1183875-YIM-A-1014
20 Johnson Controls Unitary Products
Thermostat Wiring (Not applicable to units with VFD)
The thermostat should be located on an inside wall
approximately 56 inch above the floor where it will not be
subject to drafts, sun exposure or heat from electrical fixtures or
appliances. Follow the manufacturer's instructions enclosed
with thermostat for general installation procedure. Seven (7)
color-coded, insulated wires should be used to connect the
thermostat to the unit. Refer to Table 7 for control wire sizing
and maximum length.
Figure 24: Typical Electronic Thermostat Field Wiring
Table 7: Control Wire Sizes
Wire Size Maximum Length
1
1. From the unit to the thermostat and back to the unit.
18 AWG 150 Feet
OCC
C
RC
G
Y2
Y1
W2
W1
X
R
THERMOSTAT
TERMINALS
CONTROL
TERMINAL
BLOCK
TERMINALS ON A
LIMITED NUMBER
OF THERMOSTATS
1
4
3
1
2
4
Second stageŚĞĂƟŶŐŶot required on single stage heĂƟŶg units.
Jumper is required if there is no Smoke Detector circuit.
Jumper is required for any coŵďŝŶĂƟŽŶ of R, RC, or RH.
5
5
OCC is an output from the thermostat to indicate the Occupied ĐŽŶĚŝƟon.
X is an input to the thermostat to display Error Status condiƟons.
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
Smoke
Detector
SD-R
24V Output
R
(If No Smoke Detector)
(If Smoke Detector Is Used)
208/230-3-60 and 380/415-3-50 units control
transformers are factory wired for 230v and 415v power
supply respectively. Change tap on transformer for 208-
3-60 or 380-3-50 operation. See unit wiring diagram.