Page 13
HARMONY III
T
SERIES
Component Specific Wiring
Thermostat Wiring
Using standard electronic 1-heat /1-cool non-heat pump,
non-power robbing thermostats, and five−wire thermostat
cable, wire units as follows:
1. Wire each thermostat to terminals Y, W, G, R, and C.
2. Run cable from each of the thermostats to the zone
control board. Mark each cable according to the zone
thermostat from where it originates.
3. Strip the cables and attach each of the 5 wires to the
zone control board (see figures 19, 20, 21).
Gas Furnace Wiring
After the furnace is installed, field wire the unit as de-
scribed in the installation instructions provided with the fur-
nace. Use thermostat wire to connect the furnace and the
zone control board and to connect the zone control panel
24V C" to SureLight
®
board terminal strip C" (see wiring
diagram in figure 19).
IMPORTANT
The common C" terminal of the Harmony III
t
zone
control board MUST be connected to the common
terminal of the SureLight
®
furnace board, or if using
a blower coil, MUST be connected to the common
terminal of the blower coil terminal strip.
Condensing Unit Wiring
After the condensing unit is installed, field wire the unit as
shown in the installation instructions provided with the unit.
Use thermostat wire to connect the condensing unit to the
zone control board (see figure 19).
Pressure Switch Wiring
Pull a two−wire thermostat cable from the field-installed
pressure switch to the zone control board and connect at
the pressure switch, and at the zone control board as
shown in the connection location diagram (see figure 20).
Blower Coil Wiring
After the blower coil unit is installed, field wire the unit as
shown in the installation instructions provided with the unit.
Use thermostat wire to connect the blower coil to the zone
control board (see figure 20) and to connect wire from zone
control panel 24V C" to blower coil terminal strip C".
NOTE − If not already done, remove the wire to K20 blower
relay terminal 7 (on BDC3 board) and tape it off. Also, be
sure the factory−installed jumper between terminal R and
W1, W2, and W3 has been removed.
Heat Pump Unit Wiring
After the heat pump unit is installed, field wire the unit as
shown in the installation instructions provided with the unit.
Use thermostat wire to connect the heat pump to the zone
control board (see figure 21).
Variations on Common Applications
Several variations may be required for specific applica-
tions. Figure 18 shows alternate wiring and describes spe-
cific jumper configurations and other special modifications
required for each variation.
Aside from the variations described in figure 18, the con-
nectivity is the same as shown in figure 19. Note that there
will be no Pressure Switch nor Balance Point Sensor in any
of these variations.
Figure 18
COOLING ONLY
JUMPERS: System configuration−
GAS; 1COOL or 2COOL;
Others do not matter.
BDC3 Board: As applicable, cut
jumpers and harness wires (see
Electrical Adjustments − BDC3
Board on page 7).
HOT WATER COIL (CBWMV)
JUMPERS: System configuration−
GAS; 1COOL or 2COOL;
Others do not matter.
BDC3 Board: As applicable, cut
jumpers and harness wires (see
Electrical Adjustments − BDC3
Board on page 7).
COOLING WITH ELECTRIC HEAT
JUMPERS: System configuration−HP;
1COOL or 2COOL.
E−Heat stage jumper set on # agreeing
with # of available heat stages.
E−HEAT Selector Switch always ON.
BDC3 Board: As applicable, cut jumpers
and harness wires (see Electrical Adjust-
ments − BDC3 Board on page 7).
For any option or variation, connect thermostat wire between C" on terminal strip(s) of controlled equipment and zone control board 24VAC C"
terminal.
Harmony III
t
Zone Control System − Variations on Common Applications
Y1
Y2
C
R
R
G
W1
W2
C
DS
Y1
Y2
O
RC
W1−Def
RH
G
W1
W2
W3
DS
Equipment
Equipment
CONDENSING
UNIT
Y1
Y2
C
R
R
G
W1
W2
W3
C
DS
Y1
Y2
O
RC
W1−Def
RH
G
W1
W2
W3
DS
Equipment
Equipment
CONDENSING UNIT
ELECTRIC HEAT
CBWMV
Y1
Y2
C
R
R
G
W1
W2
C
DS
Y1
Y2
O
RC
W1−Def
RH
G
W1
W2
W3
DS
Equipment
Equipment
CONDENSING
UNIT
VSM BLOWER COIL