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will energize the economizer; a second-stage
demand will energize compressor 1.
3- Ultra high efficiency units have a tandem refrigerant
ciruit. High and standard efficiency units have two
typical circuits. See figure 24, 25, or 26.
4- Each refrigerant circuit is charged with R410A
refrigerant. See unit rating plate for correct
amount of charge.
5- Refer to Cooling Operation and Adjustment section for
proper method to check refrigerant charge.
C-R410A Refrigerant
Units charged with R410A refrigerant operate at much
higher pressures than R22. The expansion valve and
liquid line drier provided with the unit are approved for use
with R410A. Do not replace them with components
designed for use with R22.
R410A refrigerant is stored in a pink cylinder.
Manifold gauge sets used with systems charged with
R410A refrigerant must be capable of handling the higher
system operating pressures. The gauges should be rated
for use with pressures of 0-800 on the high side and a low
side of 30” vacuum to 250 psi with dampened speed to
500 psi. Gauge hoses must be rated for use at up to 800
psi of pressure with a 4000 psi burst rating.
FIGURE 24
REFRIGERANT STAGES - 092H, 102H, 120H, 150S
ALL-ALUMINUM COIL
1
2
(BOTH FANS ARE ENERGIZED
WITH A Y1 DEMAND)
EVAPORATOR
COIL STAGE 1
EVAPORATOR
COIL STAGE 2
CONDENSER
COIL STAGE 2
CONDENSER
COIL STAGE 1
CONDENSER
FAN STAGE 1
CONDENSER
FAN STAGE 2
B4
B5
IMPORTANT
Mineral oils are not compatible with R410A. If oil
must be added, it must be a polyol ester oil.
FIGURE 25
REFRIGERANT STAGES - 092H, 102H, 120H, 150S
TRADITIONAL FIN/TUBE COIL
1
2
(BOTH FANS ARE ENERGIZED
WITH A Y1 DEMAND)
EVAPORATOR
COIL STAGE 2
CONDENSER
FAN STAGE 1
CONDENSER
FAN STAGE 2
B4
B5
EVAPORATOR
COIL STAGE 1
FIGURE 26
1
2
(ALL FANS ARE ENERGIZED IN LOW SPEED WITH A Y1
DEMAND AND HIGH SPEED WITH A Y2 DEMAND)
EVAPORATOR
COIL
OUTDOOR
COIL
OUTDOOR
FAN 1
OUTDOOR
FAN 2
B5
REFRIGERANT STAGES - 094U, 122U, 152U
TRADITIONAL FIN/TUBE COIL
B4
OUTDOOR
FAN 3
B21
