Compressor internal thermal cut out

[paul_h]

Got an old system I changed the compressor in about 2 years ago.
Worked fine until a week ago, now I think the compressor is faulty, any ideas though?
R22 system, recip kirby/tecumseh compressor (AV190TT-051-A4 or AVB5558 EXG - don't know which one is the model# )

36C ambient, went open circuit due to internal temps.

LP 780kPa
HP 1700kPa
These pressures were at the end of the day when taking temp readings after it cut out once already. Before the first cut out and it was cooler, LP was 600kPa and HP was 1500kPa)

indoor air on/off 28/23C
Outdoor air on/off 36/42C
Suction temp 20C
Discharge temp 106C

Capillary heat pump ducted system, no service valves (for example to close liquid line)
Refrigerant was charged by me so nothing wrong with the charge.
Maybe reversing valve, but temps around it don't look too bad:
Reversing valve suc in 21, suc out 24C, discharge in 106C, disc out 102C

Compressor noisier than I would expect, sound under high load, but amp draws were normal (6A per phase, about what you'd expect) Mains voltage was fine too, getting 238V from each phase and 410v across them at the compressor)

[mikeref]

Paul h, AV190TT rings a bell, think its a 5HP compressor. I have two in a Lennox ducted a/c. Stage one compressor has been replaced twice in 8 years. Once as the sump heater burnt out. Been mechanical problems, and now when the latest one starts, it rattles badly and compared to stage 2 compressor... it should already be dead. Can't recall pressures but amps/phase was around 6.8 to 6.2 on 411 volts.

[Tesla]

Hi Paul
Check for a hotter than normal compressor for the valve problem. On R22 capillary systems I found a few that have operated under hot conditions the capillary blocks up so if you end up changing the comp it would be worthwhile replacing the capillary too. RV sounds OK but you know they can be temperamental. Is there staging on the cond fan/s?

[paul_h]

Yeah I thought compressor myself the very second I was on site. high suction pressure points to compressor valves.
Just hoping I was wrong as this is a client of mine that will be p1ssed, considering the compressors aren't cheap, and it's on a 2nd floor roof, so expensive to change over. Had enough problems already frankly and he's not going to be happy. :(