Industrial relays are essential components in various electrical and automation systems. They allow low-voltage circuits to control high-power applications, which makes them a critical part of machines, control systems, and safety features in industrial setups. A malfunctioning relay can cause system failures or unsafe operations, so regular testing is important. One of the most effective ways to test an industrial relay is by using a multimeter. This guide will walk you through the steps for testing an industrial relay with a multimeter to ensure it is working properly.

1. What is an Industrial Relay? Before diving into testing, it’s important to understand what an industrial relay is and how it works. A relay is an electrically operated switch that uses an electromagnet to control the opening and closing of contacts in a circuit. It typically consists of a coil (the electromagnet) and one or more sets of contacts, which can be normally open (NO) or normally closed (NC). When voltage is applied to the coil, it generates a magnetic field that causes the contacts to either open or close, depending on the relay’s design. 2. Necessary Tools To test an industrial relay, you will need the following tools：