Electrical Safety for Everyone

Kevin Booker, Executive Director, Nebraska State Electrical Division Author

03/31/2016 Added

739 Plays

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Daily hazards of electricity and mitigation strategies.

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[00:00:05.485]Welcome to the safety colloquium
[00:00:09.050]for the spring.
[00:00:10.396]Environmental Health and Safety and the Office of Research
[00:00:13.090]would like to welcome you all here.
[00:00:15.563]This series of colloquia is offered
[00:00:18.475]in recognition of the commitment of faculty and staff
[00:00:21.711]of the University of Nebraska Lincoln
[00:00:23.527]to ensure a safe environment.
[00:00:25.732]So before we begin, a couple housekeeping items.
[00:00:28.832]There is a sign in sheet passing around
[00:00:33.000]and if the front side
[00:00:35.133]both of the sheets or three sheets get filled
[00:00:37.095]just write on the back.
[00:00:38.686]And there is a survey that I hope you all picked up.
[00:00:43.606]We would appreciate afterward if you complete the survey.
[00:00:47.518]You need not include your name
[00:00:50.199]unless you would like to be contacted.
[00:00:52.812]So today's topic is Electrical Safety for Everyone.
[00:00:57.746]Our presenter, Kevin Booker, has been
[00:00:59.708]with the Nebraska State Electrical Division
[00:01:02.692]since July 2012.
[00:01:05.047]He started as a chief electrical inspector
[00:01:07.289]and was promoted to executive director in 2016.
[00:01:12.846]Prior to that time, Kevin was the chief
[00:01:16.597]electrical inspector for the state of Wyoming
[00:01:19.488]for over five years and he holds a master
[00:01:22.228]electrician license in multiple states
[00:01:24.875]as well as being a certified electrical inspector
[00:01:27.940]and plans examiner.
[00:01:29.124]So Kevin, welcome to UNL.
[00:01:31.826]Thank you.
[00:01:32.566](applause)
[00:01:36.815]I do apologize.
[00:01:37.756]I've been fightin' a little cough so...
[00:01:41.665]"In the United States, electrical hazards are ranked
[00:01:44.696]"number six among the causes of work-related deaths."
[00:01:51.589]We're gonna kind of cover a little bit.
[00:01:53.086]I'm gonna jump over it pretty quick.
[00:01:54.967]Basically a single phase electrical panel,
[00:01:58.764]just explaining to you the difference
[00:02:00.099]between single phase, three phase
[00:02:02.432]and over current devices.
[00:02:04.882]Your just your standard breaker.
[00:02:06.601]We started out at your main breaker.
[00:02:08.481]To give you a little bit of over current protection
[00:02:12.962]that will shut down everything
[00:02:15.528]in the entire area pulling that main breaker.
[00:02:21.722]This is your standard single phase configuration.
[00:02:24.868]If this were a three phase circuit
[00:02:26.784]you'd see one extra wire there.
[00:02:28.653]So three phase is nothing really fancy.
[00:02:32.008]It's just basically you got one more 120 volt line
[00:02:35.398]coming into your building.
[00:02:42.176]So your breakers,
[00:02:45.160]your typical breakers in your house,
[00:02:46.948]your 15 and 20 amp breakers,
[00:02:49.200]typically for most of your outlets.
[00:02:53.934]Basically, what they're looking for
[00:02:55.733]is if it hits that maximum of the 15 amp
[00:02:59.936]or the 20 amp loaded
[00:03:01.457]it's gonna trip the over current device.
[00:03:07.387]That's your first form of protection.
[00:03:09.883]Some of the newer houses,
[00:03:11.311]those of you that have a house
[00:03:14.051]that was built within the last 10 years,
[00:03:16.988]you're also gonna see in your panels
[00:03:19.065]where you might have arc fault circuit interrupter.
[00:03:22.420]We all know what ground fault does.
[00:03:24.999]But arc fault, what it does it will detect
[00:03:28.308]zip cord failures.
[00:03:30.224]So where people have the Christmas tree cords,
[00:03:32.801]the little brown zip cords,
[00:03:34.345]anything like that, it will detect
[00:03:37.619]that arc to prevent a fire.
[00:03:39.825]So that's expanding every code cycle.
[00:03:43.529]We started out with just bedrooms,
[00:03:45.770]then we go to living rooms,
[00:03:48.184]kitchen, dining rooms, you know.
[00:03:51.264]And now in the next code session
[00:03:53.571]we're gonna look at that being expanded on.
[00:03:56.572]So you know, typically we see
[00:03:59.384]a lot of fires caused basically by zip cords.
[00:04:04.002]You know, people not realizing
[00:04:06.544]how much you can actually load one of these to.
[00:04:09.362]So what I did, I kind of highlighted.
[00:04:12.787]You know, a lot of these we see in dormitories.
[00:04:17.315]Two years ago in the code they actually put in
[00:04:20.334]dormitories requiring arc fault protection
[00:04:23.724]and the reason they did that because it's so easy
[00:04:26.370]to overload that one single circuit.
[00:04:29.192]So a typical, you know, office setting,
[00:04:33.894]you know, you might have a microwave oven
[00:04:36.065]plugged into one of these.
[00:04:37.238]A microwave oven averages 750
[00:04:40.578]to 1,100 watts of power.
[00:04:43.457]Then you have your computer,
[00:04:47.091]CPU, monitor, printer.
[00:04:49.539]That can be anywhere from 12 to 1,800 watts
[00:04:54.127]and I'm gonna show you in a little bit
[00:04:55.892]how to calculate the difference between watts to amps.
