[hvacrmedic]

if a system is properly charged on start up and then the txv fails you have high sub cool and high superheat if he added refrigerant to get the proper sub cool then either the unit was not charged correctly on start up or the refrigerant leaked out.if the tech that replaced the txv followed proper procedures then the system should leak free

A restriction at or within the metering device will cause a drop in SC.

 

[hvacrmedic]

Thank you! I was gonna say the same but you beat me to it.

Hey folks, if you ever hear anyone dissing "all that refrigeration theory crap", tell them to take a long walk off a short pier.

The problem is that some of the theory presented is wrong. We hear things like "SH and SC tell you where the refrigerant is in the system.". Well that's a nice thought. It is however a misguided thought. With a complete restriction at the MD all of the refrigerant gets trapped in the condenser and LL. Nevertheless the SC will stabilize at exactly 0.