"An Arc Flash is caused by an accidental short circuit in an electrical phase, either from phase to ground or phase to phase. An Arc Flash is an explosion of oxygen in the air around the phase(s), which creates a really high temperature; enough to melt conductors and other electrical parts. In turn causes an extremely loud bang as the explosion takes place".
When working on or near electrical equipment you need to become familiar with the hazards associated with that particular work. You may already have a good understanding of shock hazard but what about arc flash?
First, we need to get our terminology right.
We need to focus on arc flash hazards more than arc flash events... this is because one of the fundamentals of a good safety program is identifying hazards.
If you are focused on the “event” then it’s already too late... the arc flash has happened.
An Arc Flash Hazard is defined as:
“A source of possible injury or damage to health associated with the release of energy caused by an electric arc.”
That’s a nice definition but it doesn’t really tell us much.
What you need to take away from this is that an arc flash hazard is any piece of electrical equipment that has the potential to violently explode, sending insane amounts of heat, plasma, light, shrapnel, vapor, shock waves, and molten metal shards in the direction of anyone working close by.
That sounds a lot scarier than a release of energy.
And you are probably going to want take a lot of steps to protect you and your team from it.
What causes an Arc Flash
An Arc Flash is caused when something obstructs the normal flow of electricity and creates an arc through the air between two phases or from phase to ground...For those of you who are not up on your electricity terms, picture a bird stretching its wings across two of the power lines... a massive lighting bolt shooting through the bird from line to line... which then leads to an explosion.
Take that same concept and apply it to the motor starter that runs a 30 hp pump in your facility. Except this time, instead of a bird, it’s a mouse, water infiltration, corrosion, dust, loose parts, a tool, a digital multimeter, or your hand...
That’s what causes an arc flash.
What is Arc Flash PPE
Of all the hazards I listed above there are two that we really focus on when it comes to protecting ourselves from an arc flash hazard.
Heat and fire (which is more heat really) ... but let me explain the difference.
When an arc flash explodes it creates an amazing amount of heat energy... this is what we call “incident energy”.
Incident energy effects the human body a lot like a sunburn... except it would be similar to getting a sunburn while standing on the sun! Arc flash PPE is specially designed to absorb this heat energy and protect your body.
There is also a plasma ball or fire ball that you will be exposed too. If this went unchecked, you might not get the sun burn but you would still be on fire... which in turn will burn you. So, Arc Flash PPE is also designed so that it will not catch fire.
A typical set of Arc Flash Clothing will cover your body head to toe and include:
Find out how to choose Arc Flash PPE for you and your team here.
This clothing is your most effective protection from an arc flash hazard once the event has occurred. However there are also different types of Arc Flash Clothing:
Treated and Inherent.
What is Arc Flash Safety
Arc flash safety is the strategy that you and your organization use to protect everyone from all arc flash hazards.
Typically, you will want to take this one step further and create an electrical safety program.
This will take into account the hierarchy of risk control methods that are laid out as follows:
- Engineering controls
- Administrative controls
- Arc Flash PPE
Your program needs to cover each of these layers in order to be truly effective.
What is Arc Flash Training
Arc flash training is one of the most effective ways to educate your team on the dangers of arc flash hazards.
Ultimately you want to make sure you understand what the hazards are, what they can do to you if you were exposed to them, what scenarios you could encounter in your workplace, and how to mitigate these hazards so you don’t get hurt.