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