R 404a

[suny]

Hi everybody who participated in this thread,

My technician told me today that there is refrigeration oil in the market with brand name “PAG” which can be used on system that ran on mineral oil. There is no injury to the system if we charge the R 404a compressor in my case Manuerop with PAG oil instead of ester oil. Please give your opinion.

Suny

[TXiceman]

The PAG is a poly alkyl glycol based oil and the ester oil is a POE.

Best to check wit the compressor manufacturer to see which oil type he recommends for the compressor. One point in particular is to watch the elastomers in the system. Wrong oil and the elastomers will swell and then fail.

Last point is DO NOT mix oils. In order to change the oil, you should drain all of the oil from all low points. next charge with a fresh charge of oil and operate for 48 hours and dump this oil charge. Recharge with fresh oil and run for 48 hours. Take an oil sample and have it checked by a lab for contamination from the old oil.

Some times it make take 3 or more oil changes to get all of the old oil out.

I had a fellow put the wrong synthetic oil in an ammonia system and you would not believe the mess. He just changed the oil in the crankcase and when he had a compressor start knocking (Mycom recip). When we opened it for inspeciton, there were globs of a rubbery stugg in the crankcase and he had wiped the rod bearings.

After the rebuild, we flushed the oil system 3 times before we were satisfied the oil was OK. In this case we went back to a straight mineral based oil.

Then the fun started, trying to collect on the bill. We did the work on an open time and material order with an estimated cost up front. We were right on estimated cost.

Ken

Ken

[Samarjit Sen]

Hi Suny,

As Ken said, please do not mix oil. Moreover it is always better to ask the compressor manufacturer. Lonmg time back I had a lot of problem, as one of my clients of his own added a wrong oil and the entire system just got chocked up. It was a hell of a job cleaning up the system.

[suny]

Thank you both Ken & Samarjit for you advice and the seriousness of oil getting mixed in the system. Even at any cost I am going to flush out the mineral oil left in the system.

Furthermore for your information herewith I am attaching the comments made by the manufacturer’s representative. I Quote:

“The LTZ compressor is not suitable for R22 even after oil change. Basically, we had to discontinue the CFC/HCFC range for low temperature application long back in the late 90s, due to new regulations worldwide on the (limitations on) usage of CFC and HCFC.

After dis-mantling the compressor, you could flush the existing system with R141b or any solvent (unleaded petrol could be a good choice - but, please maintain safety). Please do not use CTC solution as it has chloride content although it is a good solvent. Solvent will clean the system of all traces of any mineral oil leftover from the previous installation. Then, you could use the LTZ88 with R404A or R507.

I hope you have correctly selected the LTZ88 to replace Bitzer open type. In case, you do the above, please remember to change the Filter Drier and Expansion valve suitably”.

[The MG Pony]

Isopropyle alcohol all so makes a very nice cleaning agent!

[suny]

Hi MG Pony!

Thank you very much for your suggestion to use Isopropyl Alcohol. In general terms here we call for Isopropyl Alcohol as Surgical Sprit. How about, if I use Methyl Alcohol as cleaning and flushing agent. Please give your advice.

Suny

[Samarjit Sen]

Hi Suny,

Why are replacing the Bitzer open type with Maneurop LTZ compressor. What is the temperature required for the Evaporation and the Condensing ? Did you have any problem with Bitzer open type compressor. Could you please give me some details as I would like to do a bit of study on the same.

[suny]

Hi Dear Samarjit

I am sorry u have misunderstood, that I am going to replace a Bitzer with Manuerop. The system I am going to install ran with a Bitzer open comp on R22. I used t Bitzer for a mobile truck. The Manuerop I had as a spare comp which I am going to utilize for t ice cream storing room with a temp of -30 deg C. If u need any info about t freezer truck I could give details. Further all my replacments are done either with Bitzer or Manuerop.

Suny

[Samarjit Sen]

Suny how are you. Do you think Maneorop sealed compressor would be able to attain the temperature of - 30oC for the Ice Cream Room.

A semi hermetic of Bitzer or Dorin with Vapour injection would have been more suitable. You would be requiring a Te of about - 35oC.

I shall definately seek your assistance for the truck refrigeration system.

With all my best wishes,

[suny]

Dear Samarjit

Yes, I am using Manuerop compressors to maintain a cut out temperature of -30 deg C in my cold rooms. It is the LTZ series with R 404a. Even the manufacturers recommend that we can go up to - 40 deg C Te. They have introduced another series NTZ a multi refrigerant compressor. I have not used it yet. There is another advantage the prices are cheaper than the semis.

Suny