[tmuller13]

I have a 1992 Rheem RAKA-042JAZ 3.5 Ton Air Conditioning Unit that has a Copeland Scroll Compressor ZR42K3-PFV-230. The compressor tries to start (a 2 second hum) then stops. Then 25 seconds later, tries to start (a 2 second hum) then stops, etc...
The fan motor works fine and spins freely when triggered. I replaced the Dual Run Capacitor (60/5 mfd 440) and added a Kickstart KS-1 Hard Start Kit for 3.5 - 5 ton compressors and it still won't kick over. I've tested with my VOM the compressors C-S, C-R, R-S terminals. All equaled up correctly. Ran a scratch test (for ground outs) off the compressor and no continuity issues. Contacter Block is fine. Pulls down when triggered and no problems. So it seems the electrical side of the unit is OK.
Does this Copeland Scroll Compressor have a built-in protection which could be causing this lock up due to a lack of R-22 or am I going to need a new compressor? I know the AC unit is old and probably at its End Of Life but this house is going to be foreclosed on and I need a "band-aid on a bullet wound" for the next 90 days. Thanks so much for your help...

[Grady White]

It sounds like the compressor is stuck. If you have a clamp-on type ammeter, clamp it around one of the incoming line voltage wires. My guess is you will read locked rotor amps when the compressor tries to start. The locked rotor amps should be on the equipment lablel.