66433-YIM-B-1004
Unitary Products Group 23
TYPICAL WIRING DIAGRAM NOTES (SEE FIGURES
13, 14, AND 15)
1. All field wiring to be accomplished following city, local
and/or national codes in effect at time of installation of
this unit.
2. Motors are inherently protected.
3. See unit nameplate for maximum fuse size and minimum
circuit ampacity.
4. Select indoor blower cooling speed from the Unit Wiring
Diagram Table 1. Heating speed is preset at the factory.
5. If ASCT is present, wire 226/BL and 229/BL are con-
nected to ASCT-3. If LR only is present, wire 226/BL and
229/BL are connected to M1 coil and wire 807/BL is
omitted.
For further reference see R-410A Technical Training literature P/N 036-60905-001-B-0502.
Label all wires prior to disconnection when servic-
ing controls. Wiring errors can cause improper and
dangerous operation if any of the wire as supplied
with this unit must be removed it must be replaced
with type 105°C, 600V wire or equivalent clearly
renumbered for identification. Verify proper opera-
tion after servicing.
Open all disconnects before servicing this unit.
FIGURE 16 - R-410A QUICK REFERENCE GUIDE
R-410A QUICK REFERENCE GUIDE
Refer to Installation Instructions for specific installation requirements.
R-410A Refrigerant operates at 50 - 70 percent 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.
Recovery equipment must be rated for R-410A.
Do Not use R-410A service equipment on R-22 systems. All hoses, gages, recovery cylinders, charging
cylinders and recovery equipment must be dedicated for use on R-410A systems only.
Manifold sets must be at least 700 psig high side, and 180 psig low side, with 550 psig retard.
All hoses must have a service pressure rating of 800 psig.
Leak detectors must be designed to detect HFC refrigerants.
Systems must be charged with liquid refrigerant. Use a commercial type metering device in the
manifold hose.
R-410A can only be used with POE type oils.
POE type oils rapidly absorb moisture from the atmosphere.
Vacuum pumps will not remove moisture from POE type oils.
Do not use liquid line driers with a rated working pressure rating less than 600 psig.
Do not install suction line driers in the liquid line.
A liquid line drier is required on every unit.
Do not use a R-22 TXV. If a TXV is to be used, it must be a R-410A TXV.
Never open system to atmosphere when under a vacuum.
If system must be opened for service, evacuate system then break the vacuum with dry nitrogen and
replace all filter driers.
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