5703827-XIM-A-0319
Johnson Controls Ducted Systems
21
Thermostat wiring
A two stage thermostat must be used and located on an inside wall approximately 56 inches above the floor. The thermostat must
not be subject to drafts, sun exposure, or heat from electrical fixtures or appliances. Follow the manufacturer's instructions enclosed
with thermostat for the general installation procedure. Eight (8) color-coded, insulated wires must be used to connect the thermostat
to the unit. See Table 10 for the control wire sizing and maximum length.
Control wiring
Figure 18: Typical Smart Equipment™ control wiring
Control wiring legend
The R~Occ Jumper: Smart Equipment™ Control boards come from the factory with a jumper wire between the R and OCC terminals
on the thermostat terminal strip. Failure to remove this jumper places the unit into the occupied mode no matter what the occupancy
demand is from the thermostat or EMS system. To allow Thermostat or EMS control of the occupied mode for the unit, remove this
jumper during commissioning.
Table 10: Control wire sizes
Wire size
Maximum length
1
1.From the unit to the thermostat and back to the unit.
18 AWG
150 feet (46 meters)
1 Second stage heating is not required on single stage heating units.
4 OCC is an output from the thermostat to indicate the occupied condition.
2 Jumper is required if there is no Smoke Detector circuit.
5 X is an input to the thermostat to display error status conditions.
3 Jumper is required for any combination of R, RC, or RH.
OCC
C
RC
G
Y2
Y1
W2
W1
X
R
4
5
3
W2
Y1
G
OCC
Y2
X
R
SD-24
C
W1
2
24V
C
24 VAC
Class 2
SD-24
Jumper Located on Harness
SD-R
24V Output
R
(If No Smoke Detector)
(If Smoke Detector Is Used)
1
Terminals on a limited
number of thermostats
Thermostat
terminals
Control
terminal
block
Smoke
detector
