An Automatic Transfer Switch (ATS) can be connected to a Leviton Whole Home Energy Monitor (LWHEM) using the blue wire loop found behind the sticker on the LWHEM.
The blue wire should be cut and extended to connect to the Automatic Transfer Switch (ATS). During normal operation the loop should be closed. When the loop opens the Leviton Load Center will turn off breakers designated as a Non-Essential circuit in the My Leviton App.
A wiring example is utilizing the Auxiliary Contact available on the Generac RWSC100A3, RWSC200A3, RWSW100A3, RWSW150A3 and RWSW200A3 Automatic Transfer Switches.
As shown in the Generac manual:
- Cut the blue loop on the LWHEM
- Use conductors with proper insulation for the application and connect the two normally closed connections on the Auxiliary Contact
- The LWHEM will monitor a set of dry contacts
- No voltage from the transfer switch will be connected to the LWHEM
- Any connection other than dry contact will damage the LWHEM
- If an auxiliary contact is not available, a contactor may be needed to isolate 120VAC from the LWHEM blue loop connection
When the transfer switch is using utility power the contacts will be closed. If utility power is not available and the transfer switch changes to generator the contacts will open. The LWHEM will boot using power from the generator.
- During the startup the blue loop will be seen as open causing the LWHEM to turn off Leviton Gen 2 Smart Circuit Breakers with Remote Control designated in the app as Non-Essential.
- When utility power is restored the transfer switch will return to the normal state and the contacts will close. The contacts closing will return Non-Essential breakers to their normal operating state.
Note: Gen 1 Smart breakers are compatible with the LWHEM; however, they cannot be controlled as a Non-Essential circuit.