Surge Protection for Industrial Sites

OVERVIEW

The equipment used in your manufacturing facilities are very sensitive and vulnerable to lightning and switching surges. The cost of fully surge protecting an industrial plant is limited and provides peace of mind that your system will be operational when you need it most.

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Surge Protection for Industrial Machinery


Surge Protection for Industrial Machinery

NFPA 70 Article 670.6 (NEC 2026)
NFPA 79 Electrical Standard for Industrial Machinery (2026)
Metal-Workshop
NFPA 79 Industrial Machinery in a metal workshop

NEC-2020 The latest release of NEC/NFPA 70 edition 2026 (NEC 2026) has placed a greater emphasis on increasing personnel safety by mandating the use of Surge Protective Devices (SPDs).

From 2014 to 2025, the number articles now requiring SPDs has increased significantly for applications ranging from Modular Data Centers, Fire Pumps, Elevators, Critical Power Systems, Dwellings (Dormitories, Homes, Hospitals, Hotels), etc.

Threat to industrial machines

Various codes and standards possess safety interlock criteria including the American National Standards Institute (ANSI) standards and NFPA 79 for Industrial Machinery. However, until now, these standards have only just begun to address the expanding role that surge protection plays preserving the integrity of equipment and, more importantly, protecting the lives of personnel.

A study commissioned by the Fire Protection Research Foundation, “Data Assessment for Electrical Surge Protective Devices”, provides results of a survey of facility managers concerning surge damage. (NFPA 2014) The study shows that 26 percent of facility managers surveyed observed damage to safety interlocking systems on industrial machines due to surges . The main purpose of these safety interlocking systems is to protect workers and maintenance personnel from contact with exposed live parts and electric shock. Failure of these devices can put personnel at an increased risk of injury.

Computerized-Lathe
CNC lathe

The solution for NFPA 70 and NFPA 79

To make the installation of a Surge Protective Device (SPD) at the industrial machines interlocking safety circuit mandatory which in turn increases the equipments reliability.

NFPA 70 Article 670.6 Surge Protection.
"Industrial machinery with safety circuits shall have overvoltage protection.”
NFPA 70 Article 409.70 Surge Protection.
"Safety circuits for personnel protection that are subject to damage from surge events shall have surge protection installed within or immediately adjacent to the control panel."
NFPA 79 Article 7.8.1 Surge Protective Devices (SPDs).
"Industrial machinery with safety circuits shall have SPD(s) to protect against the effects of overvoltages due to transients or switching surges. The type of SPD(s) shall be selected to protect, at a minimum, the safety circuit devices and shall be permitted to be integral to secondary derived voltage sources.”

Selecting an SPD for Industrial Machinery

NEC/NFPA 70 require that Surge Protective Devices (SPDs) shall be UL1449 Listed . This means selecting a surge protector is easier than it has ever been. There are only a few choices available for SPDs that are UL Listed for any of the most commonly used surge standards including UL1449 5th Edition, UL497B, and UL497E.

Recommended SPD for Industrial Machines

LocationEquipmentSystemSurge Protector Model#Link
Service EntranceMain Service Panelboard277/480Vac MDS750E-277Y MDS750E-480D
Branch PanelEquipment Panelboard480Vac M50-480D-A M50-A
Local EquipmentControl Panel480Vac Power Input DS74US-480D DS74US-480D

Power Supply120-240Vac Power Input DS72US-230S/G DS72US-120S/G

24Vdc Power Output DS220S-24DC DS220S-24DC

Control UnitEthernet Cat 6A MJ8-C6A MJ8-C6A

4-20mA DLA-24D3 DLA-24D3 v.2

Wireless P8AX09-6G-N/FF P8AX09-6G-N-FF

Types of machines covered by NFPA 79

TypeDescription
Machine ToolsMetal Cutting
Metal Forming
Plastics MachineryInjection molding machines
Extrusion machinery
Blow molding machines
Specialized processing machines
Thermostat molding machines
Size reduction equipment
Wood MachineryWoodworking machinery
Laminating machinery
Sawmill machinery
Material-Handling MachineryIndustrial robots
Transfer machines
Sortation machines
Inspection/Testing MachinesCoordinate measuring machines
In-process gauging machines
Packaging MachinesCarton-strapping machines
Drum-filling machines
Palletizing machines

Standard and Electric Code References for Surge Protective Devices

#Title
1NFPA 70 edition 2026, Article 670 Industrial Machinery, 670.6 Surge Protection
2NFPA 70 edition 2020, Article 670 Industrial Machinery, 670.6 Surge Protection
3NFPA 70 edition 2017, Article 670 Industrial Machinery, 670.6 Surge Protection
4NFPA 70 edition 2014, “Data Assessment for Electrical Surge Protective Devices”
5NFPA 79 edition 2026, Electrical Standard for Industrial Machinery, Chapter 7, 7.8 Protection Against Overvoltages Due to Lightning and Switching Surges 7.8.1 Surge Protective Devices (SPDs)
6NFPA 79 edition 2018, Electrical Standard for Industrial Machinery, Chapter 7, 7.8 Protection Against Overvoltages Due to Lightning and Switching Surges 7.8.1 Surge Protective Devices (SPDs)
7NFPA 79 edition 2018, Annex C, Examples of Industrial Machines Covered by NFPA79
8ANSI C62.41, Low-Voltage AC Power Circuits
9UL1449 4th Edition, Surge Protective Devices
10UL1449 5th Edition, Surge Protective Devices
11UL497B, Surge Protectors for Data Lines and Fire-Alarm Circuits
12UL497E, Antenna Lead-in Conductors
13IEC 61643-11, Low-Voltage Surge Protective Devices - Part 11: Surge Protective Devices Connected To Low-Voltage Power Systems - Rquirements And Test Methods
14IEC 61643-21, Low Voltage Surge Protective Devices - Part 21: Surge Protective Devices Connected To Telecommunications And Signalling Networks - Performance Requirements And Testing Methods
15IEC 61000-45, Electromagnetic Compatibility (EMC) - Part 4-5: Testing And Measurement Techniques - Surge Immunity Test
16CSA 22.2
17NOM-001-SCFI, Standard for Electronic Equipment
18NOM-003-SCFI, Electrical Products - Safety Requirements
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