[kuehl]

Brad,

Is the bass fishing really as good as they claim down by you?

Back on the topic of the moderator's initial post.... my 2 cents are based upon the initial symptoms and events and his observed gauge readings: probability of ambient gases in the system and an undercharge. If you and I had been sitting there observing the procedures he undertook we might arrive at a different conclusion.

Have I seen TEV's (expansion valves) malfunction because of moisture? Yup.
How often have I observed this in the past 30 years? Hands on working with client's vehicles at our shop, at least twice per year but more common on with 911 and 930's because they have 40 feet of hose and 2 condensers. Helping 'experienced' auto repair shops trouble shoot the same issue over the phone, at least 6 times per year. Helping DIY's over the phone, a dozen times per year. Why does this happen? Well, with the experienced auto tech's many don't realize the volume of the system, say on a 911/930, and the need to purge with nitrogen or refrigerant gas a few times in the evacuation process. With DIY's the causes vary between simply not pulling a vacuum, use of inexpensive equipment (faulty gauges, service set's with loose connections or leaks), not understanding how the service set works, failing to install an o-ring or shearing an o-ring, allowing air to enter the service set while swapping cans, etc.

Getting back to the pressure differentials observed, 50/120 at 70F relative to an automotive system, and assuming the gauge readings are correct (user knows how to use the service set), and assuming the new compressor is good: the system in undercharge and likely has ambient gases (air) inside. But, you never know.
I've seen client's (experienced tech's and DIY's) call us back a week later "Oh, hey, my bad, I installed that new compressor you shipped down and it was not the compressor".

We don't do home, commercial or industrial systems normally, but I have helped a few people along the way, such as last year when the local HVAC guy left 2 kids at my place to finish off installation of a new comp/cond unit outside my place; the 2 kids did not realize the unit arrives with a charge, and amusingly the 'object' they found in the old cabinet, left by the previous service tech was his electronic sniffer!

Cheers,
Griff