---
title: Wiring
slug: wiring
docTags: 
createdAt: 2025-08-08T10:02:18.835Z
---

# Wiring Requirements

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

## Input Power Wiring

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.

## Input Signal Wiring

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.

## Relay Wiring

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

## Transistor Actuator

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