OK.... I checked the run capacitor and it measured 35uF; well within 10%
tolerance. My AC guy called me back and came by and found that the system
was 2 lbs low on freon. After charging it, it's run fine since 5:30 and the
compressor has NOT cut off. It was 84 in the house and 5 hours later is down
to 78. When he was here he measured the return air at 81 and the supply at
68 at the registers. Tomorrow when I go to work I'll just cut it down to 76
and see if the house is cool when I get home.



"unix-freak" wrote in message
om...
"Travis Jordan" wrote in message
om...
Travis Jordan wrote:
unix-freak wrote:
It is also possible that the compressor is overheating and shutting
down on overtemperature. If the system were just low on
refrigerant (and it had an auto-reset low-pressure switch installed,
a feature seen mostly on high-end systems) then indeed it might
restart after 10 minutes. How ever, I wouldn't risk compressor
damage if I were you.

Tomorrow morning call one of the local HVAC distributors and ask the
counter person for the name of a really good technician that they
would have work on their personal system. Johnstone Supply will do
if you have one in the area, or find the distributor for the
manufacturer of your system.

OK..I've got a guy coming out on Friday to check it out. To tell you
the truth, I think it was already low on freon when the other guy was
out last Thursday and when he disconnected his guages, he didn't do
it quick enough as freon came pouring out on the high side. I
didn't have the compressor cutting off problem prior to this. The
fan still runs at the blower and compressor so I don't suspect that
there's anything wrong with the thermostat.

Let's hope he is a tech who understands the mechanics of the
refrigeration cycle and that he isn't just a 'parts changer'. I
encourage you to ask him how he plans to diagnose your system's
performance. Here's some background reading so you can be prepared to
have a knowledgeable discussion.

http://hvac-talk.com/vbb/showthread.php?threadid=33829
http://www.hvacloads.com/talkpdf/charge.pdf
http://www.hvacloads.com/talkpdf/tro..._superheat.pdf

One more thing; you may want to do a Manual J (heat gain / loss)
calculation to see what your system size should be. This is the only
reliable way to figure out what BTU (ton) rating you need for adequate
cooling and heating. I've had good luck with the (old) Lennox Load
Calculation software, available for free download at
http://home.att.net/~alt.hvac/loads.htm

Very cool. Thanks for the advice and resources.
You can't be to careful. I trust very few when it comes to certain
things such as this. That's why I do all of my own auto repairs, home
repairs....electrical....and the list goes on. Unfortunatley I won't
be there when he's there Friday morning. My wife referred me to this
company because her mother uses them and she's gotten good results
with them.