[00:04:59.897]So your typical UPS
[00:05:02.624]battery back up system you have
[00:05:05.654]is averages right around 2,000 watts.
[00:05:10.310]2,000 watts when we get to the calculation
[00:05:13.747]is gonna be equal to 16.6 amps.
[00:05:18.147]So you're plugged into a 60 amp circuit
[00:05:21.165]that we should never load more than 80%.
[00:05:24.637]So 80% of a 20 amp circuit is 16 amps.
[00:05:28.767]So now I got one of these here plugged in
[00:05:32.737]and each one of these is rated.
[00:05:36.705]Your typical one that you're gonna see
[00:05:39.364]in your home, in your office
[00:05:41.245]is only rated at 15 amps.
[00:05:44.147]So you take 80% of that, we're at 12 amps.
[00:05:48.478]The ones that we typically rarely see
[00:05:51.543]and the basic reason for it is
[00:05:54.399]is this outlet strip here,
[00:05:57.870]which actually has a different outlet configuration to it,
[00:06:01.911]is actually rated at 20 amps.
[00:06:05.022]So it's a heavy duty one.
[00:06:07.588]This is typically the ones that we're gonna see
[00:06:10.247]in server rooms
[00:06:12.477]or where CPU back ups are.
[00:06:16.031]You know, they're actually rated at it.
[00:06:19.305]You know the other thing that you always want to check,
[00:06:21.546]this one here actually holds ETL
[00:06:25.957]inspection on it.
[00:06:28.012]Typically the symbol that you're gonna see
[00:06:29.800]on a lot of stuff is gonna be your UL label on it.
[00:06:34.935]You know, so that's the one thing
[00:06:36.424]that you always wanna check.
[00:06:38.322]You're gonna see a lot of them that have no label on.
[00:06:41.550]That means they've never been tested.
[00:06:43.988]You gotta remember that when something is tested
[00:06:46.566]by a testing laboratory they're only tested
[00:06:49.991]to what the testing company is asking them to test to.
[00:06:54.587]So when these here are tested
[00:06:56.782]they're tested for 15 amps overall.
[00:07:00.172]So typically each one of these
[00:07:02.088]has only been tested for about seven amps.
[00:07:05.432]So they're never tested for full load.
[00:07:08.530]Even these here, when they're tested,
[00:07:10.413]they're rated at 20.
[00:07:12.326]They're actually only capable of carrying
[00:07:15.526]15 amps maximum.
[00:07:17.732]This one, as you can tell, has a 20 amp cord,
[00:07:21.157]heavy duty.
[00:07:22.628]Any time you can avoid an extension cord
[00:07:26.329]to where you have a connection.
[00:07:28.663]So I plug one thing into another into another,
[00:07:31.263]everytime you got that connection problem
[00:07:34.281]what do you get?
[00:07:35.547]You get a spark, you get a weaker
[00:07:38.566]moment, you know.
[00:07:40.725]So I'm gonna take this here,
[00:07:42.978]I plug two of these together.
[00:07:45.834]So now I've got something that's only been tested
[00:07:48.284]to about seven amps and I'm gonna plug
[00:07:50.687]another one into that.
[00:07:52.521]So you know, electric space heater.
[00:07:57.012]I got them on there somewhere.
[00:07:59.066]Yeah, 1,500 watts.
[00:08:02.491]If you look at a lot of the old (mumbling)
[00:08:05.579]type heaters they had a 1,200
[00:08:09.038]1,500 switch on for those of you
[00:08:11.372]that remember seeing the older heaters.
[00:08:13.877]You could switch the little switch from high to low.
[00:08:19.630]So basically here's that formula
[00:08:21.476]I was talkin' about earlier.
[00:08:23.473]So basically a standard 20 amp outlet's
[00:08:26.279]designed at 20 amps, so that would be 16 amps
[00:08:30.482]is what you should load it to.
[00:08:32.502]Here's the calculation of how we come up with that.
[00:08:36.379]So I'm going to have my
[00:08:39.300]2,000 watts divided by 120 volts.
[00:08:44.719]So basically how much more can I plug
[00:08:46.797]into an outlet strip that I'm already loaded to this in?
[00:08:51.415]Nothing, so the one thing
[00:08:54.271]that we see a lot of
[00:08:57.580]is these type of devices
[00:08:59.516]where you're not relying on
[00:09:03.150]where they can plug one into another.
[00:09:04.996]These here are capable of holding
[00:09:06.458]up to 60 vices and we have
[00:09:09.645]a solid connection through all of these outlets.
[00:09:14.289]So you know, little bit better
[00:09:16.424]type of configuration.
[00:09:17.807]This one here actually you can put a screw through
[00:09:20.819]so it can't accidentally be pulled out of the wall
[00:09:23.640]or unplugged.
[00:09:27.561]Here's your standard receptacle.
[00:09:31.090]It's just reverse of what your hot water sink is at home.
[00:09:34.713]You know, instead of your hot being on the left
[00:09:36.840]and your cold being on the right,
[00:09:38.918]we're just reversed here, you know.
[00:09:41.855]Here we have our neutral which is our grounding connector.
[00:09:45.698]Then we have our hot and our ground.
[00:09:48.798]You know, used to see for years
[00:09:52.060]when we had the old non-grounded plugs
[00:09:54.673]the first thing people liked to do
[00:09:55.974]was break their ground off.
[00:09:58.388]So as I'm sure everybody here already knows
[00:10:01.615]if this is missing, we don't wanna use it, right?
