Page 14
506083−01 03/08
5. Install low−voltage wiring from outdoor to indoor unit
and from thermostat to indoor unit.
R
W1
Y
G
C
R
W
Y
G
C
THERMOSTAT
INDOOR UNIT
POWER
HEAT
COOLING
INDOOR BLOWER
COMMON
OUTDOOR UNIT
Y1
C
Figure 25. Low Voltage Wiring Diagram
(Typical Field Wiring)
Table 3. Wire Run Lengths
Wire Run Length
AWG #
Insulation Type
Less than 100 feet
(30m)
18
Color−coded with a
minimum temperature
rating of 35
º
C.
More than 100 feet
(30m)
16
6. Do not bundle any excess 24V control wire inside
control box. Run control wire through installed wire tie
and tighten wire tie to provided low voltage strain relief
and to maintain separation of field installed low and
high voltage circuits as illustrated in figure 25.
NOTE −
24VAC, Class II circuit connections are made in
the low voltage junction box
NOTE − To facilitate conduit, a hole is in the bottom of the
control box. Connect conduit to the control box using a
proper conduit fitting.
NOTE − Units are approved for use only with copper
conductors.
NOTE − A complete unit wiring diagram is located inside
the unit control box cover.
NOTE − See unit wiring diagram for power supply
connections. If indoor unit is not equipped with blower
relay. It must be field−provided and installed (P−8−3251 or
equivalent)
THREE-PHASE SCROLL VOLTAGE PHASING
Three-phase scroll compressors must be phased
sequentially to ensure correct compressor rotation and
operation. Incorrect line voltage phasing may cause
compressor damage and abnormal unit operation. Power
wires are color-coded as follows: Line 1 − red, line 2 − yellow,
line 3 − blue.
1.
Cooling demand imitates a 24VAC signal from Y1 in the thermostat.
2.
24VAC from indoor unit Y1 energizes contacts K1−1, K1−2 and K1−3.
3.
K1−1, K1−2 and K1−3 N.O. close, energizing compressor B1 and
outdoor fan motor B4.
END OF COOLING DEMAND:
1.
Cooling demand is satisfied. Terminal Y1 is de−energized.
2.
Compressor contacts K1−1, K1−2 and K1−3 are de−energized.
3. K1−1,
K1−2 and K1−3 open and compressor B1 and outdoor fan motor
B4 are de−energized and stop immediately.
COOLING:
Note: The thermostat used may be electro−me-
chanical or electronic.
Figure 26. Typical Unit Wiring Diagram
