Trane "C" purge

[r404a]

Got a couple of questions about a 1996 vintage PRGC. This is a stand alone purge for a retrofit from an oilless or belt drive purge and it has a local human interface at the purge. It has a sensor strapped to the liquid drier shell to sense temperature and I noted a 32 degree liquid temp when scrolling through the temp menu. The purge was in the ON mode and its status was RUNNING. I have the low liquid purge inhibit set at 40 degrees. Shouldn't I have a run status of LOW TEMP- Purge inhibit by low liquid temp, or does the purge inhibit status only show up when the suction temp is low enough to purge AS WELL as having a low liquid temp? Also, is the suction thermistor in a dry well on the suction line or is required to handle refrigerant if changing out? Thanks in advance.

R404a

[drivewizard]

The low temp message only shows up when suction line temp is cold enough to initiate a pumpout.

Not sure about the suction line temp thermistor. I suspect it is in a well, but have never had to replace one so don't know.

[r404a]

thanks drivewizard


r404a

[jayguy]

the suction line thermistor is screwed into a 'tee' fitting. this fitting is open on the 'run' and it is threaded on branch but it is NOT in the refrigerant side of things.

the sensor instructions say to screw it in 'finger tight'...what they really mean is 'baby finger tight'. you can very easily strip it out and then you get to buy a new sensor. the tee fitting is copper and did not seem to strip at all (2 times in a row).

BABY FINGER TIGHT is the key phrase here...got it? BABY FINGER TIGHT!

[Healey Nut]

BABY FINGER TIGHT is the key phrase here...got it? BABY FINGER TIGHT!


So I cant use my 18" adjustable with the 4ft length of 1 1/2" gas pipe over the handle ?????........... Wheres the fun in that ?????????????

[ga1279]

Yeah, I generally use some thermo-paste on the little sensor head and threads then screw it in with my most gentle touch. They snap so easy it's not funny. Some of the original suction temp sensors were put in using Lock-Tite from the factory. I was always under the impression that the liquid line temperature was mounted on the bottom of the filter drier as the condensed liquid from the purge went back to the condenser. The set-point for low liquid temp was to eliminate needless purge pump-out operation when either the equipment room temperature dropped to low or the filter drier became restricted. The setpoint should shut the little refrigeration unit off when low temp is reached. The set-point is generally set at 40*F-GEO