Cold Plate Kaput

[sneuman]

My refrigeration unit is not working properly. Although the compressor seems to be working fine, but the cold plates aren't cooling. Should I assume the cold plates are indeed the problem and order replacements, or would it be wise to pay an expert to look it over first?

[Vasco]

You might have lost some of the freon. Check it out with a set of guages first before you start replacing plates.

[RaptorDance]

Yes, the most likely cause is a loss of refrigerant. Unless your fridge is really old, it probably does not use Freon. Possibly 134a, your manual should be able to tell you.

A good repair person will not only have gages, but also a leak detector. If you're fridge just stopped, you have a bad leak. If it slowly degraded, you have a slow leak. Either way a leak detector is in order.

If you just refill the refrigerant without fixing the leak, it's most likely will just leak out again.

It's unlikely there's anything wrong with the holding plates, unless you have a refrigerant leak at one of the fittings.

Regards,
Bill

[Vasco]

It's a Tayana 37, probably needs R12!!! Can still get it in the Bahamas.

[RaptorDance]

The fridge may not be the same age as the vessel.

[RaptorDance]

Also, I believe that Tayana is still making 37s. So it could be a new boat.

[sneuman]

Originally Posted by Vasco

It's a Tayana 37, probably needs R12!!! Can still get it in the Bahamas.

It's a 1978 and almost certainly the original refrig system. Is R12 really that hard to get? If so, could a new set of cold plates be swapped easily for the old? How much do those suckers go for?

[RaptorDance]

Check locally, R12 is very hard to get in the US.

Check with a local service person to see what a conversion will cost and take. Most likely you will need a new compressor. The tubing and cold plates are about the only part's you DON'T need to replace.

[Vasco]

R12 cannot be sold to consumers in the US. I think this has been in effect since the early nineties. You used to be able to buy it in little cans. I have a couple in my basement that I got in the Bahamas for my CS36 Merlin (1988). I think refrigeration technicians can get it in big cylinders but I might be wrong. The old compressors will not work with 134A. That's the problem, not the holding plates. The funny thing is that scientists now believe that freon didn't have much to do with that big hole in the ozone, the original reason for banning it.

[GordMay]

Originally Posted by Vasco

... The old compressors will not work with 134A. That's the problem, not the holding plates. The funny thing is that scientists now believe that freon didn't have much to do with that big hole in the ozone, the original reason for banning it.

Goto: Refrigerant Properties
Refrigerant Properties

[sneuman]

Originally Posted by Vasco

R12 cannot be sold to consumers in the US. I think this has been in effect since the early nineties. You used to be able to buy it in little cans. I have a couple in my basement that I got in the Bahamas for my CS36 Merlin (1988). I think refrigeration technicians can get it in big cylinders but I might be wrong. The old compressors will not work with 134A. That's the problem, not the holding plates. The funny thing is that scientists now believe that freon didn't have much to do with that big hole in the ozone, the original reason for banning it.

SO, what would the specs be on a compressor for 134a? Just curious: what is so different that it would require a switch to a different one than used in an R-12 system?

[RaptorDance]

I'm not completely sure what the differences are in the compressors. I think it's more though than just the differences between the lubricants in the refrigerant. I think it has to do with differences in the refrigerant's "heat cycle" and possibly corrosion properties.

see Refrigerant - Wikipedia, the free encyclopedia

[sneuman]

Originally Posted by RaptorDance

I'm not completely sure what the differences are in the compressors. I think it's more though than just the differences between the lubricants in the refrigerant. I think it has to do with differences in the refrigerant's "heat cycle" and possibly corrosion properties.

see Refrigerant - Wikipedia, the free encyclopedia

Thanks. I guess I need to do a bit more research.

[Alan Wheeler]

Hi Scott, the compressor should be OK to use with the new R134a. It is the oil that is the important part. The oil is different to the oil used with R12.
The fault in the system could be one of several things. If the compressor is sealed (totaly electric) then it will be a gas loss due to possibly a leak in a copper tube or plate. If it is engine driven, it could be the same, but with the added possible of a seal failure around the compressor drive shaft. It doesn't have to be bad enough to see oil leaking, the gas can still escape. This is most common in situations where the unit does not get used regularly.
Another possible is the Drier. Once again due to the shaft seal, moisture can also get in. It only takes a little over time and enough eventually builds up to overcome the drier and then the Ice will block the system up.
Trying to find a leak is difficult. The first thing someone needs to find out is, does the system have gas. If it doesn't, then the second step is to introduce gas with a special dye. This is because finding a leak is not always simple and a refrigerant gas detector sometimes will not detect the tiny amount leaking. The dye leaves a mark at the leak that is seen with a UV light.
If a major overhaul is required, then you have to have a new drier installed, new gas, new oil and so on.
It is good to get to learn this stuff. It is probably the most common of breakdowns among a sailign community and the one leaset likely to find a knowledgable person on. Have that knowledge can help with making many friends. And maybe even a replenishment of the cruising kitty. I am still learning, but have gained a lot of knowledge from just a short time ago when I asked could I put LPG into my AC unit :-0

[Pblais]

You may be able to find the leak and effect the repair. If it is an old fridge it may be time to part company after 15 years or more you don't get much more time. Leaks are not usually a one time event.

If you have one part either cold plate or compresor gone bad I would replace them both. When they reach an age of 15 or more years old they won't both last another time around so when the other one goes it will take the other.