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5.0 SYSTEM START-UP AND REFRIGERANT CHARGING
Start-Up
5.7 Indoor Air-Flow
Verification
Correct indoor air-flow and proper supply air
distribution is critical to system comfort, efficiency
and reliability. Excessive indoor air-flow results in
elevated humidity levels in the cooling mode and
excessive air noise. Low indoor air-flow reduces
system capacity and can result in coil icing and
compressor failure in the cooling mode and can
cause nuisance high pressure switch tripping
and increases power consumption in the heating
mode.
Fortunately, when the (-)A15AZ/(-)P16AZ/(-)A16AZ
outdoor unit are matched to the correct air-handler
or furnace/coil combination and are controlled by
the communication EcoNet
TM
Control Center, the
indoor air-flow is automatically controlled to the
proper level based on the model data stored in the
VSODC. When the indoor blower is operating, the
EcoNet
TM
Control Center will display the indoor
air-flow in the Service Menu of the control. The
approximate indoor air-flow is also displayed in
100 CFM [47 l/s] increments by a flashing LED on
the air-handler or furnace control board while the
blower is operating (one flash per 100 CFM [47
l/s]) for installations where a conventional 24VAC
thermostat is used.
Once the system is operating in the Charging
Mode, confirm the indoor air-flow is close to those
values in the table below. If the displayed indoor
air-flow is not reasonably close to the value in the
table, confirm cooling dehumidification is disabled,
the indoor air-flow trim adjustment is set to 0%,
and verify the model numbers of the indoor and
outdoor units are an approved combination by
the manufacturer. Once the indoor air-flow is
verified, the indoor air-flow trim adjustment may
be changed to suit the installation and should be
done prior to final charge adjustment.
NOTICE: AHRI rated indoor air-flow may differ
slightly from values in the table below.
The refrigerant charge for all systems should be
checked against the Charging Chart located inside
the access panel cover.
WARNING:
The top of the scroll
compressor shell is hot. Touching the compressor top
may result in serious personal injury.
CAUTION:
R-410A pressures are
approximately 60% higher (1.6 times) than R-22
pressures. Use appropriate care when using this
refrigerant. Failure to exercise care may result in
equipment damage or personal injury.
Charge for all systems should be checked against
the Charging Chart inside the access panel cover.
IMPORTANT: Do not operate the
compressor without charge in the system.
Addition of R-410A will raise high-side pressures
(liquid and discharge).
NOTICE: System maintenance is to be
performed by a qualified and certified technician.
The optimum refrigerant charge for any outdoor unit
matched with an indoor coil/air handler is affected
by the application. Therefore, charging data has
been developed to assist the field technician in
optimizing the charge for all mounting configurations
(UF – Upflow, DF – Downflow, LH – Left-Hand
Discharge, and RH – Right-Hand Discharge). Refer
to the charging chart inside the access panel cover
on the unit and choose the appropriate column for
the specific application being installed or serviced.
New installations utilizing either an RCF indoor coil
installed on a gas furnace, RH3VZ or an RHMVZ
series air handler in the downflow or horizontal
right-hand discharge may require removal of some
refrigerant since the factory charge could result
in an overcharge condition for short line length
applications.
The following method is used for charging systems
in the cooling and heating mode. All steps listed
should be performed to ensure proper charge has
been set. For measuring pressures, the service
valve port on the liquid valve (small valve) and the
true service port located between the two service
valves are to be used.
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5.8 Refrigerant Charging
NOTE: All indoor air-ow trims must be ad-
justed using the bluetooth contractor's app.
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