[00:10:06.814]So...
[00:10:11.118]And how many of you think that would be a good idea?
[00:10:15.426]There's a couple issues here, you know.
[00:10:22.299]Who do we know who put it on?
[00:10:24.145]Did a qualified person put this on?
[00:10:26.885]Or did somebody that just says,
[00:10:30.101]"Oh I put the ground wire to the green screw
[00:10:33.979]"and I just decide to hook the other two
[00:10:35.732]"to whichever side" and they don't care
[00:10:38.495]which went where.
[00:10:40.004]As you seen from the previous slide,
[00:10:41.931]it does matter.
[00:10:43.475]So you know, replacement.
[00:10:47.791]This probably isn't a real good replacement job.
[00:10:51.457]As you could also see it was probably time
[00:10:53.777]to replace that piece of equipment
[00:10:56.878]'cause you can see in here where
[00:10:59.804]that cord's showing some age
[00:11:01.846]and some wear to it.
[00:11:04.703]Here's another thing and it's a common installation
[00:11:07.315]is you know, you got your computer equipment,
[00:11:09.928]your venting.
[00:11:11.483]You need to have at least six to 12 inches
[00:11:14.990]of ventilation depending on the manufacturer.
[00:11:18.867]You know the cord that's plugged to that
[00:11:22.304](coughing) typically these white cords like that
[00:11:26.576]are only rated for about seven
[00:11:29.040]to nine amps, typically.
[00:11:32.870]So you know, how much of a load is that carrying?
[00:11:36.633]Then they also have their battery back up
[00:11:39.129]and everything all plugged into this on top of it so,
[00:11:42.670]like I showed you earlier, what is our total load.
[00:11:45.932]So you basically have to add everything up
[00:11:48.045]and say am I overloading this outlet strip
[00:11:52.096]or am I overloading this cord?
[00:11:55.766]And we all know that cords can't be used
[00:11:59.411]as permanent wiring, right?
[00:12:02.024]As far as we're concerned,
[00:12:05.692]permanent wiring is anything that's in use
[00:12:07.933]for more than 90 days.
[00:12:09.756]That's actually defined by law what it is.
[00:12:12.786]So holiday lighting, typically under 90 days.
[00:12:15.689]You've got your holiday lighting up.
[00:12:18.022]Anything more than 90 days
[00:12:20.391]is gonna be considered permanent wiring,
[00:12:23.328]which cords can't be used for permanent wiring.
[00:12:32.531]Basically that what I just talked a little bit about.
[00:12:34.807]You know, you need to figure out
[00:12:36.978]what you need for
[00:12:39.996]ventilation on that, you know.
[00:12:42.690]Not what it's gonna cost us per square foot
[00:12:45.767]for equipment space to put the equipment.
[00:12:52.152]GFI testing.
[00:12:54.120]How often do we test them?
[00:12:57.782]And do you record them
[00:12:59.419]where you're at,
[00:13:00.719]what the testing is?
[00:13:03.215]They got two different types
[00:13:04.226]of ground fault protection.
[00:13:06.222]We have one that you can mount
[00:13:07.534]in your electrical panel
[00:13:08.916]and it's got a test deal on it
[00:13:11.203]and with that comes a little sticker
[00:13:13.490]that you can put right on the inside
[00:13:15.243]of your panel cover to show that you tested
[00:13:17.322]it every month.
[00:13:19.237]This one here, basically,
[00:13:21.768]you just hit the red test button
[00:13:24.206]and you test it once a month.
[00:13:26.447]I'll be the first one to say
[00:13:28.036]that I might test the one at my own house
[00:13:30.336]every six months so I'm as guilty
[00:13:32.240]as everybody else when it comes to
[00:13:35.177]you know, doing what I should be doing also.
[00:13:41.166]And basically you press the test button.
[00:13:44.544]It also applies to the new AFCIs.
[00:13:48.213]The new AFCIs we have can be either
[00:13:50.465]a receptacle or it can be a breaker.
[00:13:54.715]Most of the time on AFCI,
[00:13:57.199]which is your arc fault circuit interrupters,
[00:14:01.718]are typically in a breaker form.
[00:14:04.516]But they do make a receptacle form.
[00:14:10.974]110.3 of the National Electrical Code
[00:14:13.796]talks about listing and labeling.
[00:14:15.757]Like I said earlier on these, you know,
[00:14:18.278]who tested it?
[00:14:19.914]You know, I could tell you on the UL ones
[00:14:23.385]what their requirements are.
[00:14:24.941]The ETL, we actually have a ETL inspector
[00:14:28.958]that comes to Lincoln once every month.
[00:14:32.023]And all the places in Lincoln that manufacture
[00:14:35.738]electrical equipment are inspected
[00:14:39.094]by the ETL inspector.
[00:14:41.567]If they have a failure at that testing laboratory,
[00:14:45.990]I know about it that same afternoon.
[00:14:48.637]So anything with an ETL
[00:14:51.650]or UL logo on
[00:14:54.216]gets pretty vigorous testing.
[00:14:56.700]What about if I bought a piece of equipment,
[00:15:00.996]it might be a specialized piece of equipment.
[00:15:04.142]We see a lot of this come in from overseas.
[00:15:07.497]Some of the welders that we see
[00:15:09.216]come to some of our welding shops.
[00:15:12.884]Some of our medical equipment comin' in
[00:15:15.971]we're seein' comin' in from Europe.
[00:15:18.388]We're seeing a lot of
[00:15:22.235]evaporation equipment.
