r502 low temp replacement

[mikeserv]

93, 6hp low temp discuss was running on 502,
any sugestions?

[refrigman22]

A good replacement R-404a . Change the oil to POE

[citywide service]

Why not R-408?

CM

[the mojo]

Well, You have these choices: www.refrigerants.dupont.com to work with. ISCEON MO79 oil- MO,AB,POE or Suva R-404A oil- POE , Suva R-408A oil-AB,MO, Suva R-507, oil-POE Suva HP-80 oil-AB,MO. Have a Suva day.:rolleyes:

[refrigman22]

I agree R-408 is a great replacement as well. Just look at price of the gas and what you see more of........It's tough to have a Baskin Robins in your truck "31 flavors" just a thought.

[k-fridge]

R-408 is probably the easiest replacement. The manufacturer says it's OK with mineral oil, but I still think it's best to change part of it out with AB. Or...you could do a complete oil change to POE, which works well with 408, and down the road a ways you could do one more oil change and you'd be good for 404.

HP-80 is also a fine replacement for 502 low temp, use AB oil for that one.

The best long term solution might be 404. Go with all POE oil, you might need to change it twice to get the original oil content down below the recommended 5%. Change the dryer and pull a hard vacuum. POE has a tendency to dissolve all the built up crud in the system so I'd plan on going back in a day or two and changing the dryers again.

With either refrigerant, check the superheat when near temp. None of the replacement refrigerants are actual drop ins so you'll likely need to make some minor adjustments. Typically with 408 the TXV will need to be closed off a bit.

Edited to fix my screw ups...

[rimek]

We had a tandem system with 7.5 hp pumps that had compressor failures at 2 different times, so we were retrofitting with a -10°F evaporator(couldn't shut down whole unit). We chose HP-80 and zerol 200TD oil, and one was done in 1993 and the other done in 1995, with absolutely no troubles as of today. Box is a 40' X 15' X 7' meat storage.

[just_opinion]

if you are to conver the freon of the system that has mineral oil, try to use AB oil. It is more forgiven then POE oil.

Yes, it is true that 404A and 134a are the long term freon. But

If the system uses mineral oil, it is old and near the end of its life. Don't put any more stress on the machine and especially more headache on you.

[icemeister]

....Or...you could do a complete oil change to POE, which works well with 409...

I think you meant to say 408.


MP-39 is also a fine replacement for 502 low temp, use AB oil for that one.That should be MP-80 (R402A).

Bad day, Ken? ;)

[k-fridge]

I think you meant to say 408.

That should be MP-80 (R402A).

Bad day, Ken? ;)
Jeez, that's what I get for posting in a rush. Thanks for catching me on those.

[shaun66]

i wouldnt recommend HP80 as a replacement, - to many high head calls in summer, used HP80 in early 90's , now always use 404 or 507

[270wsm]

ISCEON MO79 (422A) is the best long term 502 replacement. No need to change to POE oil like with some of the others. We have a couple racks running this stuff for over a year with no problems.

[the mojo]

ISCEON MO79 (422A) is the best long term 502 replacement. No need to change to POE oil like with some of the others. We have a couple racks running this stuff for over a year with no problems.

;) And thats why I posted at the beginning of choices.;)

[refrigman22]

422a- Wal-Mart is going to use hell out of that gas! They have started already. Good stuff but $$$$$$$$$$$$$$$$$$$$$$$$$

[the mojo]

422a- Wal-Mart is going to use hell out of that gas! They have started already. Good stuff but $$$$$$$$$$$$$$$$$$$$$$$$$

But remember.... Wallymart has d...e...e...p pockets.:rolleyes: Hey is there an echo in here.:D

[Airmechanical]

delete

[Airmechanical]

i wouldnt recommend HP80 as a replacement, - to many high head calls in summer, used HP80 in early 90's , now always use 404 or 507

hp80 works well if you have a cooling fan over the heads! :cool:



.

[just_opinion]

hp80 works well if you have a cooling fan over the heads! :cool:



.

I thought HP80 run at lower discharged temperature than R502. In fact it runs at 5 degrees lower. It also gives 10% more capacity.

Even though its discharge pressure is higher than R502. In fact 40 PSIG higher.
Even though its suction pressure is higher than R502. In fact 5 PSIG higher

So higher pressure does not mean bad at all.

It is the discharge temp (from compression so called the "adiabetic") is worrying us and the equipment

[300 Win Mag]

I use the 422A.

[freezerfixer]

i normally use 408a without any problems, but i think it is also getting pretty expensive. if you have the time and resources to change oil to POE i would say that 404a would be my choice of replacement. around here, 404a has become real popular.
only bad thing is that POE oil will clean the system and you might as well plan on going back and cleaning the TXV screens and replacing the drier cores.
if it is a rack with an oil separator, the bottom plate assembly and inlet screen may have to be cleaned. i would also add a sporlan OF-303-T (oil filter) in the feed line. i have become a firm believer in those things.;)

[arthurpaul]

I have herd a lot about HP80. I use it only on the old Manitowoc ice machines that use HP81. That dag-on HP81 in its 14# can is an expensive pain in the ear. I have found HP80 works well for this. The discharge temp. of HP80 is a little lower than HP81 but it doesn't make a noticable difference in the defrost time....

Art.:)

[hvacman77]

507 is great but it is a short term replacement for 502. I like it because if you look at the p.t. chart it is very close to that fantastic no longer in production, 502. My experience in 507 has been in supermarket racks, which have been converted in the 90's to now. 404a is long term, in new installations to retro fits small walk-ins and up. Either way it's P.O.E. OIL CHANGE NECESSARY. so long term-or short term?

[Andy Schoen]

Perhaps the pedigree of R-422 refrigerant blends might be of interest here. R-422 is a blend of R-125, R-134a, and R-600a (isopropane).

R-422A: originally Rhodia ISCEON 79, marketed by ICOR International as One Shot, acquired by DuPont Aug 2005 and now designated ISCEON MO79. Composition by weight: R-125 85.1%, R-134a 11.5%, and R-600a 3.4%. Primarily an R-502 replacement.

R-422B developed and marketed by ICOR International as NU22. Composition by weight: R-125 55%, R-134a 42%, and R-600a 3%. Primarily an R-22 replacement.

R-422C developed and marketed by ICOR International. Composition by weight: R-125 82%, R-134a 15%, and R-600a 3%. Primarily an R-502 replacement.

R-422D: originally Rhodia ISCEON 29, acquired by DuPont Aug 2005 and now designated ISCEON MO29. Composition by weight: R-125 65.1%, R-134a 31.5%, and R-600a 3.4%. Primarily an R-22 replacement.

[arthurpaul]

Hay guys, please give me a break....There are soooo many refrigerants on the market today that I need a score card to keep track of them. I'm just an old guy. I have a hard time remembering my wife's name. When I had my refrigeration Co. in South Fla. I had so many different color tanks in my truck
it just dove me nuts.

I thought the business was for 134a,404a and 410a. I try to keep is simple. For r12 I use Hot Shot.

This is what happens to old old refrigeration men....

Tx Art

[refrigman22]

Bahh!!!! Sell them a new system!!!!!!! DONE!!:D

[crackertech]

although not low temp I finely converted a med temp rack to hp 80 from
502 everything went pretty smooth.replaced a couple of power heads.
and twicked superheat.and reset sorits.of course we changed oil and
drier cores.cleaned sump screens sentronic sensors ect.all in all things are
working great.