hpr-knowledge-base/hpr_transcripts/hpr3213.txt

Episode: 3213
Title: HPR3213: Electrical Safety
Source: https://hub.hackerpublicradio.org/ccdn.php?filename=/eps/hpr3213/hpr3213.mp3
Transcribed: 2025-10-24 18:57:46

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This is Haka Public Radio episode 3213 for Wednesday, 25th of November 2020.
Today's show is entitled, Electrical Safety.
It is the 20th show on Port Work and is about 31 minutes long and carrying a clean flag.
The summer is, I discuss why and how I stay safe when working with electricity, when summer can be at the end.
This episode of HBR is brought to you by an honest host.com.
Get 15% discount on all shared hosting with the offer code HBR15. That's HBR15.
Better web hosting that's honest and fair at An honest host.com.
Good day, good listener of Hacker Public Radio and welcome back to the Paul Courts Show.
In this episode, I'm going to talk about electrical safety.
As a licensed electrician, this is a topic on which I know very well.
However, this podcast is not intended as advice or how to.
It's also not intended to spread fear or pressure anyone into anything.
Also, I am not certified to teach a safety course.
Most of my teaching at the local community college deals with trade specific subjects,
such as instrumentation and electronics, which do not require certification beyond my trade license
and demonstrated understanding and ability of these subjects.
Though, I am required to maintain all of my relevant safety certifications
for my continued employment either at the local college or on the job site.
This episode is going to be an honest conversation from me about electrical safety
and nothing about this podcast has been endorsed by my union nor by any of my employers.
My reasons for doing this episode are because it is likely that a listener of Hacker Public Radio
is probably smart enough to do a lot of their own electrical work.
There are not a lot of people in this community and I want each and every one of you to be safe.
And so I'm going to do my best to make this as interesting as possible
while helping you to understand the real dangers of electricity.
First of all, I want to start with why this is so important.
Quite simply put, electricity can kill you and it can burn your house down.
We live in a day and age where we take for granted that electricity is pretty safe.
We can turn lights on and off, plug in electrical equipment, and even reset a tripped breaker
all without fearing electrocution or fire.
However, it wasn't always that way.
Take the word electrocution, for example.
This was not a word used in our vocabulary until around 1897 and it literally means
execution by electricity.
This was not fear-mongering zoodle science.
Getting electricity into your home in the late 1800s was a craze,
much like getting internet in our homes was a craze in the late 1990s.
There were no regulations, so whether you would get AC or DC power
and whatever voltage you would get could vary from city to city.
To the point where an electric iron purchased in one part of the country
may not have worked at all in another part of the country.
These were early days where houses getting burned down and people getting killed by electricity
made the news.
It wasn't that people were stupid or foolish and they were no less intelligent than we are today.
They just didn't fully understand the dangers because electricity is a force.
That is not readily observable by our natural senses.
At the time, many houses were being lit by gas lighting which presented an even greater danger
of fire and death from carbon monoxide poisoning and these deaths also made the news.
Many homes and buildings were converted from gas lights to electrical lights and this is the
reason why rigid conduit used for electrical work in industry today is nearly identical
to gas pipes and fittings used in the installation of natural gas.
In some cases, an electrical installation may have been a bear wire hanging from a ceiling
to a light. In the early days, there was no such thing as overcurrent protection,
no fuses and forget about breakers, so a short circuit could really burn down someone's house.
Today, the current Canadian electrical code is the 24th edition which was last updated in the year
2018. It's a book that measures approximately 21 centimeters by 28 centimeters and contains
953 pages. In addition to this, each province can have their own amendments to this.
Section 0 of this code book entitled Object, Scope and Definitions makes it clear that the
object of this code is to quote, establish safety standards for the installation and maintenance
of electrical equipment. However, they have made it very clear that.
And I quote, this code is not intended as a design specification,
nor as an instruction manual for untrained persons. This means that in addition to this code book,
it is expected that a licensed electrician would have completed an apprenticeship which generally
lasts around five years in addition to understanding this book with regards to electrical installations.
