HVAC school introduces the anatomy of electrocution, arc flash and an intro to PPE and lockout/tagout. Featuring Bryan Orr.
Read all the tech tips, take the quizzes
and find our handy calculators at https://www.hvacrschool.com/

All right, so I wanted to do a quick video on Electrical Safety. Its safety is something that's extremely important and obviously you know we're speaking to people who, already in the trade or in trade school, and you know you need to get your safety training elsewhere for sure we're not a official OSHA training facility or anything. But I wanted to discover some basic some undisputed facts about Electrical Safety that you should know your training manager, something at a company. You can share this with your staff to just help get their mind in the game with electrical safety, so I'm gon na do another.

Video particularly showing how to use a meter in a safe manner some of the features of meter, but this is just general conversation we're never about the anatomy of electrocution so, specifically how you get electrocuted, which is killed from electricity arc. Flash gear, PPE, lockout, tagout, fall risk grounding and bonding GFC and AFCI and NFPA 70e, the good old National Electrical Code, so we'll just go over this real quick first is the anatomy of electrocution. So there's a lot of things that that make a difference. As far as, if you're going to be killed, and it a lot of it has to do with which direction it passes through your body.

So if it goes, you know through your head and down through your foot here, that's very dangerous because it's traveling all the way down your spine and through your brain and also across your heart. So that's dangerous arm. The arm is dangerous because from an arm to arm path, travels across your heart or very nearby path is very important, but one thing that a lot of technicians say it's kind of silly is they'll say that it's not the voltage that kills you it's the amperage And while there is definitely truth to that, when we're talking about working on high-voltage electrical systems that are connected all the way back to the main distribution panel back to the transformer out of the street, you have nearly an unlimited source of amperage. You know if you get hit with a Taser, it's true that you can get hit with very high voltages and not be injured.

But that's because, if you're hit with the Taser, the Taser is amperage limited. So it's a high voltage, but it limits the amperage. There's only so much amperage can travel through, but our bodies are a very resistive path. If you ever took a meter and measured between your fingers and hand-to-hand, you would measure a very high ohm resistance, usually in the kilo ohm or mega ohm scale, which means that your body is generally going to under under normal voltage conditions.

It's gon na. You know conduct in these sort of million ranges and even at very low milliamps you can, you know, have enough of an electrical shock that it can electrocute you again depending on the the path that it takes. So there's a couple different factors to consider the one of them is the path, but just remember that the amperage that's gon na be drawn through your body is really a function of the power supply and whether or not it's limited or unlimited and the voltage, and So, at all of these amperage conditions, in most cases, the power supply and the building is gon na, be enough to supply that much amperage. The question just is, is how high is the voltage? This is, you know basic Ohm's law stuff the equals I times R.
So amperage is a function of the resistance more than anything else, so the voltage in the resistance and your resistance is gon na be fairly fixed. Some people are gon na have varying levels of resistance, obviously, for standing in a pool of water. It's gon na reduce your resistance from there. It's really a matter of the voltage, which is why it's far more dangerous to work with you know 480 volts than it is 120 alright, so and on any of electrocution has to do with the voltage.

So how high is the voltage power source? Is it current limited or is it essentially unlimited and when we work in a you know, building where you are connected to the utility you have essentially unlimited current available to body is not going to draw enough current to trip a breaker. So it's just gon na keep sitting there shocking you until one of you give up, then it's the resistance matters. So are you standing in a pool of water or your hands? Moist? Are you wearing proper gloves detection? That's gon na help increase that resistance. To a point that you're not going to have a current flow on, what direction does the path take through your body? Does it go through central nervous system? Obviously, if you have a short, you know from one finger to another.

On the same hand, it's not gon na be nearly as dangerous as if it goes through your body, which is why experienced technicians when they approach a panel. They usually approach it with the back of the hand, and so that way, if that, if it is grounded in some way, it's gon na cause the hand to grip away from the panel versus towards the panel. The safest place to get hit with the current is in the back of the hand and then duration, obviously the longer that you're being shot the more likely you're going to be electrocuted so to prevent electrocution. You know work only unsafe, voltages, 24 volts.

It's generally considered to be safe, if you're, not without any significant PPE. When you get in higher voltages, though, you have to really think about increasing your resistance by making sure to wear proper gloves in a rubber and leather gloves, make sure you're wearing proper work. Shoes make sure that you have face shields, all that sort of stuff we're going to talk about that later and then about the power source current. If you're connected to the utility like we normally are on the stuff.