[00:15:24.151]Testing stuff for laboratories
[00:15:25.951]coming in from other countries.
[00:15:28.308]If it doesn't have
[00:15:31.119]a testing laboratory listed on it,
[00:15:35.621]I would be very wary of using it.
[00:15:39.370]Couple things happen.
[00:15:41.006]Number one is, when it comes time
[00:15:44.143]to do an investigation if somebody does get hurt
[00:15:48.067]or that piece of equipment causes a fire
[00:15:51.364]and it hasn't been tested by a testing laboratory
[00:15:55.322]especially if it's in your home,
[00:15:57.784]your insurance company can deny your claim
[00:16:02.356]because it wasn't a listed
[00:16:05.160]and tested piece of equipment.
[00:16:07.609]So they're saying you didn't do your due diligence.
[00:16:10.790]So make sure if you're gonna buy a piece of used equipment.
[00:16:14.958]I go online maybe once a month
[00:16:17.379]to public surplus,
[00:16:19.909]which is a national surplus auction site,
[00:16:24.719]I see all kinds of odd listed equipment
[00:16:27.041]from other universities,
[00:16:29.429]schools, state agencies
[00:16:31.879]where they're trying to get rid of this stuff
[00:16:34.315]you know, because they got caught
[00:16:37.056]with it in there so, you know, in other words
[00:16:39.843]the product, you use it the way it's intended.
[00:16:43.141]Don't modify it.
[00:16:45.010]If anything is modified,
[00:16:48.306]we have field evaluators that will come out.
[00:16:51.418]They'll do an inspeciton
[00:16:52.847]on whatever the modification was
[00:16:55.668]and then they can give us a complete report
[00:16:58.965]letting us know that, hey, yes we've evaluated it.
[00:17:03.664]We've tested it per this standard
[00:17:06.587]and we've determined that yes, this piece of equipment
[00:17:10.024]is safe to be used in this setting.
[00:17:15.048]"Back in 2005, the Consumer Product
[00:17:18.585]"Safety Commission went to the electrical manufacturers
[00:17:22.398]"of GFCIs and asked them to develop self testing devices."
[00:17:26.160]Since then they have done that.
[00:17:28.377]Some of the new GFCIs that we come out with now
[00:17:32.208]typically
[00:17:35.445]your five, 10, 12 dollar ones
[00:17:38.800]aren't self testing.
[00:17:41.366]Your more expensive ones are.
[00:17:44.024]They're moving to make sure
[00:17:45.359]that anything manufactured now
[00:17:47.647]will be self testing.
[00:17:50.096]So if it fails its own self test,
[00:17:54.102]what do you think it does?
[00:17:56.017]It basically shuts itself down.
[00:17:58.630]So if you go to plug into a GFCI that's self testing.
[00:18:02.912]So does anybody know what basically the,
[00:18:08.081]what are we looking for milliamp protection
[00:18:10.450]on a ground fault protection?
[00:18:12.587]We're looking between three and a half
[00:18:14.665]to five milliamp is what most of
[00:18:18.772]our residential and light commercial ones are.
[00:18:22.603]We can go all the way up to 30 and 50
[00:18:25.471]milliamp protection to protect industrial machinery,
[00:18:30.474]special pieces of equipment,
[00:18:33.238]especially that it might also be incorporating
[00:18:36.094]some type of use for a water spray
[00:18:39.519]wash type piece of machinery.
[00:18:41.934]So then we'll see a little higher one
[00:18:44.546]'cause they're designed to protect the machinery.
[00:18:49.318]Here's an example, the use of the
[00:18:54.109]outlet strips and how they got one plugged into the other.
[00:18:58.265]You know, you take a look at their computer.
[00:19:00.843]What else do they have plugged into that?
[00:19:04.024]You know, what's the total load?
[00:19:06.439]Most equipment you can look
[00:19:08.807]at that specific piece of equipment
[00:19:11.013]and it will tell you either in amps or watts
[00:19:15.263]what something is going to draw.
[00:19:18.931]So it might be a fan, cooling fan
[00:19:22.356]pointed at the back of this.
[00:19:23.587]It might only be 150 watts.
[00:19:26.327]You know, this might be 600 to 700 watts
[00:19:29.299]for this computer, so (coughing).
[00:19:33.101]Like I say, when you're using outlet strips
[00:19:35.883]it's so easy to overload these,
[00:19:38.441]which could result in a fire.
[00:19:42.422]As she said earlier, I came from Wyoming.
[00:19:45.069]In Wyoming I was a certified origin and cause investigator.
[00:19:48.750]I've investigated a number of these fires.
[00:19:51.977]You know, it doesn't take much
[00:19:55.077]to start a fire, you know.
[00:19:59.416]That's why back, like I say, two years ago
[00:20:01.587]they even expanded the requirement
[00:20:04.107]out the covered dormitories.
[00:20:06.069]So if you're gonna build a brand new dormitory today,
[00:20:09.087]them outlets in that dormitory
[00:20:10.887]are also gonna be arc fault protected.
[00:20:13.627]Because most of us remember
[00:20:16.076]back in our college days
[00:20:18.398]how much stuff did we have plugged in
[00:20:20.685]to that one outlet strip?
[00:20:23.007]I know me, I had a whole lot of stuff
[00:20:24.714]plugged into mine.
[00:20:26.467]So you know, what is the rating of it?
[00:20:32.931]You know, couple other devices
[00:20:34.555]just kinda giving the idea on
[00:20:37.308]you know, the one up at the top left
[00:20:39.676]where they just kept adding the plug on outlets.