And this really is the reason why we don't hear about death by electricity or homes being burned
down by electricity much these days anymore. There are redundancies in place as well as oversizing
of everything. For example, a standard 15 amp circuit breaker would be used on a circuit designed
to carry no more than 12 amps for current. The size of the breaker cannot be greater than the wire
it is protecting, which means we cannot use number 14 wire rated at 15 amps with a 20 amp circuit
breaker. That's not to say that you can't physically do this. In fact, a common hack decades ago
was to replace a blown fuse with a bigger fuse if that fuse kept blowing. The problem, of course,
is that when a 15 amp fuse blows, it will blow before the current gets too high for the wire,
or more specifically, the wire is insulation. When a wire is too small for the current it is
carrying, it becomes very hot like a burner on a stove. The insulation can then melt off
because the current carrying capacity of a wire is actually determined by its insulation,
not necessarily the wire itself. And so the wire will continue to conduct as much current
is available until an overcurrent protection device like a fuse or breaker does its job.
This is what will cause a house to burn down because houses are made out of wood.
And the wires in houses are run through small holes in that wood. So if a breaker keeps tripping
or a fuse keeps blowing, there is a serious underlying problem that needs to be found,
because as good as modern circuit breakers and fuses are, they are still manufacture products
designed to a price point. There are certain breakers that we come across in the trade that have
a reputation of not tripping when they're supposed to. And I'm pretty sure those companies aren't
around anymore, but their circuit breakers certainly are. Another issue with breakers is that,
unless they're switched rated, they're not supposed to be used as switches. And they can only
take so many trips before they should be replaced. The fact that today's circuit breakers are
designed so well means people will do things like use them as light switches or induce a short
circuit in order to discover which circuit breaker the circuit is on, but I'm going to ask you.
No, I'm going to beg you to please don't ever do any of these things. I mean, if you know that
a circuit breaker is switch rated or designed to tolerate constant tripping, that's one thing.
However, you can safely assume that the circuit breakers in your home were probably the least
expensive the contractor could buy at the time. Of course, you will want to turn off a circuit breaker
before working on that circuit, as non-switch rated circuit breakers obviously can take me and turn
on and off quite a few times because that's how they're designed. However, as standard trade practice,
I always stand to one side of any panel that has a breaker I'm turning on and turn my head away
while turning it on, because in rare instances certain breakers have been known to explode when they
fail. We call the explosion an arc flash and I will put some links to videos in the show notes.
Once again, I'd like to remind you that I'm not trying to scare you from resetting a breaker on
your circuit breaker panel. If a breaker trips and you know it's because you just plugged in a space
heater or a hairdryer for example, you should understand that most space heaters and hairdryers
will use up all the capacity on the circuit they're plugged into. So let's do a little bit of math.
A 1500 watt heater or hairdryer divided by 120 volts gives us 12.5 amps.
Remember earlier when I said a 15 amp breaker should not be loaded up beyond 12 amps?
That's because of the 80 percent rule. That 1500 watt heating appliance actually bends that
rule a little bit by drawing an extra half amp. It's still well within what the wire is rated at
and within the tolerance of a modern circuit breaker, but that appliance can be the only thing on that
circuit. When I want to reduce the risk of a potential circuit breaker explosion when I reset it,
I make sure to turn off and disconnect all of the electrical loads on that circuit before resetting
the breaker. This way, very little to no current will be flowing through the breaker contacts when
it's reset. Now at this point, I might have lost some of you by talking about watts and amps,
so I'm going to talk a bit about ohms law. Now when many people think of electricity,
they think of electricity as this thing that is measured by a number and the most common number
people are familiar with is the volt. We know for example that 120 volts is half of 240 volts
and that our cars run on a 12 volt electrical system. Voltage is important because electronic
devices are designed to work within a specific voltage range. Too little or too much voltage
can damage the components of an electrical device. Voltage is the electrical potential between
two points. Think of it like electric pressure or tension. A static electric shock could have a
voltage potential of over 20,000 volts while the battery in a wristwatch might only have a
potential of 1.5 volts. The other component of electricity is current, which is measured in amps.