We work on an HVAC that current is going to essentially be enough to fry you, it's it's going to just keep going until you're, fried the only exceptions to that would be things like. I said like a Taser, a very high voltage and little pulses, maybe electronic ear cleaner. But it's not enough to severely injure you at least not normally, because the current is limited because it's powered by a battery. So the amount of current is limited, whereas, when you're connected to a utility, it's just gon na keep going now be very careful about the path that it can take.
So make sure that your body is ungrounded and obviously duration. You don't want to be alone where you could potentially be shocked for a long time. This is a handout from the american electricians handbook from the 1920s. This is a real picture from the book that I actually own.

I mean this just shows you. How much has changed these guys were brilliant when it came to the engineering of electrical, but this shows the type of bravado that gets people killed. It says electricians often test circuits for the presence of voltage by touching the conductors with the fingers. This method is safe, for the voltage does not exceed 250 we're talking 250 volts.

They were testing with their fingers back in the 20s and is often very convenient for locating a blown out fuse or for ascertaining whether or not a circuit is alive. Some men can endure the electric shock that results without discomfort where, whereas others cannot, the next page goes on to talk about testing low voltages on your tongue, standing in water. I mean it's crazy. This is before meters or common, but it just shows you how much has changed and how much more safe we've gotten and our mindset about working with electrical, because this is nuts, don't do this.

The next thing is, we think, about getting shocked or electrocuted as being the most dangerous thing, but arc-flash is extremely dangerous. Anytime, you get into larger commercial and industrial applications. It becomes very important that you are aware of the voltages that you're around that you are aware of the devices any open switch gear because, again, while the goal is to always only work on on energized equipment, when you deal with large panels like this, you may Be working on an energized circuit, but you may have an energized circuit very near our flashes occur whenever there's a bridge, some sort of electrical bridge where an arc can flash across and the higher the voltage is the higher the risk is of arc flash. It's something you definitely need to be aware of.

When you think about arc flash boundary, you want to be really careful about getting no closer to the equipment. Then you need to unless you're wearing your full appropriate PPE and I'm not going to go fully into what sort of PPE you need to wear. But just be aware that when you working in industrial and commercial environments, including air conditioning systems, pulling panels off of higher voltage air conditioning systems, you need to make sure that, as you approach, you are properly covered with your personal protective equipment, which is what PPE stands For there's all sorts of different categories of PPE all the way from the very basics, no matter what you're working on you should be wearing safety, glasses and gloves. You know protective clothing, long, pants, proper work boots that are well insulated.
Leather type work boots all the way up to category 4, where you're wearing the balaclava and the face shield and the high-calorie absorption. You know arc rating of clothing. This would be the most extreme highest voltage applications, but in a lot of cases working on you know high voltage, switchgear and a commercial and industrial environment. You need to be in this category too, or category 3 range.

Again, I'm not going to cover all the specifics, but it's good for you to be aware that this exists. I'm one of the most important things to have on your truck if you're doing electrical work is a lockout tagout kit. This is true of almost every segment of the industry. I don't care if you're residential, commercial kiss, for example, even in residential, you may do multifamily where you have to go between floors and you have to work on equipment that you're shutting off where you're not line of sight to the disconnect and what a lockout tagout Setup does is it allows you to independently lock piece of equipment off at the disconnect, so that you're, the only one with the key who can unlock it to turn it on, and you can potentially put multiple locks in the lockout tagout lock, i'm so that way.

If more than one person is potentially working on the equipment, you're all going to be protected, everybody has to unlock it before the equipment can be turned on. It's very very important, very practical, certainly not, as some people think it's overkill, but it is definitely not in a lot of cases, you're shutting off units, a disconnects that are well away from where you're working, especially if you're working past the disconnect sides, they say you're, Removing a rooftop unit or doing significant work, maybe to a disconnect on the rooftop unit. You have to definitely make sure that it's locked out and tagged out so that you're not gon na somebody's not going to accidentally come along and turn it on. Another thing to consider with electrical a lot of the deaths associated with electrical are simple shocks and then result in falling, and so you always need to be.

