Have I missed anything?

[jimkochan]

Builder installed, 6 year old Trane Model 2TTR2060E1000A, R-22, Split Unit, Gas Pack., 3/8 X 7/8 line set approx. 26' to 30'. No line dryers or filters. OSA ambient was 110 DB. High side: 325 PSIG. Liquid line temp 98 deg Low Side: 50 PSIG Suction Line Temp 85deg. So, way high super heat and high subcooling. Compressor amps: 23.Plate FLA=25. Inside DB was 89* No WB taken to this point.
1> Found flood back to the compressor on arival and totaly clogged return airfilter. Replaced filter,flood back stopped, no change in pressures. Cleaned outside coil.
2> Unit ran for a while and compressor goes out on thermal OL.
3>Cool compressor with ice to be able to restart and head to attic to check line temps looking for retrictions. Pressures are the same on restart.
4> No line set temperature differances at the air handler. (+/_ 1 deg)
5>Find TXV bulb with insulation removed hanging out in open air at around 125 deg.
6> Re-attached and insulated TXV. No changes to pressures and temps. Evap coil appears clean.

Conclusion: Pumping against a restriction. Most likely TXV, due to possibly clogged screen (no filter/dryers and most likley did not use nitrogen when brazed-in during installation) or lost bulb charge, etc. Some one removed the bulb to get cooling at one point in time and left it that way. Is there anything I'm missing?

[udarrell]

Builder installed, 6 year old Trane Model 2TTR2060E1000A, R-22, Split Unit, Gas Pack., 3/8 X 7/8 line set approx. 26' to 30'. No line dryers or filters. OSA ambient was 110 DB. High side: 325 PSIG. Liquid line temp 98 deg Low Side: 50 PSIG Suction Line Temp 85deg. So, way high super heat and high subcooling. Compressor amps: 23.Plate FLA=25. Inside DB was 89* No WB taken to this point.
1> Found flood back to the compressor on arival and totaly clogged return airfilter. Replaced filter,flood back stopped, no change in pressures. Cleaned outside coil.
2> Unit ran for a while and compressor goes out on thermal OL.
3>Cool compressor with ice to be able to restart and head to attic to check line temps looking for restrictions. Pressures are the same on restart.
4> No line set temperature differences at the air handler. (+/_ 1 deg)
5>Find TXV bulb with insulation removed hanging out in open air at around 125 deg.
6> Re-attached and insulated TXV. No changes to pressures and temps. Evap coil appears clean.

Conclusion: Pumping against a restriction. Most likely TXV, due to possibly clogged screen (no filter/dryers and most likely did not use nitrogen when brazed-in during installation) or lost bulb charge, etc. Someone removed the bulb to get cooling at one point in time and left it that way. Is there anything I'm missing?

Well, R-22 at 110-F OAT & 325-psig is SCT of 137F - 110 is 27F temp rise; 6 year old should not be running at a 27F temp rise off the condenser coils.

What SEER is the unit?

What is the compressor amp-draw, & temps of compressor & its discharge line to the condenser.

Could be way over charged with very little area for the hot discharge vapor to condense.

A restriction at the TXV screen could have led to these other errors...?

[jimkochan]

Unit is 12 seer, the amp draw as originaly stated is 23 amps for a plate listed 25 FLA. Since the thermal cut off is 220 Deg the compressor temp. reached that without question. I'll have to try to get a discharge temp. since this is a TXV sytem why is there no change in Evap pressure whether or not the bulb is attached to the suction line or in free 125 air?

[udarrell]

Inlet screen may be partially plugged & TXV maybe wide open...?

[youngtech]

LLT lower than outdoor ambient?

[udarrell]

LLT lower than outdoor ambient?

Could there be a partially plugged liquid line filter-drier inside the unit...?

[youngtech]

pretty sure Trane has one

[jimkochan]

LLT was 98 @110 OAT, Haven't cracked open the air handler so if there is a LL filter it may be in there. Looking at the Trane TXV kits it looks like everything is bolt on extept the LL. I stopped doing this stuff about 7 years ago and got rid of the equipment so I'll have to call someone in. i still have my gauges and temp meters, but no vac pump or recovery. Could i use the factory valves to pump the unit donw and isolate the charge in the condenser? I think most of it is there already... and i think I can borrow a pump from the old boy network.