Think of this as the flow of electricity. Together, voltage and current gives us the watt,
which is a unit of power that describes how much power we use when we multiply voltage by current.
The relationship between voltage and current are intertwined. If we increase the voltage,
we can decrease the current and maintain the same amount of power. Therefore, we know that a 60 watt
light bulb at 120 volts will use half an amp. Using this, in addition to the 80 percent rule,
we understand that we could put up to 24 of the 60 watt light bulbs on a single 50 amp circuit
to use the same 12.5 amps that a heating appliance would. This should give you some perspective on
just how much power is being drawn by a space heater or a hairdryer. Now, I think I'd like to talk
about current and its effects on the human body. You've probably heard the old phrase,
it's not the voltage that kills, but the current. Just how much current do you think it would take
to kill you? Well, the answer is less than half an amp, with the general consensus among experts
being between 0.1 and 0.2 amps. Now, I know that some might be thinking there's no way that
could be true, as even I personally have received electrical shocks that have been much greater than
this. Now, the real problem lies in which path the electricity takes through your body and how
much resistance your body provides to the flow of electricity. For example, if you were to stick
your finger in a light socket and you got a shock, there's a pretty good chance that the side of
your finger was touching the side of the light socket, so the electricity would be flowing between
your finger tip and the side of your finger that's touching the side of the socket. It would certainly
hurt, but it's not likely the electricity would have found a path through your heart. However,
if you were standing on a wet basement floor and did the same thing, there's a pretty good chance
that some of the current may find its way through your arm and body to your feet, as that may
represent the easiest path to ground for some of the current in your finger, and your heart is
definitely much closer to that path. If you've ever seen a bolt of lightning photographed,
you will see that most of the electricity will be concentrated along the easiest path to ground,
but there are still branches off the main bolt that find alternate paths to ground.
For this reason, anywhere in your home where there is water near an electrical outlet,
either inside or out, we are required to install a ground fault circuit interrupter or GFCI
receptacle. A GFCI is designed to trip at 5 milliamps, which is a lot lower than the 100 to 200
milliamps it takes to stop your heart. It works by measuring the current flow between the neutral
and the hot connections in the receptacle. Under normal use, the current that flows into the
electrical device is equal to the current that flows out of the device. When the current flow
between the hot and neutral become unbalanced, it means the electricity has found another path
to ground other than the neutral, and a 5 milliamp difference will cause the GFCI to trip.
These have a test and reset button on them, and they are designed to be tested on a regular basis.
I strongly encourage you to test your GFCI monthly, and if you cannot do that,
at least test them quarterly. You should feel a click when pressing the test button,
and there should be not be any power available at the receptacle until you press the reset button.
If you cannot reset it, this means the receptacle has failed. GFCIs don't last forever,
so if either the test or reset buttons don't work anymore, you need to stop using that receptacle
until it's replaced. You can expect them to last between 7-10 years, and I do not recommend
cheaping out on this life-saving device. If you experience nuisance tripping on a new GFCI,
there could be another electrical fault that is causing this that needs to be addressed.
Whatever you do, never replace a GFCI with a standard receptacle. Prior to their widespread use,
nearly 800 people died annually from household electrocutions.
Ever since ground fault circuit inteructors have become mandatory, that number has dropped
to less than 200. I would like to see that number drop to zero, so please share this information
with everyone you know. Now, by now you might be thinking, I must be brave to work with electricity
every day. On the contrary, I'm probably one of the biggest cowards when it comes to electricity.
