Section 7 | Refrigeration System |
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HFC REFRIGERANT QUESTIONS AND ANSWERS
Manitowoc ice machines use
1.What compressor oil does Manitowoc require for use with HFC refrigerants?
Manitowoc products use Polyol Ester (POE) type compressor oil. It is the lubricant of choice among compressor manufacturers.
2.What are some of the characteristics of POE oils?
They are hygroscopic, which means they have the ability to absorb moisture. POE oils are 100 times more hygroscopic than mineral oils. Once moisture is absorbed into the oil, it is difficult to remove, even with heat and vacuum. POE oils are also excellent solvents, and tend to “solvent clean” everything inside the system, depositing material where it is not wanted.
3.What do these POE oil characteristics mean to me?
You must be more exacting in your procedures. Take utmost care to prevent moisture from entering the refrigeration system. Refrigeration systems and compressors should not be left open to the atmosphere for more than 15 minutes. Keep oil containers and compressors capped at all times to minimize moisture entry. Before removing the system charge to replace a faulty component, be sure you have all of the needed components at the site. Remove new system component plugs and caps just prior to brazing. Be prepared to connect a vacuum pump immediately after brazing.
4.Are there any special procedures required if a POE system is diagnosed with a refrigerant leak?
For systems found with positive refrigerant system pressure, no special procedures are required.
For systems found without any positive refrigerant pressure, assume that moisture has entered the POE oil. After the leak is found and repaired, the compressor oil must be changed. The compressor must be removed and at least 95% of the oil drained from the suction port of the compressor. Use a “measuring cup” to replace the old oil with exactly the same amount of new POE oil, such as Mobil EAL22A.
Remember, care must be taken to prevent moisture from getting into the refrigeration system during refrigeration repairs.
5.How do I
Use equipment designed for HFC detection. Do not use equipment designed for CFC detection. Consult leak detection equipment manufacturers for their recommendations. Also, standard soap bubbles will work with HFC refrigerants.
6.Does Manitowoc use a special liquid line
Yes. Manitowoc uses an ALCO “UK” series filter- drier for increased filtration and moisture removal. During a repair, Manitowoc recommends installing the drier just before hooking up a vacuum pump.
7.Is other special equipment required to service HFC refrigerants?
No. Standard refrigeration equipment such as gauges, hoses, recovery systems, vacuum pumps, etc., are generally compatible with HFC refrigerants. Consult your equipment manufacturer for specific recommendations for converting existing equipment to HFC usage. Once designated (and calibrated, if needed) for HFC use, this equipment should be used specifically with HFC refrigerants only.
8.Do I have to recover HFC refrigerants?
Yes. Like other refrigerants, government regulations require recovering HFC refrigerants.
9.Will
No. Like
10.How do I charge a system with HFC refrigerant?
The same as
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