It is a WIF. Recently I have welding repaired the condensing unit for that. So much gas leaked away, there is not enough gas inside. But I couldn't figure out the refrigerants inside.

It is Hussmann condensing unit. The attached label indicate it is R12 unit. But I found compressor is R502 unit(model: Copeland semi hermetic, EAD1-0200-TAC), and also found TXV is GRE-1-ZP(R404, 507, 502). There is Large printed letter on c/u - R12".

I wonder if there is R12 or R502 inside the unit!
I am lost. Please help me with this matter.
R12 can be used for R502 compressor with R502 TXV?.
It is low temp unit and worked well for 15 years with almost no issue.