original has small burn marks and figured I can try out a new one. I went 60+12.5 as it's the only one with the right diameter that fits and I read it's better to go a little high vs. low (especially on run capacitance of 12uF).

https://www.amazon.com/60-12-5-Round.../dp/B07QMSQKPW

[DanSTL]

Condensor fan just needed a manual assist and up and running

[DanSTL]

Yes that’s what I meant. I do have a dual run capacitor on order and Wayne also thinks my capacitor is bad despite regular microfarad readings. Sounds like the manual assist corroborates that even though the capacitor is not swollen , it is likely root cause of failure and not the fan. I thought the condenser fan might be the issue as it is rusty but it spins without any resistance.

Interestingly I shut off the AC and my 2nd attempt to run it was successful without any manual assistance to the fan which is why I thought the capacitor was fine.

If the replacement capacitor doesn’t fit I plan to try the hard start addition suggested here .

[Wavery]

Originally Posted by DanSTL

If the replacement capacitor doesn’t fit I plan to try the hard start addition suggested here .

The "Hard Start" capacitor is normally used for the run capacitor for the compressor motor (the HRM side of the dual capacitor). I'm not sure what it will do if you hook it to the fan motor side of the dual capacitor. Maybe Bill can be of some help there.

[DanSTL]

Isn’t the condensor fan being run by the “run capacitor” vice the “start capacitor “? That was my understanding which means I probably won’t benefit from the hard start, but if it’s the start capacitor then maybe it could help.

[Wavery]

Originally Posted by DanSTL

Isn’t the condensor fan being run by the “run capacitor” vice the “start capacitor “? That was my understanding which means I probably won’t benefit from the hard start, but if it’s the start capacitor then maybe it could help.

The blue wires on the dual capacitor is for the fan. The red/white wires is for the compressor.