Leviton omnistat 3 Directives D'installation page 6

TYPICAL WIRING DIAGRAMS
CAUTION:
• WARNING: TO AVOID DEATH OR SERIOUS PERSONAL INJURY, be sure to
disconnect the power to the control transformer before removing or installing thermostat.
• Do not short gas valve, fan, heat relay, or cool relay...even momentarily.
• Do not attempt to hook up to live circuits. An accidental connection to a component
on the thermostat circuit board could cause damage to the thermostat.
HVAC SYSTEMS
24VAC
CONTROL
TRANSFORMER
24VAC "HOT"
24VAC Common
This thermostat comes from the factory with a jumper (J3) labeled "RH-RC" on the
thermostat printed circuit board installed for HVAC systems with a single transformer.
The jumper bridges Terminal 7 (RH) and Terminal 8 (RC) on the terminal strip. For HVAC
systems with a single transformer, this jumper (J3) must remain in place.
IMPORTANT NOTES:
1. For HVAC systems with a single transformer for heating and cooling, jumper (J3)
labeled "RH-RC" on the thermostat printed circuit board, bridges Terminal 7 (RH)
and Terminal 8 (RC) and must remain in place.
2. From the factory, the RC500-2EW is configured to control a single stage
conventional HVAC system.
• If the HVAC system is a heat pump, 2-Pipe, or 4-Pipe system that requires a
sub-base, before operating the thermostat, the "System Type" settings under
"HVAC Settings" must be configured
– See Installation Settings.
Thermostat power-up for test or configuration purposes
(RC)
(C)
1 2 3 4 5 6 7 8
THERMOSTAT
Figure 4
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