Arc Flash Labeling
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Hi. I'm Jill, chief safety officer with Vivid Learning Systems. I'm a former OSHA inspector and I'm here to help you identify and correct workplace safety hazards. For this series, we're at Southern Minnesota Beet Sugar Cooperative in the heart of the upper Midwest to show you, no matter where you work, safety training is for everyone.
There are some of us who see arc flash labels or stickers on electrical panels and devices and think, "Great. I'll get some of those stickers, I'll out them on a panel or the device, and we're good. Our employees will know what level of arc-rated clothing they'll need to wear and which insulated tools they'll need," except it's really not that simple. There's a science behind those labels.
Today, we're lucky enough to have with us Jason who is president of EPSCO, an electrical engineering firm who specializes in electrical safety. Jason, before one of those stickers can go on a device, what do people need to know? What's the process? It's not just simple. You don't just go print out a bunch of stickers and go stick them on things.
That's absolutely correct. Thanks, Jill.
There's really a lot of misunderstandings behind arc flash and what it takes to get the labels on the equipment. Really, the label itself is designed to look simple and be usable just for the people.
For the end-user.
For the end-user who are using it, exactly.
The process to get it on starts ... It takes us six weeks to two to three months to get through the process to get this label on the equipment.
We start with the utility company. We go there and we collect bolted fault current information.
Okay. That information, when you start doing that, that's with ... Electrical engineers do that kind of work, right?
That's correct. That's correct.
Usually, it's one of two things. Sometimes we get a calculated value on the line side of the transformer. Other times, we get an infinite bus calculation. A lot of jargon there. It's just very complicated information to give us the amount of power that's available at the primary incoming feeds for that company.
Okay, so that's where it starts, the incoming feed.
Then what? Take us through the process.
Absolutely. That's maybe the easier part of it, is collecting that information.
From there, we'll start the data collection process. We start at the utility transformer, and then we will create a schematic or a drawing down to each device in the facility, whether that's a 480 volt panel, a 480 volt motor control center, things like that. We have to collect the information from that utility all the way down to those devices.
For example, breaker information, we need to collect all that so we know just how long that fault is allowed to exist or propagate in that area.
Cables play a very large role because we need to know how much fault current is being let through this service to get to this panel. There's a lot of information that we need to collect all the way down to whether the conduit is magnetic or not, if they [inaudible 00:03:01] collect information.
Mm-hmm (affirmative). Right.
It's a long process. It's conducted in our group by electrical engineers who are certified to open up panels, collect information. Really, they are tracing conduit through your entire facility to each device where a label gets put.
It's almost like a genealogy study. You go back to the source of the family and you're following this tree to all of these family members. If a company ... What would be the average number of maybe devices when you're doing that work that a company may have, that you're trying to track from that source back to that device?
That's a wonderful question. We get that question a lot. It's very dependent on the size of your facility. You can go ... We've got algorithms, we can do square footage calculations based on it.
A smaller facility, you might see anywhere from 10 to 20 labels, depending on what they have. We have facilities where we'll put on 2,500, 3,000 labels, things like that.
Wow. When you talk about the process can take two to three months, that's why.
Because you're going down to each individual device.
That's correct. That's correct. That's within the data collection phase.
Once we've collected this information, we then put it into a very powerful software model that does the calculations for us. It takes into account the bolted fault current. It can create an arcing fault current level based on that, and then it will look at what the voltage is present, library files for the protected devices feeding it. There's a lot of information that goes into calculating how much power is available here and how long that arc can propagate for during the event.
Sure. The purpose and point of having that label is for the person who is going to open that panel to know what level of protection they need, correct?
Absolutely. Absolutely. If you have a technician walk up to a panel like this, they're going to start by reading through it kind of line for line. They should start to make sure that the label corresponds with the working location.
To the right spot, okay.
Exactly. Then, there's two main pieces of information we're looking for here for them.
They're going to be looking at the shock-related information. This is what rubber gloves they have to wear, where they should be setting up boundaries, things like that. In a room like this, they may boundary off the whole motor control center room before they even walk into it. That's probably the most common.
They go through, the calculate the shock value or the shock hazard.
They'll then take a look at the incident energy calculation. The incident energy calculation is going to correspond with PPE. They see eight calories per centimeter squared at minimum arc rating here. Then, as they suit up, either they are already wearing a shirt like mine that is rated for eight to 12 calories per centimeter squared or they're having to put on a suit that is rated at that level. With something like this, you'll see that we need a balaclava, arc-rated face shield, safety glasses, hearing protection. Everything is outlined in the label.
Everything they need.
Absolutely. That should be how it is. Maybe it's not a requirement for the code, but that's probably the simplest way to do it.
Sure. Regardless ... Is it regardless of the type of work they're going to do at that panel? They need to follow that label every single time?
Oh, man. That's a great question. We get that question a lot.
The short answer is yes.
The most common way we get that question is, if I'm operating this MCC, this device, do I need to be wearing the arc flash PPE listed on the label? Your quick answer is going to be yes.
