That's right - I'm working on a 25+ year old Rheem PCA-030. Does anyone have any of the old installation manuals for this. Near as I can tell this was a package that was re-worked in the field (no excess lineset coiled in the attic). It does have an accumlator, and is an old capilary (no txv) system. Evaporator coil looks new and outdoor coil is clean too. Airflow is good and hard-line ducts are actually insulated! System has a very slow leak at the accumlator output stub where they tend to rust out. Compressor is a Copeland CRG1-250-PVF with a failed crankcase heater. I'm trying to use the original charge table (superheat) from the condensor cover, but it doesnt make any sense at all. I'm hoping someone here with a lot more experience than me can help me sort it out. I suspect the system is overcharged, but the table seems to say it's undercharged. So here's some numbers:
Outdoor ambient: 70
Static preasure: 125 (its R22 of course)
In cool mode:
Suction side service port entering condensor: 57psig
Suction side temperature between acc and cpr: 38f
accumlator and suction lines are all happy sweating.
18f drop across evaporator
In Heat mode:
355psig measured at evaporator
36f rise across evaporator (78f at return 114f at supply)
I dont work on these old systems and its unusual for me to see head preasures this high - but I'm willing the accept it might be near normal for this old girl.
The stumper is the Rheem superheat chart says for 70f od at 57psig I should have a suction line temp of 74f! The chart instructions say anything to the left of that (which I am of course as the suction line is about 38f and sweating), says I'm low on charge.
Can you old timers chime in here and teach a young buck a thing or two? How on earth can this old Rheem charge chart be right? What am I doing wrong?