Arc flash explosions are a serious hazard to anybody who works with electrical
systems; this is a fact. With anything between 5 and 10 injuries per day in America
alone, you need to be aware of the dangers and precautions you and your workers
should be taking to negate or severely reduce the risks involved.
Arc blasts and arc flashes, as they’re more commonly known, are explosive
electrical arcs created by a short circuit from one live conductor to another or to
ground. Within 1/1000 of a second, the surrounding area temperature can increase to
anything up to 35,000 degrees. This sudden heat surge blasts molten metal and debris
outwards, causing further damage to the surrounding area.
The lists of potential injuries due to arc flash are as dreadful as they are varied, and
not limited to individuals working next to the blast. Anyone within a 10 to 15 feet
radius is in danger of serious burns through heat exposure and the incorrect protective
clothing catching fire. Anyone caught within this vicinity is at risk of hearing damage
due to blast sounds reaching anything up to 160 dB. Damage to sight is also possible,
caused by the UV light emitted by vaporised metals. Of major concern are the flying
shrapnel and molten metal emitted by the blast. This can travel far and cause massive
damage to anyone within its vicinity and cause further problems with lungs when
vaporised metal is inhaled. Concussive damage from blasts equivalent to several
sticks of dynamite can cause memory loss and further neurological damage and
impacts caused by falls and collisions from equipment can be fatal.
To reduce the risk of arc flash occurring, equipment should be de-energised before
work is carried out. De-energising is not always practical or even possible, and
sometimes a cause of arc flashes in itself. There are solutions out there that allow
workers to operate, maintain and check equipment remotely, but they are not available
to all and can be expensive. If it is entirely necessary to work with live equipment,
you should adhere to the regulations and rules outlined in the NFPA 70E Standard for
Electrical Safety in the Workplace, available on the National Fire Protection
The NFPA 70E will help you to calculate the hazards and requirements needed for
your workplace, and determine what areas need to be concentrated on. Professional
arc flash analysis is available to outsource and is recommended, as are the proper
labels and notices. It will also give you information on the proper level of PPE
required for the equipment you work with.
The proper PPE is something that cannot be ignored. Although it doesn’t negate
injury due to arc flash, it does reduce the risks of fatalities and serious, life threatening
and altering burns, something no one wants in the work place.
You need to be aware of the risks of arc flash. Not only can it cause damage and cost
to your electrical equipment, but to the health and safety of anybody working on it.
Your number one aim should always be to make sure you are safe and secure and
aware of the dangers of arc flash.
The author of this article works for a company that specialises in Arc Flash PPE ,
Arc Flash Clothing and Arc Flash Protection.