General purpose relays provide remote control over components by making or breaking an electrical connection. They are commonly connected to fans and other high-current devices and controlled using a low-power signal from a controller or thermostat.

These relays have integrated transformers to step control voltages up or down, making them compatible with other components. They connect to different HVAC systems and turn them on and off remotely.

Fan-control relays provide power to a fan's power supply when they receive signals from a thermostat or fan controller. This allows a low power device like a control board to control a high-power device such as a fan or compressor.

These relays provide control over fans by switching their power supply on or off. They feature transformers to adjust the control signal and ensure that the supplied voltage is compatible with the connected fan.

These relays control electric resistive heating components such as baseboard heaters and electric furnaces by switching their power supply on or off. They feature transformers to adjust the control signal and components that withstand the high currents associated with electric heaters.