[00:20:42.939]You know, what's the rating of that?
[00:20:45.760]We know what the combined rating is,
[00:20:48.359]but what is the individual rating
[00:20:50.613]of each thing plugged in?
[00:20:52.540]It starts to overheat.
[00:20:54.281]As it overheats, what happens to the metal
[00:20:57.103]that that's plugged into?
[00:20:59.030]It weakens.
[00:21:00.540]It crystalizes, breaks, causes fire.
[00:21:07.525]Talked earlier about cords not being used
[00:21:09.325]for permanent wiring.
[00:21:11.031]Here's one going through a suspended ceiling.
[00:21:14.050]One (coughing) couple where they went through the wall.
[00:21:18.253]One they did a really nice job
[00:21:19.681]patching that one up, you know.
[00:21:22.491]Cords not to be used as permanent wiring.
[00:21:25.683]The one way over on the right.
[00:21:29.697]See that all the time.
[00:21:30.672]As I travel through the state,
[00:21:33.087]I go to a lot of public schools,
[00:21:36.187]motels, hotels, where they got meeting room.
[00:21:40.355]What's the easiest way for me to get power
[00:21:44.244]to that Powerpoint projector
[00:21:46.241]if I don't have an outlet up there?
[00:21:49.144]Lift up simple ceiling tile,
[00:21:50.618]throw that extension cord around
[00:21:52.696]and plug it in.
[00:21:54.124]Next time you have a meeting in a motel,
[00:21:58.118]take a look and see
[00:22:01.238]how that thing's wired.
[00:22:03.026]You know, originally a lot these older motels,
[00:22:06.904]they never had Powerpoint projectors back then,
[00:22:09.923]so they called their local maintenance guy
[00:22:11.838]and he says, "Oh yeah, no problem"
[00:22:14.334]and he throws the cord up and over
[00:22:16.053]like we see in the illustration there.
[00:22:22.516]Couple more examples of the outlet strips.
[00:22:29.016]Here somebody made their own, you know.
[00:22:31.963]When it's homemade like that, do we know,
[00:22:35.470]number one, who made it?
[00:22:37.594]Has it ever been tested?
[00:22:39.475]And did they test it?
[00:22:40.938]Is it wired correctly?
[00:22:43.306]And is this here the approved fitting
[00:22:49.770]to be going into the box with, you know?
[00:22:53.160]That should be a cord grip connection,
[00:22:55.401]which would hold that cord without compressing
[00:22:58.663]the conductors.
[00:23:00.044]You get compression on there you cause heat.
[00:23:03.401]So something like that, you know,
[00:23:06.999]who put it together?
[00:23:09.251]Did they know what they were doing?
[00:23:11.086]You know...
[00:23:13.907]Here's another one we seen on the earlier picture
[00:23:16.844]where we had a frayed cord.
[00:23:19.178]We see this a lot.
[00:23:21.082]We see a frayed cord like that
[00:23:22.475]the first thing we should do is stop using it.
[00:23:33.211]And here basically talks about, you know,
[00:23:35.011]the penetrate, the outer jacket, you know.
[00:23:41.322]So basically keep that.
[00:23:42.541]There's the OSHA standard.
[00:23:44.422]1926.416 E one
[00:23:48.578]is the OSHA standard.
[00:23:50.980]So if somebody got injured
[00:23:53.059]as a result of that frayed cord,
[00:23:56.726]you know, OSHA's gonna wanna know
[00:23:59.178]how come that happened, you know.
[00:24:01.790]Here if we have a OSHA related
[00:24:05.278]accident chances are we're probably
[00:24:09.275]gonna also get a call.
[00:24:11.385]I had a call three months ago.
[00:24:13.963]We had a large manufacturing facility
[00:24:16.772]had a piece of equipment
[00:24:18.084]very similar to that.
[00:24:19.872]The outer jacket of the cable
[00:24:22.450]was falling off.
[00:24:25.143]That's actually not what caused the guy to get hurt.
[00:24:29.555]What actually caused him was their maintenance man
[00:24:32.411]had bypassed the safety interlocks,
[00:24:34.570]which is to shut down that piece of equipment.
[00:24:37.879]So you know, but we get there.
[00:24:43.019]We wrote up everything in that facility.
[00:24:45.968]I went back two weeks later
[00:24:48.568]and you could of ate off of that floor
[00:24:50.157]when I got done 'cause that place
[00:24:52.342]was spic and span.
[00:24:53.758]So usually
[00:24:56.623]nothing happens until after the accident.
[00:24:59.932]You know, the best that you can do
[00:25:01.523]is to be proactive.
[00:25:03.577]Another example of frayed cord.
[00:25:07.223]Using cords as permanent wiring.
[00:25:13.849]You know, I'm gonna touch real briefly.
[00:25:16.299]How many of you have ever thought about
[00:25:19.236]a three way and a four way light switch?
[00:25:21.488]What actually makes these?
[00:25:22.719]Are they really that complicated?
[00:25:25.203]So I actually have a set of three ways here.
[00:25:29.081]All that three way switch is
[00:25:30.707]that's in your house
[00:25:32.715]is I have one main wire comin' in.
[00:25:37.080]These other two that are travelers,
[00:25:39.693]when I turn that switch in one direction
[00:25:42.084]or the other, the only thing it's doing
[00:25:44.464]is it is moving the connection from this wire
[00:25:48.957]to either the black or the red.