There is a set of exclusions that would allow you to operate equipment like this not wearing the arc flash PPE as long as the equipment was properly installed, properly maintained, doors on, covers closed, there's no signs of imminent failure. You do have a couple of caveats in it that would allow you to operate equipment like this but, depending on the age of the equipment, depending on how often it does get operated, our general rule of thumb is, if you're going to be operating this equipment, you're going to be opening the panel cover most likely anyways...
Follow the label.
Follow it. Suit up for the operation.
You can wear that same PPE most cases for the troubleshooting aspect, for the voltage measurements, for verifying the equipment is opened, everything.
Sure. Makes sense.
If a company is thinking, "Wow, we haven't done that. We haven't done this whole analysis to find out if we have the right labels," or, "We haven't done this process at all," your firm specializes in it. You're an electrical engineering firm that specializes in electrical safety. If someone is listening to this and thinking, "How would I go about finding or hiring," what would they start searching for? What are some tips to get them to the right sort of service that can help them?
That's a really good question. There's a lot of groups that are performing arc flash studies nationwide right now. Your most common groups are either major equipment manufacturers or electrical contractors.
There's a couple of groups like us that are engineering firms that don't offer outside services, we just kind of specialize in electrical safety. A good starting point is to engage someone. They will kind of guide you through the process. Generally, what we do is, once we're engaged to perform an arc flash study, we'll give you guys forms where we'll either come on site or we'll give you a form that you're able to just collect how much information you have.
Usually, once that information is collected, you can then submit that for a proposal through that group.
A lot of groups are comfortable with you taking that same information and submitting it to multiple bidders.
There's a couple of things that I caution you on. Since a lot of people are in the infancy stages of starting an arc flash study right now, there's a couple things that get missed. There's a couple considerations. One, make sure that you've got a plan on the back half of the study with updates and changes.
So if ... Yeah, if something changes or you have an addition or you're moving things around, what's the step?
Absolutely. What happens next?
What happens next?
You want to keep that into account, just because, as you make changes, you need to do the past job you can to update that study.
Mm-hmm (affirmative). Makes sense.
The other thing is make sure that there's a registered PE. We at least recommend a registered PE for the state in which the study is performed.
Okay. A registered professional engineer.
Correct, registered professional engineer.
Okay. Very good.
That's great. Absolutely.
The term that people are looking for is arc flash study, is that the vernacular you used?
So they're asking for that, okay.
That's probably the most common phrase that we get.
Power systems analysis is what we call it because, a lot of times, you get other information.
You'll get a schematic, protected device coordination, short circuit ratings, equipment ratings.
Depending on which version you go with, there's 15 to 25 deliverables that really ... You get the compliance of the arc flash study piece but you also get some production protected type items with it.
Sure, some extra pieces.
When a company is going to start choosing their arc-rated clothing, what are some maybe tips on ... What's the vernacular with that, while they're looking for that, as well?
That's a really good question, especially after 2018, as far as how do we select the PPE or PPE vendor, if I understand you correctly.
Mm-hmm (affirmative). And tools, too.
Yeah. Okay. Yes.
Absolutely. Having a good understanding of what's in your facility is key. A facility like this has low voltage and medium voltage, so we need to be very conscious on making sure our low voltage, class 00, 500 volt-rated gloves are ending up in the correct locations, and that our 4160, our 5KB, our larger medium voltage gloves are ending up in that spot.
And they're accessible to the employees that need them.
And that they've been trained on how to put them on?
And how to test them? Because there's ... You want to make sure that especially your rubber gloves don't have any holes in them, right?
There's a really important training component that goes along with that, as well.
Very much so. Absolutely.
Yeah. Great. Jason, is there anything else you'd like to share with our audience about arc flash studies, things, tips maybe that people should keep in mind beyond what you've already talked about, or with the clothing in general?
You bet. You bet. I would say, when you engage an arc flash study, make sure that you go at it from having the ends in mind from the beginning. Keep in mind who the vendor is as you go into the process to make sure that they have experience with power systems like yours.
You're forming a partnership with them.
Very much so, yes.
Very much so. They're going to be able to make recommendations. Once they go through your facility, there's a lot of things that they'll know about your facility that you didn't know before they got there.
Right. They're going to be discovering things.
You want to make sure that they care enough to recognize those things, and that they'll say, "Hey, you may have an issue here with this. They're opening this panel door, it's near some grinding equipment, this is possible failure. Let's look at it."
Yeah. Sure. Sure.
A lot of things like that.
Help you kind of triage, maybe, your approach?
If we need to step it out over time.
Yeah. That's wonderful.
It's a lot to bite off [inaudible 00:11:42] take it in chunks, it's [inaudible 00:11:42].
Yeah. Wonderful. Thank you so much for the information you've provided today.
You bet. You bet. Thanks for having me, Jill.
Mm-hmm (affirmative). Hopefully, this helps those of you who are listening if you're in the process of beginning an arc flash study in your facility.
I hope you gained a safety training skill today. If you know someone who needs this, go ahead and pass it on. Safety is everyone's business.