Carrier 50CR - Manual (Page 29)

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HEAT PUMP WITH PURON
REFRIGERATION SECTION QUICK--REFERENCE GUIDE
Puron refrigerant operates at 50--70 percent higher pressures than R--22. Be sure that servicing equipment and replacement components are
designed to operate with Puron. Puron refrigerant cylinders are rose colored.
S Puron refrigerant cylinders manufactured prior to March 1, 1999, have a dip tube that allows liquid to flow out of cylinder in
upright position. Cylinders manufactured March 1, 1999 and later DO NOT have a dip tube and MUST be positioned upside down
to allow liquid to flow.
S Recovery cylinder service pressure rating must be 400 psig. DOT 4BA400 or DOT BW400.
S Puron systems should be charged with liquid refrigerant. Use a commercial--type metering device in the manifold hose.
S Manifold sets should be 750 psig high side and 200 psig low side with 520 psig low side retard.
S Use hoses with 750 psig service pressure rating.
S Leak detectors should be designed to detect HFC refrigerant.
S Puron, as with other HFCs, is only compatible with POE oils.
S Vacuum pumps will not remove moisture from oil.
S Only use factory--specified liquid--line filter driers with rated working pressures no less than 600 psig.
S Do not install a suction--line filter drier in liquid line.
S POE oils absorb moisture rapidly. Do not expose oil to atmosphere.
S POE oils may cause damage to certain plastics and roofing materials.
S Wrap all filter driers and service valves with wet cloth when brazing.
S A Puron liquid--line filter drier is required on every unit.
S Do not use an R--22 TXV.
S Never open system to atmosphere while it is under a vacuum.
S When system must be opened for service, break vacuum with dry nitrogen and replace filter driers.
S Do not vent Puron into the atmosphere.
S Observe all warnings, cautions, and bold text.
S Do not leave Puron suction line driers in place for more than 72 hrs.
50C
R