What is an arc flash?

An arc flash is a sustained electrical arc between conductors, often with explosive energy. It is accompanied by a bright flash of light, flying shards, a pressure wave and toxic copper fumes.

Other types of arc flashes exist: welders, for example, use small, controlled arc flashes. In the case of solar panel connectors, a (small) arc may also be caused by poor contact, leading to fire and damage.

No electrical installation can be guaranteed to function without the risk of arc flashes. HyTEPS offers the possibility to gain insight into this by means of measurements. Let us first define exactly what kind of arc flashes occur in electrical installations, and then examine the causes and consequences.

Characteristics of an arc flash

  • Extreme temperatures of more than 19,000 degrees Celsius
  • Flying (heated or molten) shards of the installation
  • A pressure wave with a deafening blast
  • An intensely bright light, in both the visible and invisible spectrum (infrared)

The risks to your employees

  • External burns
  • Internal burns as a result of inhaling ionised gases
  • Blindness (temporary or permanent)
  • Physical injury due to the pressure wave
  • (Permanent) hearing damage
  • Copper poisoning (inhaled copper gases coagulate in the lungs, leaving a permanent copper residue)

Most common causes of arc flashes

Most arc flashes are caused by human error, such as dropping conductive tools.
Bridging of conductors by rodents can also lead to arcs resulting in damage to the distributor and failure.

What is the difference between a short circuit and an arc flash?

A short circuit causes an arc flash. If the source of the short circuit (e.g. a tool used during maintenance) is removed, the arc flash may continue to exist. This is because an arc flash ionises the air: a section of conductive air is created, like a lightning bolt. Only when the supply of current is interrupted, for example by a fuse or the melting of a cable, will the arc flash cease.

The risk of arc flashes is often even greater in direct current installations than in alternating current installations. The impact of an arc flash will also be much greater. This is because with direct current the voltage does not ‘pass through zero'.

Arc flashes can cause serious injuries such as burns, blindness and copper poisoning and are also a threat to business continuity. With arc simulations HyTEPS can help you understand the risks, increase knowledge of your installation, and take effective action. 

Take a look at our arc flash cases!

Be aware. Choose safety.

HyTEPS is expert in the prevention of arc flashes

Scroll to Top