R-402b for ice machine??

[55fordtruck]

Working on a ice machine with R-12. CC Dickson co. told me that R-402b was recomended by the manufacture for replacement. Anyone used this stuff?? I noticed that it has propane in it. Thought that wasn't good. And as for charging a unit with a blend do you just charge it as a liguid on the low pressure side? Thanks for all the help. Kevin




Sorry I meant R-402a instead of b. There are way too many diff. kinds out there.

[Edited by 55fordtruck on 04-29-2004 at 09:07 PM]

[condenseddave]

WAS the recommended replacement for 502 in Manitowoc ice machines, when they came out with their "B" series, which was the only mass-produced piece of equipment that used this crap-in-a-can.

It is not even close to R12 on the PT chart, and is expensive as all gitout.

I would go with 134a, or, if you're so inclined, 401B, aka "MP66", which is an HCFC replacement for low temp R12.

My first choice is definitely 134a.

Well, actually, my first choice with an R12 ice machine, would be recover, tag, and dispose. Then replace with something new, anything new. Well, anything new EXCEPT a Cornelius.

[cynic]

manitowic used it for a couple of years(hp81), yes it needs to be charged as a liquid however is the machine worth it ? daves right its way closer to 502 than 12

[ziggy24]

402B is still used by manitowac ive had pretty good luck with it. You can buy it in a small can of like 14lbs i think it is. Has to be charged as a liquid but you should be able to weigh it in through the high side from a vacuum. Just weigh in 80% of what the unit took for R-12 then run the unit. It should only take about 12-17 mins to make a batch of ice so start checking superheat @ the compressor around 8-10mins into the cycle. Adjust the charge as needed, should be around 10-12F superheat @ the compressor just before going into harvest. Assuming everythings clean and the space its in is with normal operating temps.

Good Luck
Bill

[condenseddave]

Which currently produced machine is manitowoc useing HP81 in?

You can buy it wholesale in 13 lb. cans. It's going for about 15 bucks a pund, though.

Why would ANYONE want to retrofit TO this expensive crap-in-a-can?

[55fordtruck]

Here's what I found out with more research. Manitowoc recomends for the R-12 machine (ED0402A) that I'm working on that I need to replace the TXV for MP39(401A), dump the oil out of the compressor and replace with Alkylbenzene oil. Then add the proper amount ou MP39. The machine that I'm working on holds 22oz. of R-12. Manitowoc's chart says to put 15oz of MP39 in. The head pressure will be 5-35#'s higher and low side 3-5#'s higher. Hope this helps anyone in the future. Also as for the R402b that is to replace R-502 machine's. Thanks for the help. KEVIN

[condenseddave]

408 is a better bet for any 502 icemaker.

Manitowoc is still indignant that the industry didn't fall in line behind them and make HP81 the chosen refrigerant for 502 ice machine retrofits. Too bad.

408 and 502 are near identical throughout the entire PT chart.

HP81 isn't anywhere near the refrigerant that 408 and 404 are are, plus, you can expect a serious increase in discharge temperature with 81, which you won't see with 408.

MP 39 might work fine in an R12 icemaker, but I'd be more inclined to change to MP66, IF I found an R12 Manitowoc that still had an evaporator that wasn't shot, and that is a rare find.

[ziggy24]

No machine is currently being produced with 402b, but Manitowoc did produce machines with 402b i think this was in the late 90s have to check to be sure but I have 2 or 3 still running with 402b, trouble free.

Ive also used as a 502 replacement but this was in a case where we were running a box temp at like -30 in a enviromental chamber.

Wasnt a fun changeover though being 402b requires oil change

Bill

[hfrefrigeration]

I have used 414-B in R-12 ice machines with good results. It also goes under the name hot shot. Did not have to change oil or anything.

[icemeister]

Manitowoc used HP81 only for their "B-Series" machines which were produced around 1993-95. They then went to the "J-Series" which used R-404A and on to the "Q" and now "S" machines.

The big deal about HP 81 was as Dave mentioned is the higher discharge temperatures and Manitowoc wanted to see 170+ Deg F during the freeze cycle to buildup enough heat in the system for a proper harvest. I experimented recently with an old "B-600" using HP81 and then switching to HP 80. The HP81 discharge temps were generally 20 Deg F higher than the HP80 and the harvest time with HP 81 was 1.5 minutes vs almost 2.5 minutes with the HP80. Interestingly enough, the HP81 ran a lower evaporator SH but resulted in a higher compressor discharge temperature.

My overall opinion is that it was probably easier to get Dupont to manufacture a special refrigerant than to engineer a machine that actually worked well on the generally accepted R502 replacement refrigerant.

As far as the old R12 machines goes, R401A (MP39) was in fact Manitowoc's designated interim replacement refrigerant and I recall having to swap TXVs on the 400s (it was actually adjustable). I don't remember them requiring an oil change even back when Dupont said it was necessary.

[bzzline]

If you are going to change the txv might as well change it to r-22 the freon works well in ice machines and you can probly find a old a/c compressor cheaper than getting freon that you will not ever use.

[bzzline]

If the compressor has already been swaped it may work with R-22 alot of retros were doing this.

[asibari]

I used 401-a in a manotowoc ice machine. It was recommended because we couldn't get the original compressor that used r-12. Anyway since I made the changeover I have rebuilt all of our ice machines and recharged with hot shot. (414-b) They all work fine.