Manitowoc Marine Q 1800 Service Manual

Also see for Marine Q 1000: Use and care manual Installation instructions Service technician's handbook

Contents

54Refrigeration System Section 7HFC REFRIGERANT QUESTIONS AND ANSWERSManitowoc uses R-404A and R-134A HFCrefrigerants with ozone depletion potential (ODP)factors of zero (0.0). R-404A is used in icemachines and reach-in freezers and R-134A isused in reach-in refrigerators.1. What compressor oil does Manitowoc requirefor use with HFC refrigerants?Manitowoc products use Polyol Ester (POE)type compressor oil. It is the lubricant ofchoice among compressor manufacturers.2. What are some of the characteristics of POEoils?They are hygroscopic, which means they havethe ability to absorb moisture. POE oils are100 times more hygroscopic than mineral oils.Once moisture is absorbed into the oil, it isdifficult to remove, even with heat andvacuum. POE oils are also excellent solvents,and tend to “solvent clean” everything insidethe system, depositing material where it is notwanted.3. What do these POE oil characteristics mean tome?You must be more exacting in yourprocedures. Take utmost care to preventmoisture from entering the refrigerationsystem. Refrigeration systems andcompressors should not be left open to theatmosphere for more than 15 minutes. Keep oilcontainers and compressors capped at all timesto minimize moisture entry. Before removingthe system charge to replace a faultycomponent, be sure you have all of the neededcomponents at the site. Remove new systemcomponent plugs and caps just prior tobrazing. Be prepared to connect a vacuumpump immediately after brazing.4. Are there any special procedures required if aPOE system is diagnosed with a refrigerantleak?For systems found with positive refrigerantsystem pressure, no special procedures arerequired.For systems found without any positiverefrigerant pressure, assume that moisture hasentered the POE oil. After the leak is foundand repaired, the compressor oil must bechanged. The compressor must be removedand at least 95% of the oil drained from thesuction port of the compressor. Use a“measuring cup” to replace the old oil withexactly the same amount of new POE oil, suchas Mobil EAL22A.Remember, care must be taken to preventmoisture from getting into the refrigerationsystem during refrigeration repairs.5. How do I leak-check a system containing HFCrefrigerant?Use equipment designed for HFC detection.Do not use equipment designed for CFCdetection. Consult leak detection equipmentmanufacturers for their recommendations.Also, standard soap bubbles will work withHFC refrigerants.6. Does Manitowoc use a special liquid linefilter-drier with HFC refrigerants?Yes. Manitowoc uses an ALCO “UK” seriesfilter-drier for increased filtration and moistureremoval. During a repair, Manitowocrecommends installing the drier just beforehooking up a vacuum pump.Continued on next page...