Leviton omnistat 3 Directives D'installation page 7

TYPICAL WIRING DIAGRAMS - Continued
3. If the HVAC system is a two stage conventional or two speed heat pump, before
operating the thermostat (making a call for heat or cool), the "Cool Stages"
and "Heat Stages" settings under "HVAC Settings" must be configured – See
Installation Settings.
4. When configured as a conventional thermostat, by default this thermostat does
not turn the fan on with a call for heat. If the furnace requires the thermostat to
turn the fan on with a call for heat, configure "Fan With Heat" to "Enabled" under
"HVAC Settings".
5. Refer to the "Configuration" steps under the wiring diagram for the respective
HVAC system type.
6. If the thermostat or HVAC system does not perform as stated in the "Power Up"
steps under the wiring diagram for the respective HVAC system, recheck all
wiring - See Troubleshooting Tips.
7. For HVAC systems with separate heating and cooling transformers, the jumper
(J3) labeled "RH-RC" on the thermostat printed circuit board must be removed –
See Figure 5.
Connections for heat and cool transformers - applies to all systems
24VAC
HEAT
TRANSFORMER
HVAC SYSTEMS
24VAC
COOL
TRANSFORMER
24VAC Heat "HOT" (RH)
(C)
24VAC Common
1 2 3 4 5 6 7 8
THERMOSTAT
Figure 5
5