Search results
Results from the WOW.Com Content Network
HP80 and MP39 replacements. We've used MP39 since the R-12 phaseout, same with HP80. Both work very well, with any oil in short coupled applications. 134A has been nothing but a nuisance with it's low capacity, and my habit has been to remove the 134A and replace it with MP39 when I do repairs on small equipment.
Just charge to full sight glass like normal and watch your superheat. I have personally converted a handful of r12 walk-ins to 134a. Pull down time from 70*F was marginally slower (at least in my head) but no problems maintaining. Your TXV will be slightly over sized with 134a so you may need to make a txv adjustment.
once again mp39/401a is the perfect drop in for r-12. kitten, pressures were 38/190 cooler temp was 38 degrees at completion! this post is just another thumbs up for this drop in refrigerant! No doubt, MP-39 is one of the best replacements for R-12 in medium temp applications.
This from ASHRE " MP39 has a slightly higher discharge temperature than R12, 409A has a significantly higher discharge temperature then R12 so caution must be used! [Edited by icehouse on 02-24-2005 at 04:14 PM] RAM Teaching Tomorrows Technicians Today. Reply.
MP39 vs hotshot (here we go again) Worked on an old R12 reach in other day. Med temp min oil. Fixed leak opted to use MP-39 instead of hot shot. Recall an old timer who told me he didnt like using hot shot. Other then hot shot seems to run slightly lower pressures at slightly higher pressures cant see any benefit.
Forum Rules. I'm looking at a 4x4x8 walk in cooler. was a r12 now mp39. this unit has been thrown together nothing fancy. what type of pressures, sh, sc and td should this unit be running. one thing i did noticed that it didn't have a solinoid valve or low pressure switch for pump down. shouldn't this have one? i noticed floodback on startup ...
all the R12 subs have about the same miscibility with Mineral oil. For example HotShot and MP39 have almost the same miscibilty with Mineral Oil yet HotShot claims "no oil change". Alka Benzyne offers better miscibility than Mineral oil with which is why Cope,Carlye and Tecumseh say change the oil.
MP39 is a replacement refrigerant for R12 and so it runs similar to R134A. I wonder if somebody installed it and found it was too much capacity with R22 and switched to MP39? But then, why MP39 when R134A would have been a better choice and a lot cheaper?
mp39 walk in cooler with water cooled cond. Went on a call for unit shutting down, and in the customer's words "no water coming out of the drain line" of a pump-and-dump, water-cooled condenser. WRV was sticking, so I backed off the spring a bit and it opened. Now he's happy because there's water dumping, but I digress.
I have seen mp-39 in med temp systems quite frequently, and have used mp-39 as a retrofit on old r-12 reach ins, with out having to change the oil, with Great success. I've also used it in supermarket refrigeration, however have changed the oil to ab200. Must be a typo they mean poe. Using mo is a gamble.