In its truest sense, Arc Flash Safety is really a combination of things that protect workers and organizations from the destructive force of an electrical arc flash.
The key elements of Arc Flash Safety are procedures, policies, safe work practices, tools, equipment, Arc Flash PPE and engineering solutions.
But the one we are going to zero in on today is arc flash safety procedures.
If you and your organization can master these two procedures, then your chances of experiencing an arc flash will be significantly reduced.
First let’s make sure everyone understands the dangers associated with an Arc Flash.
When an arc flash occurs, it’s because your electrical system has decided to send every last drop of energy it has to a very small part of the system... a part of the system that is nowhere close to being able to handle that much energy.
Things heat up rapidly and explode.
But this is only the beginning. On top of that explosion you are faced with the following dangers:
- extreme heat... upwards of 20,000 degrees C
- a flying plasma ball (a ball of fire)... which will ignite clothing
- a concussive blast if energy
- deafening sound (about 160 dB)
- blinding light
- molten shrapnel
- vaporous gasses
Each one of these would not be something you would want to encounter.
So, let’s talk about how to avoid them.
Arc Flash Safety Procedures
There are two procedures that above all else will dictate the success of an arc flash safety initiative... how to establish an electrically safe work condition and using an energized work permit.
First, we will go over establishing an electrically safe work condition.
This is essentially lock-out-tag-out for electricians.
You start by learning about the system you are working on, where the disconnects are, if there are multiple sources of energy and then move into your regular lock-out.
After operating the disconnect, and visually verifying that all three blades are open (as long as it’s safe to do so) you can move to the most important step.
Verifying absence of voltage with an approved voltage detector.
First check your meter on a known source
(to prove that it works... so maybe a 120-volt receptacle).
Then test each phase-to-phase and phase-to-ground of the circuit... this is extremely important.
Lastly, and only if the equipment permits, install temporary protective grounds. This typically will only be required on high voltage equipment.
Once, you’ve verified that the circuit is properly locked-out, tested for absence of voltage and applied grounds then you’ve basically eliminated the arc flash hazard.
The second procedure is your energized work permit/procedure.
If you cannot de-energize the system to do the work, then you need to take extra precaution and complete the energized work permit.
This will ensure that you’ve spent the extra time thinking about the dangers and how to avoid them. It will also help you think of ways not to perform the work energized (because you’d rather not complete the permit!).
The fundamentals of the energized work permit are understanding the task, performing the risk assessment, deciding on mitigation techniques (most likely PPE), and most importantly justification and approvals.
Why you are doing the work energized is the most important thing to consider... because if you can’t think of a good reason (and because you need to make product doesn’t cut it anymore)... then you shouldn’t be doing the work energized and following the first procedure I laid out to de-energize the system.
The second most important part is the signatures... someone needs to approve the work on energized equipment. So again, if they aren’t buying the justification then the work is not happening energised.
Arc flash Safety is a broad term, but like I said earlier, to give you something you can put in place right now and something I feel is most effective, start with implementing these two procedures.