[00:25:51.372]So when you turn on the other light switch,
[00:25:53.300]what are ya doin'?
[00:25:53.950]You're makin' that connection again,
[00:25:55.575]kind of like a teeter totter.
[00:25:57.537]You know, three way switch,
[00:25:59.790]when they're both set the same,
[00:26:01.694]they're makin' a connection.
[00:26:02.762]I shut one off, it breaks that connection.
[00:26:05.002]So, basically, three way switches
[00:26:07.336]are actually fairly easy to understand.
[00:26:10.680]The same rules going to apply to a four way switch.
[00:26:15.924]Standard wiring that you're gonna see most common
[00:26:18.420]is your 14 and your 12.
[00:26:22.088]Even though a number 12 gauge wire
[00:26:25.607]could actually handle up to a 25 amp load,
[00:26:30.582]we actually protect them at 20 amps.
[00:26:34.021]So that way we would rather take the chance
[00:26:38.316]of having that breaker trip at 20 amps
[00:26:41.416]than we would the wiring in the wall overheating.
[00:26:45.247]So even though the wire will handle more of a load,
[00:26:48.150]we're protecting it with the overcurrent device
[00:26:52.678]rated less than what the wire will handle.
[00:27:01.103]Kind of gives you an idea
[00:27:02.335]on what's some of the different ampacity ranges
[00:27:04.784]that you should be loading something to.
[00:27:07.722]So a typical 15 amp configuration,
[00:27:11.112]which is your standard configuration
[00:27:14.280]that you see here, both up and down
[00:27:16.905]and (mumbling) ground
[00:27:18.739]should never be loaded more than 12 amps.
[00:27:22.904]Your other configuration is your 20 amp
[00:27:26.085]where it has your ground, one up and down
[00:27:28.500]and the other one is sideways.
[00:27:30.985]That can actually be loaded to
[00:27:33.794]13 to 16 amps.
[00:27:38.702]Then we also get to our larger conductors,
[00:27:40.943]which typically you're probably not going to be dealing
[00:27:43.242]with anything.
[00:27:44.426]The risk and hazards.
[00:27:49.938]What's the best way to prevent them?
[00:27:54.636]Avoid energized circuits is the safest way.
[00:27:57.121]So if you see a cord that is frayed,
[00:28:01.811]you know, or if somebody runs over it
[00:28:03.878]with a utility cart or you know, somehow
[00:28:06.885]it becomes damaged, you know,
[00:28:10.368]don't unplug it where it's damaged.
[00:28:11.889]Unplug it wherever the source is.
[00:28:13.757]Go ahead of the source and avoid touching it
[00:28:18.652]if it's energized.
[00:28:23.032]So stop and think before you take action.
[00:28:27.362]Think about the risks and hazards
[00:28:29.150]that could be there.
[00:28:31.006]What my options are, you know.
[00:28:33.975]I could go back and shut the breaker off
[00:28:35.938]using your standard lockout/tagout,
[00:28:39.155]which basically all it is is a little red
[00:28:41.940]piece of plastic in most cases
[00:28:44.843]that you put a padlock through
[00:28:47.130]and they put a label saying, "This circuit
[00:28:48.964]"is shut off because of this."
[00:28:51.542]That's something that typically
[00:28:53.701]is gonna be done at the breaker box.
[00:28:56.915]And the reason for that is you don't wanna
[00:28:58.519]turn it off and get all the way out to
[00:29:02.840]unplug the affected piece of equipment
[00:29:04.963]just to find out that somebody else realized
[00:29:07.134]they didn't have power and they went back
[00:29:08.643]and turned it back on while you were working on it.
[00:29:15.226]In this case, most of you aren't going to be
[00:29:17.060]equipped with PPE, you know.
[00:29:20.404]PPE is basically if you're gonna be working
[00:29:22.842]on a piece of energized equipment,
[00:29:24.769]working inside your breaker box
[00:29:26.778]or large piece of equipment, you know.
[00:29:30.122]The PPE that I carry in my truck
[00:29:33.767]is just basically a duffle bag full of equipment
[00:29:36.437]that costs $5,000.
[00:29:38.887]So it's listed, it's rated.
[00:29:42.068]I rarely wear it
[00:29:45.385]because normally we're looking at stuff
[00:29:47.022]before it gets energized.
[00:29:51.876]What are the hazards and risk?
[00:29:55.124]Number one, you could get shocked.
[00:29:57.121]The arc flash or arc blast,
[00:29:58.839]if any of you have ever seen
[00:30:01.207]an electrical blast of energy,
[00:30:04.760]it's just, you think you seen something
[00:30:07.616]the fourth of July, you oughta see
[00:30:09.392]an electrical blast of energy, you know.
[00:30:15.024]And fire ignition.
[00:30:17.310]It's the most common that we're gonna see.
[00:30:20.438]Is it's gonna overheat, it's gonna cause fire.
[00:30:26.453]What's gonna happen if you do come in contact with it?
[00:30:30.040]Number one is sometimes your muscles
[00:30:32.326]are gonna contract.
[00:30:33.407]You may not be able to let go of that circuit.
[00:30:37.842]We had that case happen last year.
[00:30:40.231]We had a farmer installing irrigation system,
[00:30:43.784]couldn't figure out why it wasn't working
[00:30:45.502]so the first thing he does is reach down
[00:30:47.626]in this wet trench and he
[00:30:51.922]pulls up the wire and he just happen to grab it
[00:30:55.359]right where it'd been shaved off.
[00:30:57.692]He couldn't let go.
