freds49
Jun 28, 2010, 12:33 PM
I have installed a 4 ton Goodman 16seer unit using 410a. I tried to follow the book on this installation. Run gas through the pipes while brazing. New copper, 1 1/8 on return. Pulled a vacum to 40 micro, my hoses kept leaking so I used all copper pipe from guages to vacuam pump, 410 tank, to unit, took 30 hours to pull this, had 72 feet of pipe each way. I began to fill the unit with 410 and reached 150 pound of pressure. I was called away from the job becoause of family sickness, did not return for 2 weeks. The pressure was holding at 150, but my understanding is about 165 pound is needed. I also understand only one top off is allowed with 410. The unit has NOT been disconnected from the original setup. Is a top allowed at this point? The unit has/is operating at this time.