Worker protected from arc flash by energy shield.

Arc Flash: The Silent Workplace Hazard and How to Tame It

Soraya Malik in Tech & Innovation August 2025 • 5 min read.

"Protecting your personnel and equipment with cutting-edge arc flash mitigation techniques in low-voltage environments"

In the realm of workplace safety, electrical hazards loom large, with arc flash incidents being a particularly grave concern. Arc flash is a dangerous electrical explosion that can occur when a fault in an electrical system creates an arc of intense heat and energy. These events can result in severe burns, equipment damage, and even fatalities. As awareness of these dangers grows, so does the demand for effective mitigation strategies.

The National Electric Code (NEC) has taken note of this growing concern, introducing requirements in section 240.87 to reduce clearing times of overcurrent protective devices. This focuses on systems with a continuous current rating of 1200A or higher. One of the key methods highlighted by the NEC is the use of energy-reducing arc flash mitigation systems. These systems are designed to minimize the energy released during an arc flash event, thereby reducing the potential for harm.

This article delves into the world of arc flash mitigation, exploring the innovative technologies and strategies that are revolutionizing electrical safety. We'll break down the complexities of these systems, making them accessible and understandable for a broad audience, including those who may not have a deep technical background. By the end, you'll have a clearer understanding of how to protect your personnel and equipment from the devastating effects of arc flash.

What are Energy-Reducing Active Arc Flash Mitigation Systems?

Worker protected from arc flash by energy shield.

Traditional methods for mitigating arc flash hazards often rely on the clearing time of upstream overcurrent protective devices, such as circuit breakers. However, these devices have a limiting factor: their clearing time. Power circuit breakers, for instance, can take as long as 4 cycles (approximately 67 milliseconds) to clear a fault. In high-fault current systems, this delay can be too long to adequately reduce incident energy. High incident energy events often lead to equipment damage and can cause burn injuries requiring personal protective equipment (PPE).

Arc flash relays represent a step forward, sending a trip signal to the upstream circuit breaker to expedite the clearing process. However, the most advanced systems circumvent the limitations of traditional circuit breakers altogether. These innovative systems, as defined by the UL Standard for Arcing Fault Quenching Equipment, create a lower impedance current path to transfer the arcing fault to a controlled compartment. This rapid transfer significantly reduces the duration of the arc flash, minimizing incident energy.

Zone-Selective Interlocking
Differential Relaying
Energy-Reducing Maintenance Switching with Local Status Indicator
Energy-Reducing Active Arc Flash Mitigation System
An instantaneous trip setting that is less than the available arcing current
An instantaneous override that is less than the available arcing current
An approved equivalent means

These arc quenching systems come in two primary flavors: those that apply a bolted fault to create a low-impedance path and those that create a controlled arcing fault. Bolted fault systems, while effective, can subject upstream equipment to maximum peak fault currents, potentially causing damage. The latest systems generate a controlled arcing fault path, offering a lower impedance than the original arcing fault but a higher impedance than a bolted fault. This approach still transfers the arc to a controlled compartment but reduces stress on upstream equipment while maintaining effective incident energy reduction. These cutting-edge systems are called current limiting arc quenching devices.

The Future of Arc Flash Safety

As industries continue to prioritize personnel safety and equipment protection, the demand for effective arc flash mitigation strategies will only increase. Current limiting arc quenching devices represent a significant leap forward in arc flash safety, offering superior personnel protection, advanced equipment protection, and reduced downtime. By understanding the principles behind these technologies and implementing them in your facilities, you can create a safer and more productive work environment.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1109/ppic.2018.8502185, Alternate LINK

Title: Current Limiting Arc Flash Quenching System For Improved Incident Energy Reduction

Journal: 2018 IEEE IAS Pulp, Paper and Forest Industries Conference (PPFIC)

Publisher: IEEE

Authors: Robert J. Burns, Adams D. Baker, Dan E. Hrncir

Published: 2018-06-01

Everything You Need To Know

What is an arc flash and why is it a hazard in the workplace?

An arc flash is a dangerous electrical explosion caused by a fault in an electrical system. It releases intense heat and energy, posing a significant risk of severe burns, equipment damage, and even fatalities. The danger stems from the extreme heat and pressure generated, which can cause severe injuries to personnel and substantial damage to equipment. The potential for such incidents underscores the critical need for effective mitigation strategies in industrial settings.

How do Energy-Reducing Active Arc Flash Mitigation Systems work to protect personnel and equipment?

Energy-Reducing Active Arc Flash Mitigation Systems aim to minimize the energy released during an arc flash event. Unlike traditional methods that rely on the clearing time of overcurrent protective devices, these systems employ innovative technologies. They create a lower impedance current path to transfer the arcing fault to a controlled compartment. This rapid transfer significantly reduces the duration of the arc flash, thereby minimizing incident energy and the potential for harm to both personnel and equipment. These advanced systems include current limiting arc quenching devices.

What are the limitations of traditional methods like circuit breakers in arc flash mitigation?

Traditional methods, such as relying solely on circuit breakers, have limitations due to the clearing time of these devices. Circuit breakers can take approximately 4 cycles (about 67 milliseconds) to clear a fault. In high-fault current systems, this delay can be too long, resulting in high incident energy events that can cause equipment damage and lead to burn injuries. This limitation highlights the need for faster-acting mitigation systems to reduce the duration and intensity of arc flashes.

Can you explain the difference between Bolted fault systems and current limiting arc quenching devices?

Bolted fault systems create a low-impedance path by applying a bolted fault, which can subject upstream equipment to maximum peak fault currents, potentially causing damage. In contrast, current limiting arc quenching devices generate a controlled arcing fault path, offering a lower impedance than the original arcing fault but a higher impedance than a bolted fault. This approach still transfers the arc to a controlled compartment but reduces stress on upstream equipment while maintaining effective incident energy reduction. These devices represent a significant advancement in arc flash safety.

What role does the National Electric Code (NEC) play in arc flash safety, and what specific requirements are relevant?

The National Electric Code (NEC) addresses arc flash safety by introducing requirements, such as those in section 240.87, to reduce clearing times of overcurrent protective devices. This is particularly focused on systems with a continuous current rating of 1200A or higher. The NEC emphasizes the use of energy-reducing arc flash mitigation systems to minimize the energy released during an arc flash event. This code underscores the importance of implementing advanced technologies to protect personnel and equipment from the devastating effects of arc flash incidents. Various methods are highlighted, including Zone-Selective Interlocking, Differential Relaying, and Energy-Reducing Active Arc Flash Mitigation Systems.