Johnson Controls GLAS - Page 15

GLAS Smart Thermostat Technical Bulletin
15
RH
W2
W1
RC
C
O
Y2
Y1
G
AUX
NOTE: When there is only
one transformer, the RC terminal
is used.
NOTE: Forced air heating systems
often have a G wire to run the fan
independently, but not all systems
use a G wire.
Furnace
CRRun
Furnace Powered
AUX Device
HVAC System
Control Board
Heat
Stage 1CRC
RC W1
C
Figure 8: Traditional Heat
RC
RC
C
C
G
Fan
Y1
Cool
Stage 1
HVAC System Control Board
RH
W2
W1
RC
C
O
Y2
Y1
G
AUX
C
R
Run
Furnace Powered
AUX Device
Outdoor AC Unit
Air Handler
Figure 9: Traditional AC
RH
W2
W1
RC
C
O
Y2
Y1
G
AUX
Switch
Coil
AUX Device
AUX Device
C
AUX
R
24 VAC
AUX
Relay
RC
RC
C
C
HVAC System
Control Board
Figure 10: Self-Powered Auxiliary Device