HvacTech2 wrote:
Hi cowboy, hope you are having a nice day
Subject: Suction in retard, Liquid at 175.

Hmmm my guess... OP, those reading were taken with the unit not
running... and if it has pure R-22 in it, the temperature of the
equipment that day was about 95F, is that right?

Got that info from the "vapor pressure scale" on my gauge set.

c From: "cowboy"
c there is no other way to accurately determine the correct charge,
c other than weighing it in, no matter what any contractor might
c incorrectly tell you.

Actually there is a way to check the charge properly. depending on
the metering device superheat or subcoooling. weighing the charge
in is a start but you should always check with the proper method
above to insure that you are correct.

Yeah cowboy, what HvacTech2 said. :/

I'm still in the process of getting a handle on this super-heating
and sub-cooling thing myself. It's kind of tricky but is "the way"
the engineers figured out what the charge weight should be to start
with. First things first. Know what I mean, Verne?

What I want to see is an explaination on how to measure and adjust
SH and SC using only the pressure readings, the R-22 scales on the
gauges and a thermometer.

Definition basics to get out of the way:

Water boils at 212F at one atmosphere of pressure.

The heated-boiling pan of water stays at that temperature only the
vapor/gas can be brought above that 212F so water vapor/gas at 220F
(and one atmosphere pressure) is super-heated 8F.

Sub cooling: Water at 200F is 12F subcooled (at one atmosphere
pressure). Different pressures, different boiling points, different
numbers.

To measure SH and SC you got to know (what the liquid really is and
so its characteristic boiling points, at what pressures and also the
existing/measured temperatures and pressures.

With that, we are getting dangerously close to my limit of knowledge
on the subject. (assuming I even got it worded right)

Alvin in AZ
ps- where you at cowboy?
pps- my first post here on a.h.r!