Randy Roberts wrote:

I have three 18 year old carrier units. I was checking R22 pressures on
all. Scrader valve apprarently stuck open and leaking on unit #3. The
next day I found cooling fan running with compressor not running but
bubbles comming out of scrader valve on suction line. I checked
pressures on high an low side, both about 125. The next day I installed
manifold gage and started unit. The suction started to drop and I open
the R22 supply. Pressure dropped to about 80 when compressor stopped
running. The fan kept running very slow. Checked 220 line and found lug
on panel beaker melted away from buss bar. Replace mini 220 beaker with
full size 220 breaker. When stating system the condensor fan runs slow
until contactor closed by thermostat then fan runs full speed. The
compressor tries to start but fail after 3 seconds. The system was
running and cooling well before I tested the pressures. At least it was
running better than the other two units.

Here are my questions:
1. Is there a low level freon cutout switch shutting the compressor
down?

Not at 80psig.

2. Did a loss of freon and or oil cause the compressor to seize?

Could've been that, or maybe a slug of liquid from somebody randomly
dumping in freon.

3. Did the faulty breaker cause the motor to sort-out or did a high
current from low freon overload the breakers or both?

Possible, not likely, but possible.

4. What do you recommend?

Two things:
1) A new unit
2) That you quit while you're ahead.

Why would you be checking pressures when you obviously know nothing
about air conditioning systems. What good is knowing the pressures when
you don't even know what they mean? You don't just dump freon into a
system on a whim, hell you probably caused every bit of the problems. I
recommend that you call somebody competent to check the systems
periodically; it'll be less expensive for you in the long run.

hvacrmedic