Patent attributes
A device for detecting a wire configuration connecting a thermostat and HVAC equipment includes fan controller circuitry, AC controller circuitry, switching circuitry, and processing circuitry. The fan controller circuitry is configured to operate a fan unit of the HVAC equipment using a G pin in a first wire configuration and using a K pin in a second wire configuration. The AC controller circuitry is configured to operate an AC unit of the HVAC equipment using a Y pin in the first wire configuration and the K pin in the second wire configuration. The switching circuitry is configured to refrain from electrically coupling the Y pin and the K pin in response to a deactivation signal. The processing circuitry is configured to determine the HVAC equipment is in the first wire configuration in response to determining the AC controller circuitry receives power while outputting the deactivation signal to the switching circuitry.
