The shocking effects of an arc flash explosion

Most people tend to respect electrical equipment, but they may not understand the dangers that associated with it. One of those dangers is arc flash. In fact, the likelihood of injury from an arc fault is higher than injury from an electric shock.


Most people tend to respect electrical equipment, but they may not understand the dangers that associated with it. One of those dangers is arc flash. In fact, the likelihood of injury from an arc fault is higher than injury from an electric shock.Understanding more about arc flash, including what causes it and what effects take place when it occurs, helps you to respect and avoid it. Image Courtesy: L&S Electric.

Understanding more about arc flash, including what causes it and what effects take place when it occurs, helps you to respect and avoid it.

What is an Arc Flash?

An arc flash (flash over) is the result of an arc fault and is the visible part of the fault, resulting in heat and light. It occurs when energy is rapidly released and travels from one phase Busbar to another phase Busbar, or from a phase Busbar to the ground. During an arc flash, the air acts as a conductor.

The most common reasons for flash are either human error or a failure of the equipment such as insulation failure, poor maintenance, etc. Arc flash occurs more often when equipment is operational, or there are nearby active repairs. It is not always possible to predict when a flash is going to happen and more than likely, it happens without warning. That is why learning more about arc flash reduces its possibility.

Results of Arc Flash

There are several ways to be injured as a consequence of a flash. Here are a few examples.


One of the most common results of a flash is burns. When it arc flash occurs, the heat reaches more than three times the temperature of the surface of the sun. Although the arc fault that led to the flash burns itself out very quickly, the energy discharge results in a release of energy that burns everything in its path.

Light and Noise

Along with high levels of heat, the light from the flash also damages eyesight. The intense light flash leads to blindness in some cases. The sound of the flash is also enough to cause hearing loss or damage as well.


The force of the explosion knocks a person off of their feet. If they are on a ladder or scaffolding, it causes them to fall. More injury results from the shrapnel associated with the flash.


Another consequence of a flash is poisonous gases. If inhaled, this may lead to lung damages in some cases.

In Sum

Understanding the cause and effect of arc flash helps reduce the possibility of the problem occurring. It is also important to know the danger zones and to wear the appropriate PPE if you are in the area.

Conduct a survey of your facility to determine where those risks exist. These surveys minimize the possibility for a flash or flash injuries.

David Manney, content marketing, L&S Electric. This article originally appeared on L&S Electric's website. L&S Electric is a CFE Media content partner.

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