TECHNICAL SUPPORT MANUAL Split System Heat Pump: N4H3
428 04 510201 3
R--410A QUICK REFERENCE GUIDE
• R--410A refrigerant operates at 50% -- 70% higher pressures than R--22. Be sure that servicing equipment and
replacement components are designed to operate with R--410A.
• R--410A refrigerant cylinders are rose colored.
• Recovery cylinder service pressure rating must be 400 psig, DOT 4BA400 or DOT BW400.
• 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.
• Manifold sets should be 750 psig high--side and 200 psig low--side with 520 psig low--side retard.
• Use hoses with 750 psig service pressure rating.
• Leak detectors should be designed to detect HFC refrigerant.
• R--410A, as with other HFC refrigerants, is only compatible with POE oils.
• Vacuum pumps will not remove moisture from oil.
• Do not use liquid line filter--driers with rated working pressures less than 600 psig.
• Do not install a suction line filter--drier in liquid line.
• POE oils absorb moisture rapidly. Do not expose oil to atmosphere.
• POE oils may cause damage to certain plastics and roofing materials.
• Wrap all filter--driers and service valves with wet cloth when brazing.
• A liquid line filter--drier is required on every unit.
• Do not use with an R--22 TXV.
• If indoor unit is equipped with an R--22 TXV, it must be changed to an R--410A TXV.
• Never open system to atmosphere while it is under a vacuum.
• When system must be opened for service, break vacuum with dry nitrogen and replace all filter--driers. Evacuate
to 500 microns before recharging.
• Do not vent R--410A into the atmosphere.
• Do not use capillary tube indoor coils.
• Observe all WARNINGS, CAUTIONS, NOTES, and bold text.
International Comfort Products, LLC
Lewisburg, TN 37091 USA