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Install disconnect switch and power wiring in accordance with
all applicable local codes. See Fig. 13-15 and the unit label
diagram. Connect power wiring with 1/4 in. ring terminal.
Electric
Disconnect
Switch
Fig. 13 — Disconnect Switch and Unit
Fan Scroll
Motor and
Drive
Condensate
Drain
Connection
(Horizontal)
Filter
Elements
Filter
Retainer
Clip
LEGEND
TXV — Thermostatic Expansion Valve
Fig. 14 — Wiring and Service Access
(Side Panel Removed)
Fan motors are factory-installed on all units. The control box
(see Fig. 15) contains a Unit Control Board (UCB) that re-
ceives thermostat commands from the thermostat (through
the Thermostat Connection Board [TSTAT CB]) and outputs
these commands to the condensing unit (through the Indoor
Connection Board [IDCB]). The control box also contains a
high voltage terminal block and fuses that provide overcur-
rent protection to the Variable Frequency Drive.
Complete 24-v control circuit wiring. Wire the thermostat to
TSTAT CB terminal block (see Fig. 15), according to Fig. 16
and the unit label diagram. If the air handler is part of a split
system, complete the wiring from the condensing unit to the
IDCB terminal block (see Fig. 13). Refer to Fig. 16 and the
unit label diagram.
THREE STAGE OPERATION
All units are factory shipped for 2-stage cooling operation.
To convert a unit to 3-stage operation, see Fig. 17 adjust the
FAS-FHS-240-336-02SI
Copper
Wire Only
Aluminum
Wire
Control
Box
Fan
Drive
Pulley
Wire
Access
Coil
TXV
Bulb
Access
Refrigerant
Piping
Access
Condensate
Drain
Connection
(Vertical)
Specifications subject to change without notice.
following wires between the control board and two terminal
strips on the side of the control box:
1. Remove gray wire from Thermostat CB terminal X.
2. Move orange wire from Thermostat CB terminal Y2 to
terminal X.
3. Make connections of blue wire included in factory har-
ness. Connect one end to Thermostat CB terminal Y2
and the other to Indoor Connection Board terminal Y2.
4. Move orange wire from Indoor Connection Board termi-
nal Y2 to terminal X.
The 3-stage system will run the fan at low speed with a G,
Y1, and Y1+Y2 call, and at high speed with a call for Y1, Y2,
and Y3. A thermostat with 3 cooling stage capability is re-
quired for this system configuration.
Indoor
Connection
Board
(IDCB)
Thermostat
Connection
Board
(TSTAT CB)
High
Voltage
Terminal
Block
Exit for
Power Wiring
Fig. 15 — Control Box (Cover Removed) (Typical)
FREEZE PROTECTION
On select models, there is a factory-installed and wired tem-
perature switch (HH18HB016) to protect the compressor(s)
in the condensing unit when frost buildup is present on the
indoor coil. The temperature switch is used to prevent the
compressor(s) from turning on while the indoor coil is
frosted. Refer to the unit wiring label diagram for wiring of
this switch.
Unit
Control
Board
Fuse
Block
and
Fuses
Ground
Lug
Exit for
Low Voltage Wiring
19
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