3-2
Module 4 –
Wireless HVAC Thermostats
ST898ZB Optima S Thermostat
Section 3
Step 1.
Determine the desired wiring configuration for the ST880ZB Thermostat . The following
chart shows the terminal designations for gas, electric or oil (Non-HP) and heat pump (HP)
installations . Appendix A provides reference wiring diagrams for typical thermostat installations .
Installation – Mounting & Wiring
Table 2.1: ST880ZB Optima Zigbee Thermostat Wiring Reference
Gas, Electric or Oil (Non-HP)
Heat Pump (HP)
RjP
Power Jumper (RH)
RC
24 VAC for Cooling System or Jumper to RjP
RH
24 VAC for Heating System
24 VAC for Heat Pump
C
24 VAC Common Return
Y1
Single / 1st Stage Cooling
Single / 1st Stage Compressor
Y2
2nd Stage Cooling
2nd Stage Compressor
W1AX
Single / 1st Stage Heating
Auxiliary or Emergency Heat
W2OB
2nd Stage Heating
Changeover Valve
G
Fan Signal
L
Reserved
System Monitor
Step 2.
If replacing an existing thermostat, review and record the existing wiring configuration:
• Remove thermostat from the wall to expose the wiring terminals
• Take a photograph or note the wire colors and designations (see wiring reference above)
• Attach wire labels provided to each of the existing thermostat wires
Step 3.
Remove existing thermostat .
BEFORE BEGINNING the installation procedure,
turn off power to the heating system .
LABEL WIRES TO CORRESPOND
TO THERMOSTAT TERMINALS
WRAP WIRES AROUND A PENCIL OR
SIMILAR OBJECT TO PREVENT THEM
FROM FALLING INTO THE WALL VOID
