it only takes 85% of what the system needed for r12
which is a max of 24 oz +/- an ounce or so. You way over filled the system. The switch is a dual high/low switch. It will stop the compressor if there is less than 30 psi, or more than 294 psi I believe.

 

Well then I guess I need to get a gauge that actually works so I can tell how much is in there. I thought I let enough out but maybe not. I'll try again tomorrow and give an update