[00:30:59.318]His hired men literally had to kick him off of it.
[00:31:02.383]So depending on the conditions, the humidity,
[00:31:06.493]all kinds of stuff, depending on your size,
[00:31:09.082]your weight, your build, you know,
[00:31:11.160]we can all handle different amounts
[00:31:13.845]of electrical energy.
[00:31:16.864]You know, and conditions that affected his,
[00:31:19.929]you know, the environment.
[00:31:22.572]You know, the other thing is we can have organ damage,
[00:31:25.928]tingling, pain, you know, a lot of times
[00:31:29.654]if you've ever been shocked
[00:31:33.548]by anything, you're gonna feel that pain
[00:31:37.810]probably up your arm maybe for two or three weeks,
[00:31:40.827]you know, so it's one thing that, you know.
[00:31:45.308]And like I say, plus it could affect your breathing.
[00:31:49.951]You know, you could be disoriented.
[00:31:52.679]I remember the first time
[00:31:54.353]that I accidentally when I was an apprentice
[00:31:58.844]had one of the ground conductors
[00:32:00.760]touch one of my lugs in my panel
[00:32:04.881]and once I got up off the floor
[00:32:07.808]I was disoriented for quite a while.
[00:32:10.756]So it could cause disorien-ish, dizziness,
[00:32:14.552]you know, and possibly death.
[00:32:17.037]You know, at least once a year
[00:32:18.674]we have death resulting to electrical injury.
[00:32:22.877]So we investigate at least one a year.
[00:32:28.586]The long term effects can be memory loss,
[00:32:31.488]nervous disorders, chemical imbalances,
[00:32:35.436]damage to your vital organs.
[00:32:38.002]You know, sometimes fatal.
[00:32:39.731]The one that we had two weeks ago
[00:32:41.728]with the lineman up in Pierce, Nebraska was fatal, you know.
[00:32:46.094]He came in contact with a high voltage line
[00:32:48.427]and he died from it.
[00:32:50.714]So...
[00:32:56.183]Effects of current on the body, like I said earlier,
[00:32:58.260]men, women, your size.
[00:33:00.961]Everything, you know.
[00:33:04.536]At what point can you let go of something?
[00:33:06.811]It all depends, like I said,
[00:33:07.996]what is the amount of contact you have,
[00:33:12.616]what your resistance is,
[00:33:14.044]where you're standing, you know.
[00:33:18.453]Men can actually handle a little bit more of it, you know.
[00:33:24.060]I think the other chart here is gonna basically
[00:33:25.776]compare that to what women can handle.
[00:33:29.709]So where a man can handle one milliamp,
[00:33:32.042]a woman threshold is, you know,
[00:33:34.724]seven tenths of a milliamp.
[00:33:37.580]Shock nine milliamps for men,
[00:33:40.970]you know, six for women.
[00:33:44.938]Once you start getting up in here
[00:33:48.038]through your 10, your 100, your 500,
[00:33:51.625]that's why our ground fault GFCI protection
[00:33:54.284]is set at five milliamps.
[00:33:57.289]You know, five milliamp you can still get
[00:33:59.984]a pretty good zap off of it.
[00:34:03.942]You get anything over the five milliamp
[00:34:06.730]as you can see here, you can start
[00:34:10.085]resulting some serious injury.
[00:34:13.066]Types of burns.
[00:34:16.772]Typically, if it's a high enough voltage,
[00:34:18.618]we're gonna see both the entrance and the exit.
[00:34:21.994]So you know, somebody's holding on to the rail
[00:34:25.700]of their boom truck over here which is a steel rail,
[00:34:29.253]we're up here holding onto a line.
[00:34:32.201]We're gonna have our entrance where we came in contact with.
[00:34:35.525]We're also gonna have our exit.
[00:34:37.232]A lot of times the exit's probably gonna be worse
[00:34:39.194]than where it came in at.
[00:34:45.030]It could be anywhere from a first to a third degree burn.
[00:34:48.502]So anything from a minor to a severe burn.
[00:34:58.182]A second degree burn threshold,
[00:35:01.072]just a curable threshold,
[00:35:03.406]skin temperature raised to
[00:35:06.227]175 degrees for one second.
[00:35:08.642]So it doesn't take very long
[00:35:11.208]to get a second degree burn.
[00:35:14.758]And basically a third degree is gonna be
[00:35:16.638]your 200 degree Fahrenheit.
[00:35:21.012]Eardrum damage, lung damage.
[00:35:25.830]Internal tissue burns.
[00:35:28.895]This is probably one of the worse ones there is, you know.
[00:35:34.096]I spent a lot of time years ago
[00:35:36.830]wiring communication equipment.
[00:35:39.151]So you get the radiation burns
[00:35:41.114]from a radial transmitter, something like that
[00:35:45.640]where you're gonna have a internal burn
[00:35:49.531]is also extremely painful and can last
[00:35:53.490]for years.
[00:35:58.084]And then our fourth degree would be our internal
[00:36:00.627]and organ damage and as a rule
[00:36:03.855]that is typically fatal so...
[00:36:10.867]Protection from abnormal conditions are 70E
[00:36:13.595]is the electrical safety code.
[00:36:15.848]It's actually taken out of the electrical code book
[00:36:19.400]that the electricians carry
[00:36:21.444]and it's taken that information for what your working spaces
[00:36:25.517]and clear distances are and it's putting that
[00:36:28.584]into a safety code which is the 70E.
[00:36:31.777]Then we also have our part 19 OSHA standards
[00:36:35.120]that we deal with.
