My HVAC guy tells me that the capacitor on my Carrier 38tkb024 AC unit is weak and will need to be changed soon. They want to do it for only $405. I found out a capacitor costs only about $20! What a rip off. So I'd like to get someone else to replace the capacitor for me. But it's so hard to figure out which one I need. I tried one online parts store, and they said I needed one that is 440v, but that doesn't seem right to me, as the unit says only 208 to 230 volt on the back. Can anyone help?

Thanks

The cap on your unit will have the ratings right on it. It may be under the mount or on the back side, so you may have to remove it to see. It will be something like 5+35uf/mfd 370/or 440v. 370 or 440 will work just fine, but you need to be exact with the uf or mfd rating. Now, $405 to change a capacitor?! Outrageous. Are you sure they weren't talking about a complete compressor change out?

I agree completely with mygirlsdad777.

The 370 and 440 VAC is the (BACK EMF) rating on the capacitor. If you have a capacitor with 370 VAC rating you could use a capacitor rated for 440 VAC but not vise-versa. 440 VAC capacitor has more insulation between the grids of capacitor than does 370 VAC.

A 35/5/440 capacitor will work just fine. It will replace the part# P291-3553RS used on your system.