XVI. R-410A REFRIGERANT
A. TOOLS REQUIRED FOR INSTALLING & SERVICING R-410A MODELS
Manifold Sets:
-Up to 800 PSIG High Side
-Up to 250 PSIG Low Side
-550 PSIG Low Side Retard
Manifold Hoses:
-Service Pressure Rating of 800 PSIG
Recovery Cylinders:
-400 PSIG Pressure Rating
-Dept. of Transportation 4BA400 or 4BW400
!CAUTION
R-410A systems operate at higher pressures than R-22 systems. Do not use R-22 service equipment or components on R-410A equipment.
B. SPECIFICATION OF R-410A:
Application: R-410A is not a drop-in replacement for R-22; equipment designs must accommodate its higher pressures It cannot be retrofitted into R-22 condensing units.
Physical Properties: R-410A has an atmospheric boiling point of -62.9°F and its satu- ration pressure at 77°F is 224.5 psig.
Composition: R-410A is an azeotropic mixture of 50% by weight difluoromethane (HFC-32) and 50% by weight pentafluoroethane (HFC-125).
Pressure: The pressure of R-410A is approximately 60% (1.6 times) greater than R-22. Recovery and recycle equipment, pumps, hoses and the like need to have design pres- sure ratings appropriate for R-410A. Manifold sets need to range up to 800 psig high- side and 250 psig low-side with a 550 psig low-side retard. Hoses need to have a ser- vice pressure rating of 800 psig. Recovery cylinders need to have a 400 psig service pressure rating. DOT 4BA400 or DOT 4BW400.
Combustibility: At pressures above 1 atmosphere, mixture of R-410A and air can become combustible. R-410A and air should never be mixed in tanks or supply lines, or be allowed to accumulate in storage tanks. Leak checking should never be done with a mixture of R-410A and air. Leak checking can be performed safely with nitrogen or a mixture of R-410A and nitrogen.
C. QUICK REFERENCE GUIDE FOR R-410A
•R-410A refrigerant operates at approximately 60% higher pressure (1.6 times) than R-22. Ensure that servicing equipment is designed to operate with R-410A.
•R-410A refrigerant cylinders are pink in color.
•R-410A, as with other HFC’s, is only compatible with POE oils.
•Vacuum pumps will not remove moisture from oil.
•R-410A systems are to be charged with liquid refrigerants. Prior to March 1999, R-410A refrigerant cylinders had a dip tube. These cylinders should be kept upright for equipment charging. Post March 1999 cylinders do not have a dip tube and should be inverted to ensure liquid charging of the equipment.
•Do not install a suction line filter drier in the liquid line.
•A liquid line filter drier is standard with every unit. Only manufacturer approved liquid line filter driers can be used. These filter driers are rated for minimum working pres- sure of 600 psig.
•Desiccant (drying agent) must be compatible for POE oils and R-410A.
