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4.0 INSTALLATION
4.9 Control Wiring (cont.)
4.10 Power Wiring
TYPICAL 2-STAGE THERMOSTAT: (-)A20 AIR CONDI-
TIONER WITH ELECTRIC HEAT USING A HUMIDISTAT
FOR DEHUMIDIFICATION
W1
W2
Y1
Y2
R
C
G
ODD
Y1 Y2 G W1 W2 C
R
Y
Y2
R
C
W/BK
W/BL
Y
Y/BL
R
BR
G
Typical Two-Stage Thermostat
(-)A20
Outdoor Unit
(-)HMV
Air Handler
Field-Installed
Factory Standard
Humidistant
TYPICAL 2-STAGE THERMOSTAT: AIR CONDITIONER
AND FURNACE
R
C
W1
W/E
Y
Y2
G
R
C
Y
Y2
R
C
W1
Y1
Y2
G
W2
W2
Typical
Two-Stage
Thermostat
(-)A20
Outdoor Unit
Furnace
Control
Field wiring must comply with the National Electric
Code (C.E.C. in Canada) and any applicable local
code.
Wiring
It is important that proper electrical power is
available at the outdoor unit power terminal block.
The acceptable operating voltage range is shown below.
VOLTAGE RANGES
Nameplate
Voltage
Operating Voltage Range at
Maximum Load Conditions
208/230 (1 Phase)
197-253
Install a branch circuit disconnect within sight of the
unit and of adequate size to handle the minimum circuit
ampacity (MCA) current (see “Electrical Data” in Section
3.2).
Field wiring must comply with the National Electric Code
(C.E.C. in Canada) and any applicable local code.
Power wiring must be run in a rain-tight conduit.
Conduit must be attached to the hole in the bottom of the
control box.
Connect power wiring to line-voltage lugs on the terminal
block located in the outdoor unit electrical box. (See wiring
diagram attached to unit access panel.)
Check all electrical connections, including factory wiring
within the unit and make sure all connections are tight.
DO NOT
connect aluminum field wire to the line voltage
terminal block.
ST-A1241-02-X0
Line Voltage Terminal Block
Ground Lug