Arc Flash Protection
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Join HSI Chief Safety Officer Jill James as she visits environmental health and safety professionals in their workplaces to explore important workplace safety topics. This video covers what an arc flash is, how to read arc flash labels, and what kind of fire retardant personal protective equipment (PPE) to wear.
Hi I'm Jill, Chief Safety Officer with HSI. I'm a former OSHA inspector and I'm here to help you identify and correct workplace hazards.
For this series, we are at the beautiful Monterey Bay Aquarium to show you that no matter where you work, safety training is for everyone.
Not long ago I was talking with an electrician and I asked him if he had ever experienced an arc flash. Now an arc flash is an electrical explosion that can happen in an electrical device where the metal inside of the cabinet vaporizes and blasts out at the panel at a person.
This particular electrician told me he had experience in arc flash personally. He was working to install new electrical devices in a in a building and he said he was a just about at the point where he was going to energize the entire system and he was thinking about the fire rated clothing that he had access to and was remembering most of his FR rated gear was back at his truck and he thought well this is a new installation and it's not likely to have an arc flash occur here and he was already wearing his fire rated shirt and so decided not to make the effort to go back to his truck to get his fire rated clothing and so when he energized the system what he didn't know was that there was a dust in the panel from the manufacturing process and an arc flash occurred at that time. Luckily he wasn't standing with his body directly in front of the panel, and so he didn't sustain the majority of the blast and wasn't injured badly.
And so even when you have new installations arc flash can still happen. So how do you know how to protect yourself? What is the right fire rated clothing to wear? Well the only way to know that is by doing an arc flash hazard assessment and that needs to be done by a qualified person. It's an engineering method that starts with where the power comes into your community and traces it right back to the exact device that you're going to be working with and then you can have the proper labels applied to know what the particular fire rate of clothing that your employees need to be wearing.
Today we're at the Monterey Bay Aquarium and I'm with a safety manager from the aquarium Jeremiah and they have done that electrical our clutch assessment and they have applied their labels and Jeremiah maybe you could walk us through that that process and the labeling and how you make it work here at the aquarium.
First and foremost one of the most important things that these areas are kept clean you don't want this to turn into an auxilary storage area where you would have mop buckets, boxes anything like that. Particularly in the event of emergency you want to be able to access your panels. You also want to restrict access from unauthorized personnel. Really these are serious work areas where only people that are qualified to do so should access.
So let's look at a label real quick. If you look to Jill's right here you can see at the top there's a category and that category is part of the reading system and if you read the label it will tell you what type of personal protective equipment you need for that category. We have several different categories here with different examples, but look back here we've got a category one they'll tell you you need a flame-retardant shirt and pants it'll also tell you you need gloves we've got some examples of some of the flame-retardant equipment that you might be required to use to access some of these panels.
This is an example of a face shield now if you were to access one of these panels that was energized and it was required this would protect your face, neck and a head from an arc flash.
Now we also have an example of a flame retardant jacket. Now you would wear this as well with pants. You may be required, like on some of the other label if you see to wear coveralls over this but what I want you to notice is that it has a rating on it. This is a unit of measure. Its calories per square centimeters and this protects up to 11 calories per square centimeters. If you look off to my right you can actually see this label says up to ten calories per square centimeter actually if you look off to the right where Jill has this one is up to 11 which this would protect but the panel just adjacent to that one says 12 calories per square centimeter. So this jacket would not be sufficient to access that panel.
So it's really important that you get training on this if you're an electrician you're going to be accessing these areas or if you're a supervisor and you're gonna walk through an MCC room or any any other area where you have these electrical panels that you know when you understand these rules and especially if you're a certified electrician you need to be able to interpret the rule so that you know that when you access that panel and you're doing it safely.
Now here at the aquarium we have several different panels rating from all different categories. Category 0 all the way up to panels that we can't open at any energized point and that scenario would have to actually get the utility company to kill power to the transformer so that we could access those panels, so that would be a best practice. That's definitely something I would recommend and try to avoid accessing these panels when they're energized whenever you can.
Jeremiah thank you so much for sharing your knowledge with us today. I know that this can be really complicated so if you're looking for help with doing that our clutch hazard assessment let us know we can connect you with some resources.
I hope you gained a safety skill today. If you know someone who needs this go ahead and pass it on.
Safety is everyone's business.