[00:36:36.873]I would assume that here you probably have
[00:36:39.567]an electrical safety manual for your
[00:36:42.944]employees as far as what they can and can't do.
[00:36:48.541]And training.
[00:36:50.051]Are they trained?
[00:36:52.593]When you get to the electrical code,
[00:36:54.474]we define it as are they qualified?
[00:36:57.620]Have they had the education and training
[00:37:00.117]to do what they were doing?
[00:37:02.392]You know, do I have a brand new apprentice
[00:37:05.678]wiring an energized panel?
[00:37:08.290]Have they been trained for what they're doin'?
[00:37:11.401]Equipment labeling.
[00:37:13.038]A lot of that times it's gonna give you
[00:37:15.244]what your approach PPE is required.
[00:37:19.087]It'll tell you what category of equipment you need,
[00:37:22.640]how many volts that equipment is
[00:37:25.055]and it's gonna tell you what a safe working distance is
[00:37:28.886]from that piece of equipment.
[00:37:31.301]And most of the time, it's going to be a label
[00:37:33.588]similar to this telling you what
[00:37:37.211]type of equipment.
[00:37:38.929]Here's it's gonna tell you how many calories we have
[00:37:41.901]and what the electrical category hazard is.
[00:37:47.863]So basically, we're down to questions.
[00:37:50.533]Anybody have any questions?
[00:37:53.633]Or something I didn't explain well enough?
[00:37:57.383]Up here.
[00:38:00.828]On your six outlet box.
[00:38:02.662]Yes sir?
[00:38:03.440]Is that considered an extension cord?
[00:38:05.275]Or is it considered an outlet?
[00:38:07.237]It's actually considered and rated at being
[00:38:10.905]a piece of permanent equipment.
[00:38:13.274]So it's not listed as an extension cord.
[00:38:16.535]So it's listed--
[00:38:17.616]We can plug one extension cord into that?
[00:38:19.810]No, nope.
[00:38:21.691]This is designed, basically,
[00:38:23.816]when you get these six you're loaded.
[00:38:26.184]You can't plug,
[00:38:28.553]it's not rated for you to plug this into this
[00:38:31.745]and then continue on.
[00:38:34.636]This is rated to only have one piece of equipment
[00:38:38.119]in each slot.
[00:38:40.244]My other question is
[00:38:42.125]when you're dealing with resistive loads
[00:38:46.223]and you've got ground fault interrupts,
[00:38:50.622]Yes.
[00:38:51.863]Do you design it
[00:38:54.165]for a higher amperage?
[00:38:57.101]We don't design it for a higher amperage.
[00:38:59.390]The amperage rating of what the ground fault is tested for
[00:39:02.768]is tested by the manufacturer
[00:39:06.124]to the listing and labeling of the piece of equipment,
[00:39:09.467]but depending on what you're gonna use
[00:39:11.186]that ground fault for, is it used for personal protection
[00:39:15.342]or equipment protection?
[00:39:17.803]It's equipment protection.
[00:39:18.813]Equipment protection, it can be anywhere
[00:39:20.938]from 30 to 50 milliamp
[00:39:23.794]and that's all it's designed for
[00:39:26.128]is to protect that equipment.
[00:39:28.949]As you can see from the chart
[00:39:30.899]of where you can start to have damges at,
[00:39:34.487]you know, anything over the 10 milliamp
[00:39:36.286]can be severe.
[00:39:37.680]Yeah, but you know a resistive load
[00:39:40.489]will spike it and then it will come back down.
[00:39:43.264]Yes, so what that's designed to do,
[00:39:48.237]a lot of your larger equipment,
[00:39:50.207]not only does it have the ground fault protection,
[00:39:54.051]it also has a surge rating.
[00:39:56.732]So a lot of your larger equipment
[00:39:59.346]will also tell you what the surge rating is
[00:40:03.061]of that piece of equipment.
[00:40:04.326]But typically, when you get to that
[00:40:08.030]you are,
[00:40:10.445]where we see it most often,
[00:40:11.873]where we get concerned about it
[00:40:13.429]is X-ray equipment.
[00:40:15.843]You're in the doctor's office,
[00:40:17.434]that X-ray kicks in,
[00:40:20.046]that thing might spike
[00:40:21.323]where it normally draws 30 amps.
[00:40:23.111]It might spike to 150 amps,
[00:40:25.642]which is kind of like what you're talking about there.
[00:40:28.011]It's just that in rush or that surge.
[00:40:31.772]And a lot of times
[00:40:32.794]that'll trip your GFCI.
[00:40:34.210]It will.
[00:40:35.406]And so you gotta design it
[00:40:37.403]so that it can handle that surge.
[00:40:39.121]Yes and that's where you wanna design and test it.
[00:40:50.508]Any other questions?
[00:40:55.605]Okay well, thank you so much for attending
[00:40:58.472]and if you would please complete the survey
[00:41:02.431]and a reminder, unless you want me to contact you
[00:41:06.471]you need not put your name on the bottom of those.
[00:41:09.327]And you can just leave them somewhere
[00:41:11.777]on that back table and grab a cookie on the way out.
[00:41:15.446]Thank you for coming.

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electricity safety
electrical
Kevin Booker

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I thought the speaker did an excellent job of explaining the details about electrical safety! There are many people that don't understand or believe the danger and harm that can come from not following the guidelines that you should with electricity. Thank you for sharing this information.

Lori Wentz
04/12/16 5:03 pm

Electrical Safety for Everyone

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