What kind of refrigerant???

[agrosalmon]

I've got a 12v "Magma Cold" compressor on my project boat and I'm wondering if any one knows the type of refrigerant to recharge it with. The 12v compressor shares a condenser with a 120v compressor as well. I couldn't read the name plate on the 120v one though. any thoughts?

[deniseO30]

Age has allot to do with type. 12 was phased out in the early 90s (CRS here) most likely it's R-12 if it's old. An experienced tech can tell by pressure at a given temp also. 134 is not hard to mistake should you have it, it stains everything. R-12 (one reason we loved it) runs very close in operation pressures to the temps it was working at.

Just a few refrigerants used in such systems,
refrigeration, 12, 22, 409A,134 (new generation), 22 in ac systems is being phased out for 410A, 134 417A, I guess there is a "marine" standard for types of refrigerants and system designs.

409A, 404A, (not likely) "hot shot" (is a mix made for "drop in replacement of 12)

Confusing? Very! There are hundreds of types of refrigerants for hundreds of types of systems, and manufactures design around those they choose for the application. Fortunately, your only likely to have R-12 in your systems.

I'd love to see photos of your system. Dual evaporators or dual circuit?

what are the symptoms or problems? Caution.. very very common mistake, small systems like this use ounces, not pounds of refrigerant.

[shogan50]

If it is R12, I've used this stuff before. It works quite well. HC-12a - Wikipedia, the free encyclopedia. Propane is a common working fluid in European refrigerators below a certain size. The US legalities and loopholes and realized safety have been the topic of debate for a couple of decades.

[deniseO30]

I remember an old book I had that described how to make a gasoline refridge. LOL

Propane (LPG) has the same properties as freons.(change of state) gas to liquid.. to gas and back again vie compression and expansion. except it's explosive.. way way back, Your grandma's GE and others.SO2 (sulfur dioxide)
Very very large systems still use ammonia btw.

[agrosalmon]

I'm working about 3000km away from home right now so I won't be near my boat for a couple weeks. I'll take a picture of the system when I can though. It seems pretty simple though with the condensor between the two compressors. The whole system is plumbed together so I'm guessing the refrigerant is one that can work for both the 120v and 12v compressors if that helps... The system wasn't run for at least 4 1/2 years before I bought the boat this summer. Any guesses if recharging the refrigerant will breath some life back into it? Thanks for the responses. It's a real help.

[JimsCAL]

The compressor voltages tell nothing. Chances are if the units are more than about 15 years old, they are R-12. If newer then probably R-134a. But your really need to find a nameplate for doumentation to determine this. Mixing different refrigerants will create big problems, requiring recovery of the refrigerants and a complete recharge. And before you just add refrigerant, you need to find out if its undercharged. Overcharging will cause problems, even potentially damaging the compressor.