The Importance of NEC Class 2 Protection in Industrial Automation Systems

As a Controls Engineer, ensuring both operational efficiency and safety in industrial environments is one of my core responsibilities. One of the most effective methods to achieve this balance is through the implementation of NEC Class 2 Protection in circuits that supply power to industrial sensors and components. NEC Class 2 circuits are designed to limit both current and voltage, minimizing the risk of electrical shock and reducing potential damage to equipment. This is particularly important for ensuring maximum runtime and performance of Allen-Bradley^® sensors and industrial automation devices.

I’ve seen photoelectric sensors, capacitive sensors and temperature sensors frequently deployed in food processing facilities, where reliability and uptime are critical, and where harsh environmental conditions (such as moisture, high temperatures and vibrations) are common. I always recommend using a 1606 Series Power Supply in conjunction with a 1694 Electronic Circuit Protector module as a Class 2 power solution. This combination provides these sensitive devices with consistent voltage regulation and short-circuit protection.

When it comes to NEC Class 2 Protection, it’s important to never compromise on consistency. For instance, think about a mid-sized food processing plant operating multiple conveyor lines equipped with photoelectric sensors to detect product positioning, capacitive sensors to monitor fill levels in packaging lines and temperature sensors for precise thermal management of cooking and cooling processes. Without consistent NEC Class 2 Protection, a minor wiring fault in one of the conveyor sensor circuits could result in an overcurrent condition, damaging sensors, triggering false alarms or causing a localized electrical fire. Any one of these effects would halt production for at least a few hours.

The costs associated with this kind of event are significant. Sensor replacement and system troubleshooting can quickly accumulate thousands of dollars in direct expenses, while the indirect costs of lost production, missed delivery deadlines and spoiled food products can easily exceed tens of thousands of dollars. An electrical incident in a food processing environment also leads to compliance/safety risks and the potential for regulatory fines or mandatory facility shutdowns.

With dependable NEC Class 2 Protection implemented, any overcurrent condition is confined to the protected circuit. If a 1694 Electronic Circuit Protector is in place, the fault would be isolated to a single sensor or device instead of affecting an entire machine or production line. The combination of a 1606 Power Supply with 1694 ECP modules ensures that even if a sensor fails, the fault remains contained, protecting both equipment and personnel while reducing overall operational impact.

NEC Class 2 Protection is critical when designing safe and reliable industrial automation systems. Allen-Bradley sensors and devices, when powered through Class 2 circuits with 1606 Power Supplies and 1694 Electronic Circuit Protectors, benefit from enhanced safety, reduced downtime and simplified maintenance. In an environment where both operational continuity and personnel safety are prioritized, NEC Class 2 Protection is not just my recommendation; it’s an essential investment.