Arc Flash Protection: What Does NBR 17227 Say?

First and foremost, it is essential to understand why arc flash protection has become one of the most critical safety pillars in industrial electrical engineering. The increasing complexity of electrical systems, combined with high-energy-density environments such as heavy industries, demands faster and more effective mitigation technologies.

The recently revised ABNT NBR 17227 standard provides guidelines for managing the risks associated with incident energy, with a focus on technical precautions and calculation methods aimed at arc flash control. This regulatory milestone clearly and technically outlines mitigation actions, offering practical guidance for manufacturers, designers, integrators, and end users.

What Is Arc Flash and Why Is It So Dangerous?

An arc flash occurs when the insulating medium (typically air) breaks down, causing an electrical discharge between energized conductors. This discharge releases extreme heat within milliseconds — enough energy to cause severe burns, melt metal, and trigger explosions.

The greatest technical challenge is not merely preventing arc flash from occurring but drastically reducing the time between arc initiation and the system’s protective response. This is where ultrafast detection technologies come into play. 

Arc Quenching Devices and NBR 17227 

The standard outlines several approaches to arc flash mitigation, including:

• Reinforced equipment structures to withstand arc blast pressure;
• High-performance thermal PPE;
• More sensitive protection relays;
• Modern, high-speed circuit breakers;
• Arc detection and quenching systems.

Among these, arc detection and quenching systems stand out as the most effective at reducing incident energy because they directly impact response time.

The shorter the response time, the lower the incident energy. This is the only adjustable parameter that doesn’t require modifying the installed load.

Technical Comparison of Detection Technologies

Ultraviolet (UV) detection offers a decisive advantage: it identifies the arc in the pre-arc phase — even before visible light is emitted. This enables immediate operation of circuit breakers and disconnects, with response times significantly faster than traditional systems based on visible light and current measurement.

This difference can determine whether an event remains under control or escalates into a serious accident.

At Varixx, all products in the ZYGGOT Arc line incorporate UV sensors with ultrafast detection capability.

NBR 17227 Emphasizes Effectiveness and Practicality

The standard reinforces that the most recommended solutions must combine::

• High effectiveness in reducing incident energy;
• Easy implementation in both new and existing assets;
• Supply by companies with technical support, documentation, and international presence.

In this context, devices based on UV sensors with direct circuit breaker operation (ultrafast trip relay output connected to breaker coil) have become the gold standard in industrial electrical protection.

ZYGGOT^®: Pioneering Ultrafast UV Detection Sensors

Varixx is the world’s first and only manufacturer using dedicated UV sensors for arc flash protection. The ZYGGOT sensor line offers:

• UV-only detection — no need for light transformers or current transformers (CTs);
• Response time under 0.3 ms — the fastest in the industry;
• Robust architecture with easy integration into both new and legacy systems.

In addition, Varixx provides national and international technical support, full documentation, and strict certifications in industrial safety.

Conclusion

The NBR 17227 standard marks a crucial advancement in raising industrial electrical safety standards across Brazil and Latin America. More than a regulatory benchmark, it provides clear directives for mitigating incident energy — one of the greatest risks in today’s industrial environments.

However, the effectiveness of this standard depends directly on the conscious adoption of the right technologies. That’s where systems with UV sensors and ultrafast quenching — like Varixx’s ZYGGOT Arc line — stand out as robust, efficient, and adaptable solutions for both new and existing facilities.

By choosing this technology, your company protects lives, safeguards strategic assets, and ensures operational continuity with an intelligent, fast, and technically superior system — offering excellent cost-effectiveness.

Discover the ZYGGOT Arc family and learn how your facility can become a benchmark in electrical safety with the most advanced arc flash protection technology available.