An arc blast and an arc flash are related, but there is a distinction between the two. What is each one about? How do their dangers differ? Here’s a look at the difference between arc blast and arc flash.
Understanding an arc flash
This occurs due to an electrical failure, which can result in an explosion. Electricity escapes from the system where it is being used and travels through the air to another conductive point. The arc flash can reach temperatures four times the surface of the Sun. This, of course, can cause severe burns to anyone near the area. In addition, metals and other objects can melt or catch fire.
Understanding an arc blast
The arc blast is the shock wave that is created from an arc flash. In many cases, it occurs when a tool or conductive object passes close to electrical conductors. This blast can be extremely powerful, so it can launch all kinds of objects into the air at high speed. Even the pressure itself can result in significant damage to the human brain, organs, and other parts of the body. The event is distinctive by flashes that resemble an explosion. People can also be sent flying, which can lead to impacts with other things nearby. The strength of an arc blast will depend on how powerful the arc flash will be and the amount of pressure created.
When a powerful arc flash occurs, the arc blast will be unavoidable. This combination creates a particularly dangerous situation for those in the area, as well as for the facility where the incident takes place. The arc flash can melt nearby metals, while the arc blast can send them flying. This creates an extremely dangerous environment, so it is important to have a safety plan in place for these situations.
Dangers of an arc flash / arc blast
Here is a list of the different risks posed by these incidents:
- Shrapnel: drops of molten metal are projected at speeds greater than 1.126 km / h, so they can easily penetrate any personal protective equipment.
- Extreme temperatures: Arc flash and arc blasts can generate the highest temperatures ever recorded on Earth, up to 20,000 ° C.
- Sudden air expansion: all known materials vaporize at these temperatures. The rate of expansion is comparable to a piece of copper the size of a pea expanding to the size of a car. The pressure of the impact can throw workers into the air.
- Fatal burns: these can occur even if the worker is several meters away. Clothing can also catch fire if the proper protective equipment is not worn.
- Hearing loss: an arc blast can have a sound magnitude of 140 dB at half a meter away, so the loss of hearing can be permanent.
Recognizing the hazards associated with arc flash and arc blast helps workers understand why the use of personal protective equipment is so important when handling energized electrical equipment. Similarly, knowing the difference between arc flash and arc blast offers the possibility of designing prevention strategies.
Do you know? When an arc flash study is outdated or incomplete, your employees are at risk.