R12 Subzero 532 issues

[dbur]

I have a subzero 532 from 1991 with R12. The condenser fan failed in 1998 and the fridge compressor failed. The compressor was replaced, but I've had poor performance with the fridge ever since. I have low and high side ports on this system and am thinking the best case is the charge was never sufficient and I can just hook up a manifold and check it and up the charge if needed.

Here's the nameplate if this works:
photos.app.goo.gl/JJr7v9tY9oW3ohs38

Well I guess I'm not allowed to post images or links, but only one design pressure is given for both the freezer and refrigerator section. 235 hi 140 lo.

Subzero tech support says my charge pressures should be 16/120 fridge and 4/120 freezer, and they claimed they never printed those numbers on their nameplate (they did). I assume those are to be with the unit acclimated to room temperature and compressor on only briefly.

I plan to order some R12 and be prepared to charge it up when I connect the manifold to check pressures.

Any comments on this unit and how I should do this?

Is there any way this can be properly converted to R12a? My local (Subzero listed) repair guy says he just changes them to 134a, but Subzero says no never do that. R12a seems really good, but I would probably need someone to come evacuate the R12 before doing that.

Thanks.

[WT70]

If you don’t understand the difference in design pressure and refrigerant charge, shouldn’t you call someone to take care of it for you?

And why wait almost 22 years to check it?


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[ammoniadog]

Those pressures listed on the name plate are "test pressures", which basically means the maximum pressure those parts of the system can hold without exploding.

No other refrigerant will work as good as R12 did. I don't know what the proper procedure would be to change it to R12a, and even if I did, we aren't supposed to be giving this type of advice to people on this forum, except for in the locked areas that are reserved for licensed professionals. Sorry.

[BBeerme]

I'd be willing to bet that someone did a leak check and repair then put in a different refrigerant due to the cost of R-12 (you can thank your government for that). It is also possible that your unit has more than one type of refrigerant in it now (not good).

Your unit can be converted to a current refrigerant, but to do it properly, you would probably be surprised at how much it would cost. Typically, a 30 year old unit is only converted if the new one cannot fit into the same space.

If you are trying to save some money, my recommendation would be to look up some second hand shops that are selling used equipment. Where I live, that used to be a thriving industry, and the sellers would typically give you a 90 day warranty. Not bad considering the great reduction in price from new equipment.

I have a subzero 532 from 1991 with R12. The condenser fan failed in 1998 and the fridge compressor failed. The compressor was replaced, but I've had poor performance with the fridge ever since. I have low and high side ports on this system and am thinking the best case is the charge was never sufficient and I can just hook up a manifold and check it and up the charge if needed.

Here's the nameplate if this works:
photos.app.goo.gl/JJr7v9tY9oW3ohs38

Well I guess I'm not allowed to post images or links, but only one design pressure is given for both the freezer and refrigerator section. 235 hi 140 lo.

Subzero tech support says my charge pressures should be 16/120 fridge and 4/120 freezer, and they claimed they never printed those numbers on their nameplate (they did). I assume those are to be with the unit acclimated to room temperature and compressor on only briefly.

I plan to order some R12 and be prepared to charge it up when I connect the manifold to check pressures.

Any comments on this unit and how I should do this?

Is there any way this can be properly converted to R12a? My local (Subzero listed) repair guy says he just changes them to 134a, but Subzero says no never do that. R12a seems really good, but I would probably need someone to come evacuate the R12 before doing that.

Thanks.

[pecmsg]

Good Luck and God Bless

Call someone that knows what there doing!

[BBeerme]

Beat you to it by five seconds, LOL

Good Luck and God Bless

Call someone that knows what there doing!

[2sac]

The million dollar question is If it was repaired 22 years ago and has performed poorly for 22 years, why all of a sudden do you want it fixed now?

[dbur]

It is a built in and I can't remodel my kitchen for another unit. Also even a used unit is asking almost as much as I paid for this new. $ are tight this year so I can't be blowing 1000's of $ on this when maybe just a top off of R12 will make it serviceable again. Not sure I'd want another Sub Zero again anyway after the myriad problems I have had with this one. Even my 40 year old $200 Sears unit is still working fine. So my only real option is to get this one operating effectively again. I've contacted a few pro's and one didn't want to touch an R12 system, another said he would just charge it with 134a (he was a subzero listed service provider). Sub Zero tech support says in no way do that. So my options are find some R12 and and top off and hopefully get lucky, get someone to do a full evac for me and move to an alternate coolant (Sub Zero says 414a or b). R12a seems a better option but not many service people in US are familiar with it. (R12a is much more efficient than 134a and more compatible with R12 systems). I could give a link to an engineering journal comparison but I'm not allowed to post links here.

[BBeerme]

Probably due to the [unqualified] techs that you have been calling. Trying to go cheap.

Haven't looked at your profile, but where you are doesn't display on your posts. Tell us where you are, and maybe there is someone local here to your area.

Gonna have to pay though.

It is a built in and I can't remodel my kitchen for another unit. Also even a used unit is asking almost as much as I paid for this new. $ are tight this year so I can't be blowing 1000's of $ on this when maybe just a top off of R12 will make it serviceable again. Not sure I'd want another Sub Zero again anyway after the myriad problems I have had with this one. Even my 40 year old $200 Sears unit is still working fine. So my only real option is to get this one operating effectively again. I've contacted a few pro's and one didn't want to touch an R12 system, another said he would just charge it with 134a (he was a subzero listed service provider). Sub Zero tech support says in no way do that. So my options are find some R12 and and top off and hopefully get lucky, get someone to do a full evac for me and move to an alternate coolant (Sub Zero says 414a or b). R12a seems a better option but not many service people in US are familiar with it. (R12a is much more efficient than 134a and more compatible with R12 systems). I could give a link to an engineering journal comparison but I'm not allowed to post links here.

[2sac]

R12 currently sells wholesale for $2300 for a 30 pound jug. There are other R12 replacements but all are pricey. I find it difficult to believe that a compressor that has run on a low charge for 22 years has suffered zero internal damage.

[dbur]

Location is Oregon. And I haven't been talking to cheap providers. The one guy who wanted to do 134a is actually a Subzero approved service tech.

[stumpdigger]

I have a number of ideas; do not have it changed to R-134a, don't attempt to do anything yourself, not necessarily in that order. No one built your house around the refrigerator, it will pull right out. Hire a professional, there are links on this site.

[pecmsg]

Location is Oregon. And I haven't been talking to cheap providers. The one guy who wanted to do 134a is actually a Subzero approved service tech.

To convert to 134A requires a new condensing unit, evaporator(s) and metering device. If there going thru all that might as well go R404A

[Pnasty]

To convert to 134A requires a new condensing unit, evaporator(s) and metering device. If there going thru all that might as well go R404A

My vote is 290 and an open flame.

[BBeerme]

290 and a flame won't do anything.

If you really want some action, you need to add some oxygen.

Okay now, where's my beer . . . Need to sit back and wait for the Fireworks . . .

My vote is 290 and an open flame.

[stumpdigger]

290 and a flame won't do anything.

If you really want some action, you need to add some oxygen.

Okay now, where's my beer . . . Need to sit back and wait for the Fireworks . . .

Maybe go real old school with a SO2 unit...

[stumpdigger]

Consider calling the local union and getting a commercial refrigeration guy to come out.

[pecmsg]

Consider calling the local union and getting a commercial refrigeration guy to come out.

We charge too much

[stumpdigger]

We charge too much

as in "overcharging" In the long run we would be way cheaper.

[pecmsg]

as in "overcharging" In the long run we would be way cheaper.

Exactly