Routing Power Leads Into Unit; Connecting Ground Lead To Ground Screw; Routing Control Power Wires; Accessory Installation - Carrier INFINITY 48XL-A Installation Instructions Manual

ROUTING POWER LEADS INTO UNIT

Use only copper wire between disconnect and unit. The high
voltage leads should be in a conduit until they enter the duct panel;
conduit termination at the duct panel must be watertight. Run the
high- -voltage leads through the power entry knockout on the
power entry side panel. See Fig. 5 and 6 for location and size. For
single- -phase units, connect leads to the black and yellow wires.

CONNECTING GROUND LEAD TO GROUND SCREW

Connect the ground lead to the chassis using the ground screw on
the control plate near the inducer switch (See Fig. 12).

ROUTING CONTROL POWER WIRES

For detailed instruction on the low voltage connections to the User
Interface (UI), refer to the UI installation guide.
Form a drip- -loop with the control leads before routing them into
the unit. Route the low voltage control leads through grommeted,
low- -voltage hole provided into unit (See Fig. 5 and 6). Connect
user interface leads to unit control power leads as shown in Fig. 14.
The unit transformer supplies 24- -v power for complete system
including accessory electrical heater. Transformer is factory wired
for 230- -v operation. If supply voltage is 208- -v, rewire transformer
primary as described in Special Procedures for 208- -v Operation
section.
The furnace board is fused by a board- -mounted automotive fuse
placed in series with transformer SEC1 and R circuit. The C circuit
of transformer circuit is referenced to chassis ground through a
printed circuit run at SEC2 and gas valve grounding wire. Check to
be sure control board is mounted securely using both
factory- -installed screws.

ACCESSORY INSTALLATION

A. Outdoor Air Temperature Sensor (OAT)
CAUTION
!
EQUIPMENT OPERATION HAZARD
The installation of an outdoor air temperature sensor (OAT)
using the Infinity control board OAT terminals is required.
Many Infinity features (auto humidity control, comfort
rollback, etc.) will be lost if the OAT is not connected.
For detailed mounting instructions for the OAT sensor,
please refer installation instructions shipped with the OAT.
The OAT input is used to supply outdoor temperature data for
system level functions and for temperature display on User
Interface (UI). Using two wires of the field- -supplied thermostat
wire cable, wire the ends of the two black OAT pigtails. Wire the
opposite ends of these two wires to the OAT provided with the UI.
There is no polarity to be observed.
NOTE: Mis- -wiring OAT inputs will not cause damage to either
Infinity control or thermistor. If the thermistor is wired incorrectly,
no reading will appear at UI. Re- -wire thermistor correctly for
normal operation.
B. Humidifier Connections
The furnace control board terminal marked HUM is provided for
low voltage (24- -vac) control of a humidifier. No humidistat is
required as UI monitors indoor humidity.
When commanded to operate humidifier, the unit control will
energize the HUM output to turn humidifier on and de- -energize
HUM output to turn humidifier off. Wire HUM and COM
terminals directly to humidifier as shown in Fig. 14.
C. Electronic Air Cleaner
Electronic Air Cleaner terminals are provided on the Infinity
Control Board (EAC- -1 and EAC- -2). While these terminals can be
used to power a 230V EAC, it is recommended that any EAC be
installed per the EAC installation instructions and connected
separately to a standard 115V or 230V outlet with an airflow
sensor to control operation of the EAC.

SPECIAL PROCEDURES FOR 208- -V OPERATION

Be sure unit disconnect switch is open.
Disconnect the black primary lead from the transformer. See unit
wiring label (See Fig. 16 and 17).
Connect the black primary lead to the transformer terminal labeled
208- -v.
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