6
MAXIMUM ALLOWABLE LENGTH IN FEET TO LIMIT
VOLTAGE DROP TO 2%
Wire
Size
Minimum Circuit Ampacity (MCA)
(AWG)
10
15
20
25
30
35
40
45
14
77
51
38 NR NR NR NR NR
12
122 81
61
49
NR NR NR NR
10
193 129 97
77
64
55 NR NR
8
307 205 154 123 103 88
77
68
Local codes often require a disconnect switch located near
the unit; do not install the switch on the unit. Refer to the
installation instructions supplied with the indoor furnace /
air handler for specific wiring connections and indoor unit
configuration. Likewise, consult the instructions packaged
with the thermostat for mounting and location information.
WARNING
HIGH VOLTAGE!
Disconnect all power before servicing.
Multiple power sources may be present.
Failure to do so may cause property damage,
personal injury or death due to electric
shock. Wiring must conform with NEC or CEC
and all local codes. Undersized wires could
cause poor equipment performance, equipment
damage or fire.
WARNING
To avoid the risk of fire or equipment damage, use copper
conductors.
NOTICE
Units with rotary or reciprocating compressors and non-
bleed TXV’s require a Hard Start Kit.
THERMOSTAT
2-STAGE HEATING WITH
2-STAGE COOLING
Two-Stage Thermostat
with Three Low Voltage Wires to
Remote
2
2
2
1
2
1
1
2
Two-Stage Thermostat
with Three Low Voltage Wires to Remote
Overcurrent Protection
The following overcurrent protection devices are approved
for use.
• Time delay fuses
• HACR type circuit breakers
These devices have sufficient time delay to permit the
motor-compressor to start and accelerate its load.
Three Phase Compressor Rotation
CAUTION
Use care when handling scroll compressors. Dome
temperatures could be hot.
Three phase compressors are power phase dependent
and can rotate in either direction.
Verify proper rotation for three phase compressors by
ensuring the suction pressure drops and discharge
pressure rises when the compressor is energized.
NOTE: When operated in reverse, a three phase
scroll compressors is noisier and its current
draw substantially reduced compared to marked
values.
To correct, disconnect power and switch any two leads at
the unit contactor and re-observe.
High Voltage Connections
Route power supply and ground wires through the high
voltage port and terminate in accordance with the wiring
diagram provided inside the control panel cover.
Low Voltage Connections
Condensing unit control wiring requires 24 Volt minimum,
25VA service from the indoor transformer. Low voltage
wiring for two-stage units depends on the thermostat used
and the number of control wires between the indoor unit
and the condensing unit. Route control wires through the
low voltage port and terminate in accordance with the
wiring diagram provided inside the control panel cover.
THERMOSTAT
SINGLE-STAGE HEATING
WITH
SINGLE-STAGE COOLING
Single-Stage Thermostat
with Two Low Voltage Wires to Remote
