When in the workplace or completing home improvement, there is always the need to know safety precautions, especially when dealing with electrical components. One phenomenon called arc flash can be extremely volatile when experienced, therefore it is sensible to understand what it is, what can it do and ways to prevent it from happening.
An electric arc is described as ‘a luminous bridge bridge formed in a gap between two electrodes’. Simply put, an arc flash is when a fault or short circuit occurs which passes through this gap. Arc flash is a visible electric flash across this gap which happens when the electric current’s path diverts off course. The energy dissipated can turn into an arc blast if left long enough.
What can happen?
The deadly energy released from an arc flash event can cause ionization of the air which can create temperatures upwards of 35000 degrees Fahrenheit. This type of reaction can caused severe burning, which can destroy the skin in a fraction of a second. Burns relating from an arc flash can be caused even by a significant distance from the actual event, meaning those unprepared within the surrounding area can be affected. The ionization of the air can create a fire which can easily spread throughout a building or home, causing severe damage. Metal components, from the high temperatures, can change from solid to vapor resulting in explosive pressure. This can create flying objects, often molten metal, which can cause damage to anyone it hits. The pressure waves and sound blast created from these changes can also result in the eardrums being affected, meaning some people suffer from temporary or permanent hearing loss.
What causes an arc flash?
An arc flash can be caused by various hazards in the area, these could be:
- Dust in the area where electrical conductors are being placed
- Dropping tools- the material of the tool and the electrical plug can act as a conduit which can cause the fault in an arc flash
- Accidental touching of conductors can release the energy necessitated for an arc flash
- Condensation as always can create unsafe environements when dealing with electricity
- Material failure- wires, conductors that have faults in them can cause the arc flash
- Faulty installation- human error can always be an issue, any electrical installations with faulty cables or connectors can lead to faults
There are a few ways which everyone can protect their environment and try to discourage the circumstances needed for an arc flash. De-energizing the circuits in the area can nullify the electrical current that may cause any faults. If anyone suspects there may be a flaw in the system, this may be the best solution until all circuits are checked. Work practices may need to be changed to ensure that all employees are aware of the dangers involved with any problems in the workplace. Guarding and barricades being placed around the electrical area may be used to ensure there is some way to protect workers if an arc flash does occur. Personal protective equipment for employees working within electrical environments can help to ensure all workers are somewhat protected from the high temperatures involved in an arc flash. Applying grounding devices where stored energy could exist can help to prevent any electrical disturbances.
There is a checklist which can be given to all employees working in electrical environments to make sure all protective cautions are taken. This checklist can include:
- Are all persons trained in shock hazards?
- Do all persons have access to protective equipment?
- All persons have easy access to a one line diagram?
- Written safety precautions have been taken?
- Equipment is grounded and tested?
- Recent relays have been calibrated?
Overall, an arc flash is a dangerous occurrence which can have devastating consequences if the proper precautions have not taken place. Therefore, anyone dealing with electrical equipment needs to be aware of what an arc flash actually is, the dangers of one and how to prevent them.