how to test industrial relay with multimeter： a step-by-step guide
Release time:2025-09-19 09:33:52
Industrial relays are essential components in many automation systems, as they are responsible for controlling circuits by opening or closing contacts in response to electrical signals. Testing these relays for faults or failures is critical to ensure the smooth operation of machinery. One of the most straightforward methods for testing industrial relays is by using a multimeter, which allows you to check the resistance, continuity, and voltage across different contacts and coil terminals. In this article, we will walk you through how to test industrial relays using a multimeter.
Step 1： Understanding the Components of a Relay
Before you begin testing, it’s important to understand the basic components of a relay：
Coil： The coil is the electromagnetic part of the relay that gets energized and creates a magnetic field when current passes through it.
Common Terminal (COM)： This is the terminal that is typically connected to the load or circuit that you want to control.
Normally Open (NO)： The NO contact is open when the relay is de-energized, and it closes when the relay is activated.
Normally Closed (NC)： The NC contact is closed when the relay is de-energized, and it opens when the relay is activated.
Chat Oline