View Single Post
Old 04-06-13, 12:00 PM   #2
Supreme EcoRenovator
AC_Hacker's Avatar
Join Date: Mar 2009
Location: Portland, OR
Posts: 4,001
Thanks: 303
Thanked 712 Times in 532 Posts

Originally Posted by kfreeman View Post
I have an old Janitrol heat pump that keeps burning out the compressor start capacitor.

NOTE: If you try to repair your own heat pump, you might kill yourself or destroy your heat pump... only a fool would proceed.

* * *

Before you mess with your heat pump unit, be absolutely sure that power has been cut. Turned "OFF" is not good enough.

The capacitor thing isn't rocket science. The capacitor is there to give the single-phase compressor an initial startup kick... after that, it does nothing. In general, all compressors of a particular Tonage rating (1/2-Ton, 1-Ton, 3-Ton, etc.) and the same voltage (110v, 220v) should be pretty much the same, so their starting capacitors will be pretty much equivalent.

If you can get hold of a parts list for your unit, it will spell out the correct part... that is the part it should have.

Otherwise, the capacitor specs are dictated by the compressor's requirements. That compressor would be used in many different heat pumps, all of them using pretty much the same capacitor. The capacitor call-out for any of them should do it.

In many units, the same capacitor will be doing double duty to help the compressor to start and also to help the fan to start, so it's really two separate capacitors of different sizes in one can. There is the possibility that your previous repairman switched the leads incorrectly. I would think that the smaller capacitance should go to the fan and the larger capacitance should go to the compressor. You could follow the wires to see where they go to. If you are sure that the capacitor was correctly hooked up correctly, copy that hook-up. If you are not sure, find a schematic.

As a last gasp, the cap will be specified by it's capacitance and also for it's voltage. you might get one for a higher voltage... the capacitance should remain the same (assuming your tech got that part right).

So, you really need to find out the correct part call-out before you start subbing in different parts.

Finally, and least likely, your compressor could be dying and drawing too much current... in which case, it should be given a proper burial...


Attached Images
I'm not an HVAC technician. In fact, I'm barely even a hacker...

Last edited by AC_Hacker; 04-06-13 at 04:52 PM..
AC_Hacker is offline   Reply With Quote