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APPENDIX A
Air Conditioner & Heat Pump with R- -410A
— Quick Reference Guide
S R-410A refrigerant operates at 50 percent to 70 percent
higher pressures than R-22. Be sure that servicing
equipment and replacement components are designed to
operate with R- - 410A.
S R- - 410A refrigerant cylinders are rose colored.
S Recovery cylinder service pressure rating must be 400
psig, DOT 4BA400 or DOT BW400.
S R- - 410A systems should be charged with liquid
refrigerant. Use a commercial type metering device in
the manifold hose when charging into suction line with
compressor operating.
S Manifold sets should be 700 psig high side and 180 psig
low side with 550 psig low-side retard.
S Use hoses with 700 psig service pressure rating.
S Leak detectors should be designed to detect HFC
refrigerant.
S R- - 410A, as with other HFCs, is only compatible with
POE oils.
S Vacuum pumps will not remove moisture from oil.
S Use only factory specified liquid-line filter driers with
rated working pressures greater 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 factory approved, liquid-line filter drier is required on
every unit.
S Do not use an R-22 TXV.
S If indoor unit is equipped with a TXV, it must be
changed to a R- - 410A TXV.
S Never open system to atmosphere while it is under a
vacuum.
S When system must be opened for service, recover
refrigerant, break vacuum with dry nitrogen before
opening system.
S Always replace filter drier after opening system for
service.
S Do not vent R- - 410A into the atmosphere.
S Do not use capillary tube coils.
S Observe all warnings, cautions, and bold text.
S All R- - 410A heat pumps must have indoor TXV.
S Do not leave R- - 410A suction line driers in place for
more than 72 hours.
501 01 3600 01
Unit
CAS090*G/H
Low Ambient Option — Factory Installed
CAS090*H units with the factory installed low ambient
option are equipped with a Motormaster
pressure control which regulates fan speed. A temperature
sensor mounted on the outdoor coil controls the speed of
approved outdoor fan motors in order to maintain a
constant head pressure in the outdoor coil (see Fig. 26).
The control maintains the appropriate head pressure at
low ambient temperatures down to - - 20_F (- - 28_C).
Fig. 26 - - CAS090*H Motormaster Sensor Location
Specifications are subject to change without notice.
APPENDIX B
Wiring Diagram List
Electrical
Characteristics
208/230---3---60
38AU000026
460---3---60
38AU000027
575---3---60
38AU000025
APPENDIX C
R
solid- - state head
Diagram
Number
C14297
29
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