You know properly tied off whenever you're working about 6 feet according to OSHA. Again, I'm not going to get into all the specifics, but this is especially true when you're working on electrical, because the odds that you're going to fall or increase when you're working with electrical circuits when you could potentially be shocked and fall backwards again, our goal is Never to work on live crickets, but in many cases we maybe some of those things may be out of our control. You may have some other live circuits that are adjacent to where you're working and your shock risk increases. So when your shock risk increases, if you're working off of a ladder on a roof, then your fall risk also increases.
You need to be aware of that. It's very important, whenever you're wearing up anything to make sure that it's properly grounded properly bonded throughout the structure, but also keep in mind that in some cases, when you're dealing, especially with convenience outlets, anything where there's potential moisture involved around fault circuit, interrupter GFCI is important Because, like we mentioned, you could potentially be a ground path and not draw enough amperage to trip a breaker, and so a GFCI basically looks for imbalance between neutral and the hot again. This is for 120 volt circuits. Primarily, convenience outlets is where you're gon na see this more than anything else, but it's important to understand what they do and why they matter - and this is important when you're working with you know, extension cords and that sort of thing which comes up a lot in The trade GFCIs really will help protect you because, again, like I said you can create a path to ground where it's enough to electrocute you.

But it's not enough to trip a breaker GFCI by monitoring the difference between what's going in and going out, and if it sees an imbalance, then it knows that there's some leakage to ground and it can trip arc faults. A newer thing. I just don't want you to confuse it with GFCI arc fault is actually uses a circuit board inside the breaker that looks at the potential or the possibility of arcs, and so if it sees a signal or a signature that looks like that. There's an arc in the circuit, then that will trip the breaker.

That's more for bedrooms, that sort of thing to help prevent fires. So you know GFCI is there to help protect you from being shocked or electrocuted AFCI? Is there to help prevent things from burning down? So sort of different functions and then, finally, all electrical installations should be made according to the NEC National Electrical Code, which is also known as NFPA 70. That's the National Fire Protection Association standard 70. That's the Bible for proper electrical installations, and their goal, of course, is to prevent people from getting electrocuted, prevent fires and then also prevent arc flash, but arc flash is more so covered by OSHA.

So, finally, let's just kind of sum it up. You got to be really careful about not working on energized circuits. You want to make sure to wear proper PPE. That's things like gloves, face shields, proper leather shoes.

Things like that to prevent you from getting shot. Make sure that you understand that you could have a shock that would be well enough to kill you. That's not necessarily gon na trip a breaker and use all of all the best practices to prevent yourself from being injured. So that's the basics here today, like I said, I'm gon na, do some more hands-on demonstrations to show you how to use electrical meters to help keep you safe.
Hopefully you found that helpful thanks for watching.

13 thoughts on “Electrical safety basics”
  1. Avataaar/Circle Created with python_avatars Riyad Torre says:

    Hey,
    I like your lesson. Service area Nepean??

  2. Avataaar/Circle Created with python_avatars Carlos Santibanez says:

    This video was helpful

  3. Avataaar/Circle Created with python_avatars Jackson Hill says:

    nice

  4. Avataaar/Circle Created with python_avatars freeloader says:

    excellent channel!

  5. Avataaar/Circle Created with python_avatars Phillip Tan says:

    Great short info. Very helpful!

  6. Avataaar/Circle Created with python_avatars R. Anbalagan V.Ramasamy says:

    Thank you. Some great tips.

  7. Avataaar/Circle Created with python_avatars ITILII says:

    Just don't buy junk from China, nothing but problems…as we all can see these days.

  8. Avataaar/Circle Created with python_avatars Donnie Robertson says:

    Great job again like always

  9. Avataaar/Circle Created with python_avatars Thomas Daniel Tucker says:

    Thank you for doing Safety videos. The Techs I work with here in TN. don't take safety seriously. They try to be macho, but I think it's because they dont know any better.

  10. Avataaar/Circle Created with python_avatars O. V. says:

    Also do not rely on the disconnect…look inside and verify that that line side hasn't been jumped over to the load side essential making the disconnect irrelevant…i know its dumd AF but I've seen this multiple times. Make it a habit to open that disconnect door when you use a disconnect to isolate equipment..

  11. Avataaar/Circle Created with python_avatars Schoeps MS says:

    My dad is a retired union electrician and he told me stories about the old timers testing circuits by touching conductors with fingers. Thankfully he never did that. A better rule of thumb if you will, is to always have tremendous respect for electricity. Are you in Ottawa ?

  12. Avataaar/Circle Created with python_avatars Rossy954 says:

    Proper way to check for voltage is to put a light bulb in your mouth grab the neutral side and then the line side if the bulb lights up then there is power present….lol no don't do that…

  13. Avataaar/Circle Created with python_avatars David HvacPro89 says:

    I would love to have the American Electricians Guide

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.