Question about Carrier Heat Pump Dual Start Capacitor

[sylvester35]

I've got a Carrier 10 SEER residential heat pump. Somehow I've managed to burn out the start cap for the compressor/fan 3 times now in about 7 years of owning the unit. This last one was some "Packard" brand I purchased from a local appliance parts store. Lasted about 10 months, and now it seems the HERM side is shorted

I want to make sure when I replace it this time that I install the right capacitor (or one better) to do the job. Since I didn't write down the original specs, I can't seem to find a model to exact spec for this unit. The last one I have here is rated at 50+5MFD and 440VAC 50/60HZ. This is a model 38ycc042 carrier and I've googled and googled for the information but can't find it. I notice a common size is 40MFD at 370VAC but I'm just not sure what is appropriate for this * Also, I don't want to spend a lot on another stupid capacitor only to have it blow again in less than a year. Thanks much for any help on this! It's getting pretty hot around here now

[paul292]

You can look it up on your compressor and fan nameplates if its designed for 370 you can't put 440vac, if its 50-5 it means its 50mfd for compressor and 5mfd for fan you can't put any smaller or bigger otherwise it will have bad effect on your components and will go bad prematurely. take the cover off your condenser and see what its designed for. good luck!

[nomadpeo]

actually, the voltage rating on a capacitor has more to do with temperature rating. it's a strange rating, but the two choices are 370 vac and 440 vac. the latter can withstand more heat.

the mfd rating can be verified with carrier. call a carrier distributor with the model number of the condensing unit and they can pull it up by their part number and tell you the mfd rating and sell you the capacitor for that unit. if they won't, try to verify the rating and buy it somewhere else. there may be inferior capacitors out there, but it's usually operating conditions that take them out.

the bigger issue could be that the compressor is getting weaker and may need help starting. if it does not have a hard start kit, it may be a good idea to add one. this will reduce stress on the run capacitor in question and possibly help to add more years to the compressor. it comes with a relay that drops the capacitor out of the loop after each startup. the run capacitor stays in the circuit througout the cycle. also, make sure your condenser coil and evaporator coil are clean and that the freon level is correct. these things can contribute to component failures as well.