Arc flash incidents pose significant risks in high voltage environments, hence making proper protection essential for safety and system reliability. This article explores what an arc flash is, its causes, examples in the workplace, as well as protection requirements.
What is Arc Flash
Arc flash or flashover refers to a high discharge of current in the atmosphere around the electric circuit. When the current loses insulation and is exposed to the environment, electrical energy causes the ionization of air atoms. As a result, there is a bursting of heat, light, and pressure with temperatures getting as high as 20,000°F.
An arc flash forms when electrical current jumps across a gap in atmospheric air. Higher voltages can bridge larger gaps, creating a long-lasting arc explosion. In lab tests, voltages below 208V in three-phase AC systems can initiate arcs but struggle to sustain. However, high-voltage systems easily sustain arcs.
You can consider arc flash as plasma streams that are extremely hot and harm equipment, surrounding setup, people, and even civil structures. According to the National Fire Protection Association (NFPA), approximately 400 fatalities occur annually due to arc flash-related accidents in the US. Therefore, you need to consider extensive protection measures against arc flashes in high-voltage applications.
Causes of Arc Flash
If you look at the mechanism of arc flash, insulation breaks and circuit failures are the major causes behind this. Meanwhile, environmental factors, human errors, and poor maintenance can also lead to an explosion of arc flashes.
- Insulation Breakdown: The protective coating on wires or conductors deteriorates due to age, heat, or physical damage. This exposes the live parts to the atmosphere, hence increasing the risk of arc flashes. Often, a poor maintenance culture is the key reason behind insulation breakdown. Because if preventive maintenance is in place, there will be early detection of insulation breakdown.
- Equipment or System Failure: One of the leading causes is the failure of the equipment or electrical system. This could be due to malfunctioning of circuit breakers, relays, or switches that allow for excessive current flow. Sometimes, their incorrect installation and operation also trigger the arc flashes.
- Environmental Factors: The contamination or buildup of dust, debris, corrosion, moisture, vapor, and even animal or insect contact facilitates the route for arc flash in an electrical network.
- Human Error: Operators and engineers might wire the connections loosely or wrongly due to human error. In addition, unintentional touches to energized circuits can also trigger the flashes.
- Use of Low-Quality Instruments: The quality of both the system’s components and calibrating instruments matters in any electrical distribution network. Use of low-quality circuit breakers, arc-resistant units, control panels, and wiring accessories leads to malfunctioning and further risk of arc flash explosion.
Arc Flash Examples
Arc flash protection is necessary, especially in high voltage applications because they are prone to arcing incidents. This occurs in a variety of industries, with the following table highlighting examples of these incidents, their cause, and likely consequences.
| Incident | Cause | Consequence |
| Industrial Plant Explosion | Uninsulated tool on a live panel resulting in a short circuit | Severe burns, fire, equipment damage |
| Utility Worker Injury | Contact with an energized conductor during repairs | Second- and third-degree burns |
| Data Center Arc Flash | Dust accumulation creating a conductive path | Power outage, server damage, data loss |
| Manufacturing Facility Fire | Loose circuit breaker connection caused overheating | Fire, panel destruction, production halt |
| Hospital Electrical Fire | Aging electrical panel resulting in insulation degradation | Fire, patient evacuation, operational disruption |
| Construction Site Accident | Drilling into a live electrical conduit | Severe burns, temporary blindness |
| Oil Refinery Explosion | Lightning-induced voltage spike caused an arc flash | Explosion, injuries, refinery damage |
Arc Flash Protection Requirements
Before implementing the arc flash protection measures, it is essential to conduct an arc flash risk assessment in the facility. Several industry standards provide guidance such as the IEEE 1584-2018. This assessment involves gathering electrical data (e.g., voltage levels, current levels, protection setting, and electrical configuration) and then calculating protection boundaries and potential hazards.
The assessment itself emphasizes the distribution of findings among workers and training them accordingly.
Now, let’s look at the five key protection requirements;
Labeling of Protection Boundaries
In electrical systems or facilities, you must specify the limited approach, restricted approach, and flash boundaries. So, the engineers and workers will know about hazardous zones while working.
Personal Protective Equipment (PPE)
Another strict requirement is an arrangement of appropriate PPE for all workers on the basis of risk assessment and safety standards. This includes flame-resistant (FR) clothing, face shields, gloves, and helmets with ratings for the specific hazard level.
Implementation of Safety Protocols
Follow the safety protocols, such as lockout/tagout (LOTO) procedures to de-energize equipment before maintenance or repair. These protocols ensure that workers are not exposed to live electrical parts.
Training and Safety Programs
Workers must receive regular training on arc flash hazards, safe work practices, and emergency response procedures. It helps employees understand how to use PPE, interpret arc flash labels, and follow safety protocols.
High-Quality Components and Regular Maintenance
Almost 30 % of arc flash incidents are related to equipment failure due to the use of low-quality components in electrical systems and lack of regular maintenance. So, use circuit breakers, fuses, and insulation that have designs capable of withstanding potential risks. Their installation must comply with NFPA-70 codes. Consequently, ensure effective periodic maintenance and response plans.
Arc Flash Protection with Paradigm Controls
At Paradigm Controls, our Engineering Services encompass drafting, design, and oversight for customers. By trusting us, you can be certain of an optimal design for your power system with maximum consideration for functionality, reliability, and enhanced safety with arc flash protection for low, medium, and high voltage applications. We make your role in the buildout as simple as possible. Contact us today and we will partner with you in both existing and new projects.
