High liquid line temps
High liquid line temps
(OP)
A few of my co-workers are in a discussion about causes for a high liquid line temperatute og an A/C and or refrigeration system.
A few of the causes that they list that I don't argee with are :
1. Over charge
2. Bad Valves
3. Partially clogged cap tube or defective TXV
As for over charge, I am telling them that the LL temp will lower as you increase the charge in the system due to a slower velocity of the refrigerant in the causing more hang time in the condenser.
Any one agree or disagree?
Jim
A few of the causes that they list that I don't argee with are :
1. Over charge
2. Bad Valves
3. Partially clogged cap tube or defective TXV
As for over charge, I am telling them that the LL temp will lower as you increase the charge in the system due to a slower velocity of the refrigerant in the causing more hang time in the condenser.
Any one agree or disagree?
Jim





RE: High liquid line temps
The normal cause of a high liquid line temperature is a dirty condenser coil
RE: High liquid line temps
Regards,
RE: High liquid line temps
An overcharge will not necessarily cause a high LL temp. The way I was taught it that you will have a higher than usual LL temp during an undercharge with a TXV with a higher sub-cooling. As you add refrigerant the subcooling will decrease until you hit the mfg's recomendations. As you continue to add refrigerant ythe subcooling will continue to decrease.
Jim
RE: High liquid line temps
If the system used a TEV, however, one could expect it to control superheat, even if the system were substantially overcharged. In this case, condenser pressure and temperature would be expected to climb as we continue overcharging the system.
But at some point, even the compressor would lose enough capacity due to overcharging to limit condensing pressure and temperature, even if superheat were to be maintained. Here, I would expect to be at some nosebleed area above the high pressure cutout.