R22, 6 ton light commercial straight cooling RTU, 1 month nearly new Danfoss scroll compressor, previous tech also converting the original fixed orifice to TXV two weeks ago, cleaned evaporator and condenser coil, blower and OD fan motor in normal operation. 80F outdoor dry bulb, condenser fan rejecting air temp 95F. AC return air 75F, supply air temp 65F at register outlet, discharge pressure 215 psi, discharge temp 229.8F, suction pressure 101psi, with 4F superheat 6 inch before compressor. 21F subcool. compressor is running at higher than normal temp. Now come to the question, will a faulty TXV cause high suction pressure due to stuck open like 90%? no matter how to adjust the superheat, nothing happen to the low side pressure. need some advise here, thanks.
Sounds like a bad compressor to be. With a flooding txv u will have high discharge and low superheat. Could try slowing down the blower or running it with no blower to see if suction pressure is still really high.
Interesting ha, talked to owners cousin(new hvac tech)he ordered this compressor from eBay last summer, never had it run after installation until last two weeks, work fine for 4 or 5 days. After that high suction pressure occurred and dont know why he convert fixed oriffice to txv, but got no luck, high suction still exits after conversion. Ok
Typically we also like the model and serial number for the unit in question and the label information from the new compressor might also be helpful along with information about the TXV itself.... from its label.
Which refrigerant is the original refrigerant for the unit from the manufacturer, and is a different refrigerant being used now?
[Avatar photo from a Florida training accident. Everyone walked away.] 2 Tim 3:16-17
Typically we also like the model and serial number for the unit in question and the label information from the new compressor might also be helpful along with information about the TXV itself.... from its label.
Which refrigerant is the original refrigerant for the unit from the manufacturer, and is a different refrigerant being used now?
Sounds like the conversion is the culprit. The new distribution header should have an orifice, sized for the tonnage. Also the distribution tube size, and number of tubes Needs to be sized for the correct pressure drop. Got any pics of the conversion?
Sounds like the conversion is the culprit. The new distribution header should have an orifice, sized for the tonnage. Also the distribution tube size, and number of tubes Needs to be sized for the correct pressure drop. Got any pics of the conversion?
Had a chance talked to the owners cousin who handled all related repairs to this unit. As he mentioned, high suction pressure exists before he did the conversion, but nothing improved. He is concerned about overheat the TXV when he did the brazing. Distribution feeder was 100% home made. 12 circuits at equal length 0.046 ID. But assuming these distribution circuits are oversized, how could you explain high discharge temp.
Reply
Originally Posted by jumstar
