I have had this happen to me two times in the past week and I am a little confused. When charging a R-22 system with a Fixed orifice or piston I aim for a 18-22 degree superheat. I was charging a system on friday that did something really weird and it happened again today. I was charging the system Really slow...had nothing else to go do after this job. I started with a 35 degree superheat and worked my way down (around an hour) to a perfect 20 degree superheat. Awesome!! I had a perfect 20 degree split between my supply and return also. Left my gauges on the system, went to the truck and wrote up the invoice, cleaned up my area, 20 minutes later....3-5 degree superheat!!! What happened? I went so slow and took my time, I cant believe I may have over-charged the system. Someone said its because of a oversized piston allowing too much liquid passed the piston. Even after a 3-5 degree superheat I still had a 19-20 degree split between S & R so I wasnt sure what to do. Can anyone help?? Thanks!
about to start my 4th year apprecticeship..I know alot but definately not everything.