What refrigerants is inside?

[jayryu]

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.

[AlexG]

Check pressure & outside temperature.

[Brian_UK]

You cannot use R12 any more, it is illegal.

Match the TXV gas.

[jayryu]

Can you get R12? It was stopped production 20 years ago.
Pressure wise it seems R12. TXV is R404/R02. but I cannot ignore the nameplate of manufacturer too, that is R12.

[jayryu]

I've forgot , low 25~ psi, high 200 psi. box temp 35 F, sight glass: 1/2 stable and clear with barely moving.

[monkey spanners]

Being low temperature application, the TXV being R404A/R502 and the compressor similarly so all points to it having R404A or R502 in it originally. The rest of the condensing unit won't care what refrigerant it has in it so long as its components are rated for the pressure and duty.

Pump the system down, disconnect the compressor electrically but run the condenser fans till the condenser and receiver reach ambient temperature, measure the refrigerants pressure and look it up on a PT chart, it will point you in the right direction as to what is in there.

It would make sense to recover and start again with a fresh charge.

[jayryu]

I have recovered all the gas inside and freshly charged R422A. It works fine till present. Thanks.

[hvac01453]

now you have another problem, tell the supplyhouse what the gas is...They wont kow and will wack you good to dispose of the stuff. keep the cylinder in the house or basement with a thermometer for a day and then read the pressure of the cylinder. compare it to a PT chart to ID thje gas. It is likely 502 if its low temp(freezer). R12 started phasing out 7/92 and 502 not long after.