A/C cooling problem

martin

I own a duplex rental unit and am putting stand alone A/C in attic. I bought the equipment 4 years ago when companys were getting out of their R22 stuff. equipment is Goodman 1.5 T cap. I do install professionally but this is someting I've never seen. When I started up the condensing unit my low side went to 5psi, high side 150. I added some extra 22 the lines were 15' longer than factory charge,but it didn't change a thing. So I shut the unit down and it would not equalize. Anybody have an idea what the problem might be.