TECHNICAL FIELD

This disclosure relates to thermostats configured to maintain a system temperature to a set of desired setpoints, such as, for example, building heating, central heating, air conditioners, heating, ventilation, and air conditioning (HVAC) systems, and other thermostats.

BACKGROUND

Thermostats may control heating, ventilation, and air conditioning (HVAC) equipment in a closed clop to reduce error between a desired set point or set of desired setpoints. Thermostats may be configured in a C configuration, where a thermostat controls a fan unit using a R wire and a G wire and controls an air conditioner unit using the R wire and a Y wire. However, to reduce a number of wires that are routed between HVAC equipment and the thermostat, some thermostats may be configured in a wire saver configuration, where the thermostat controls the fan unit using a R wire and a K wire and controls the air conditioner unit using the R wire and the K wire. In this way, the thermostat may control HVAC equipment using two wires instead of three wires, which may help to simplify connection of the thermostat to the HVAC equipment.

SUMMARY

In general, the disclosure is directed to devices, systems, and techniques for detecting a wire configuration connecting a thermostat and heating, ventilation, and air conditioning (HVAC) equipment. For example, techniques described herein may include processing circuitry configured to determine whether HVAC equipment is configured in a first wire configuration (e.g., a C wire configuration) or a second wire configuration (e.g., a K wire configuration) based on whether fan controller circuitry and/or Air Conditioning (AC) controller circuitry is receives power from a power supply. In this way, the processing circuitry may determine a wire configuration without relying on an input from a user or customer. Moreover, in some examples, the processing circuitry may determine whether a pin has been incorrectly wired, which may help to reduce a setup time and improve a reliability of the HVAC equipment.

In one example, a device for detecting a wire configuration connecting a thermostat and HVAC equipment includes: fan controller circuitry configured to operate a fan unit of the HVAC equipment, wherein the fan controller circuitry operates the fan unit using a G pin when the HVAC equipment is arranged in a first wire configuration and wherein the fan controller circuitry operates the fan unit using a K pin when the HVAC equipment is arranged in a second wire configuration; AC controller circuitry configured to operate an AC unit of the HVAC equipment, wherein the AC controller circuitry operates the AC unit using a Y pin when the HVAC equipment is arranged in the first wire configuration and wherein the AC controller circuitry operates the AC unit using the K pin when the HVAC equipment is arranged in the second wire configuration; switching circuitry configured to electrically couple the Y pin and the K pin in response to an activation signal and to refrain from electrically coupling the Y pin and the K pin in response to a deactivation signal; and processing circuitry configured to determine the HVAC equipment is arranged in the first wire configuration in response to determining the AC controller circuitry receives power from a power supply while outputting the deactivation signal to the switching circuitry.

In another example, a method for detecting a wire configuration connecting a thermostat and HVAC equipment includes: outputting, by processing circuitry, a deactivation signal to switching circuitry, wherein the switching circuitry is configured to refrain from electrically coupling a Y pin and a K pin in response to the deactivation signal, wherein the fan controller circuitry operates a fan unit of the HVAC equipment using a G pin when the HVAC equipment is arranged in a first wire configuration and wherein the fan controller circuitry operates the fan unit using the K pin when arranged in a second wire configuration; wherein the AC controller circuitry operates the AC unit using the Y pin when the HVAC equipment is arranged in the first wire configuration and wherein the AC controller circuitry operates the AC unit using the K pin when the HVAC equipment is arranged in the second wire configuration; and determining, by processing circuitry, the HVAC equipment is arranged in the first wire configuration in response to determining the AC controller circuitry receives power from a power supply while outputting the deactivation signal to the switching circuitry.

In another example, a system for detecting a wire configuration connecting a thermostat and HVAC equipment includes: a power supply; fan controller circuitry configured to operate a fan unit of the HVAC equipment, wherein the fan controller circuitry operates the fan unit using a G pin when the HVAC equipment is arranged in a first wire configuration and wherein the fan controller circuitry operates the fan unit using a K pin when the HVAC equipment is arranged in a second wire configuration; AC controller circuitry configured to operate an AC unit of the HVAC equipment, wherein the AC controller circuitry operates the AC unit using a Y pin when the HVAC equipment is arranged in the first wire configuration and wherein the AC controller circuitry operates the AC unit using the K pin when the HVAC equipment is arranged in the second wire configuration; switching circuitry configured to electrically couple the Y pin and the K pin in response to an activation signal and to refrain from electrically coupling the Y pin and the K pin in response to a deactivation signal; and processing circuitry configured to determine the HVAC equipment is arranged in the first wire configuration in response to determining the AC controller circuitry receives power from the power supply while outputting the deactivation signal to the switching circuitry.

The summary is intended to provide an overview of the subject matter described in this disclosure. It is not intended to provide an exclusive or exhaustive explanation of the systems, device, and methods described in detail within the accompanying drawings and description below. Further details of one or more examples of this disclosure are set forth in the accompanying drawings and in the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims.

