Overview

Sudden fluctuations in generation, load, or transmission parameters can lead to power surges within electrical systems, posing a threat to sensitive electronic equipment. These surges can be mitigated by installing properly sized surge protection equipment to redirect voltage spikes.

The 2023 edition of the NEC introduced Section 409.70 to address the previously overlooked issue of surge protection for industrial control panels. This section specifies installation requirements for surge protection devices, mandating that they be installed inside or adjacent to the protected control panel. These new provisions enhance the safety and reliability of the panel by shielding it against potential surges.

Applying the 2023 Code

Industrial control panels are assemblies that consist of multiple components such as motor controllers, switches, and relays, which are housed in enclosures or mounted on back panels. These panels are used to monitor and control processes and machinery efficiently in industries such as manufacturing, processing, and automation, where precise control and monitoring are crucial for ensuring smooth operations.

Furthermore, these panels serve a crucial role in protecting machinery, including motors and power connections, from power surges. These surges, resulting from sudden changes in load, generation, or transmission systems, present significant risks to sensitive electronic equipment. Surge protection devices, such as surge protectors and suppressors, are typically installed on such equipment and systems to divert excess voltage, ensuring equipment integrity and longevity in various settings.

However, the 2020 edition of the NEC did not address the installation or usage of surge protection for industrial control panels and their safety circuits. To bridge this gap, the 2023 NEC introduced a new Section, 409.70, which outlines installation requirements for surge protection equipment for control panels. These new provisions permit surge protection devices to be installed inside or in close proximity to the control panel, thereby enhancing the safety and reliability of industrial control panel operations by protecting them from surges.

What’s New for the 2023 NEC?

The table below presents a comparison between the 2020 NEC and the 2023 NEC regarding Section 409.70.