The Smart Relay is designed for medium load applications, and therefore, medium gauge wiring is suitable for the wiring requirements.

The input power wiring is a DC voltage that is connected to the bottom left terminal block. The input is polarised and protected by an input diode that protects the board.

The primary trigger for the Smart Relay is the opto-coupled input. This is triggered when the contacts are shorted to ground, or the two pins are connected together. When the pins are connected together, the opto has an LED that illuminates, indicating that an input is present.

As with a standard relay, it has three contact points: Common, Normally Open, and Normally Closed. These connections are indicated on the PCB.

The transistor is configured electrically as a switch and switches to ground when actuated.