In fact, it is one of my greatest fears. At this point of the show, I'm going to discuss with you how
I protect myself when working with electricity. First of all, I dress appropriately. I always wear
safety boots with the white rectangle tag that has an orange Greek omega letter. This indicates
that the sole of these boots will provide resistance to electrical shock. This way, if I were to
accidentally touch a live wire, the path through my body and through my feet into the floor
is not likely to be the easiest path to ground. Of course, I replace my work boots when the
soles are worn in order to maintain this protection. This is a secondary level of protection
in my safety plan and one I hope I never have to rely upon. I also wear only cotton clothing
when working with electricity because in the event of an arc flash, clothes made from synthetic
fibers can catch fire and burn more easily. As well, synthetics can melt and stick to my skin
if exposed to an arc flash. Once again, the wearing of cotton fibers is intended as a secondary
measure. I also wear gloves when I work and while these will provide another barrier, their primary
purpose is to protect me from cuts and abrasions. Any electrical shock protection they might provide
is purely secondary. Of course, I also wear safety glasses and a hard hat in my safety boots
must also have a green triangle, but this is mostly to protect me from the other physical
hazards of my trade. My number one line of defense against electrocution is to not work live.
It's not just my policy, it's the policy of my trade union and many companies I work for.
Any circuit I am working on is completely de-energized and made safe before I will work on it,
and all troubleshooting is done with my meter after that. My most common method of de-energizing
a circuit is to turn off a circuit breaker after I've removed all loads from the circuit.
De-energizing the circuit is the first step I take in making a circuit safe. My second step is
to verify the circuit is dead by using a non-contact AC voltage tester. This is a device that looks
like a fat pen and can be purchased readily by anyone at most hardware stores. I can stick the tip
safely into a receptacle or light socket, and if there's voltage present it will beep and flash.
When using a non-contact voltage tester, I always do a live dead live test. This is performed by
first testing the voltage detector on a known live circuit, then testing it on the circuit I'm going
to work on, and then testing it on a live circuit again. Even if I'm just going to change a light
fixture in my home, I will do the live dead live test with my non-contact voltage tester to make
sure there are no live wires in the box. This is important, because even if I'm sure I found the
right breaker, I might not know if there's another circuit in the box I'm working on that's fed
from a different breaker, or if a circuit becomes a backfed when de-energized due to a wiring fault.
I'm not taking any chances, and it only takes a few seconds to do a live dead live test with a
non-contact AC voltage tester. The third step I do is to perform a tag and lock out on the circuit.
This is done by placing a tag and lock out on the breaker I've switched off. First,
I select the appropriate circuit breaker lockout device for the size and type of breaker I'm
locking out. Once I've done that, I attach my padlock to which there is only one key that can
open it and no spares, along with a tag that includes my name and phone number. By law, nobody
could remove this tag except for me, and if you come across a circuit breaker with that's been
tagged and locked out, don't ever remove it because that could land you in jail.
Now, there are certain times in my trade where I'm required to work live. Often this can happen when
I have to perform extra testing on a circuit as a step in identifying a cause of an electrical
problem or for checking for performance issues. In this case, I take extra precautions by wearing
an arc flash suit. This suit includes coveralls that are specially treated with flame retardant,
a full-face shield, and a hardhat and leather gloves that are covered by rubber gloves.
These gloves need to be tested by my company on a regular basis to verify their ability to
provide their rated protection. This is about as close as I will get to the danger of
electrocution in my trade, and so I will take every precaution necessary to eliminate the risk
of electrocution. A person who understands the risks associated with electricity might decide
they can safely do their own electrical work on their home. Before doing this, I recommend checking
any homeowners insurance policy you might have, along with the laws and regulations by the
authority having jurisdiction. One of the reasons why hiring a licensed electrician can be so
expensive is because the liability insurance their company needs to pay. If an electrician does
electrical work on your home and then your house burns down, you will want to make a claim with
your insurance company. There will be an investigation into why your house burned down, and electrical
fault causes are easy for a trained fire marshal to identify. If it was caused by the builder,
your insurance company will sue them. If it was caused by licensed electrician, your insurance
company will go after that company, which is why they will have liability insurance. If you did
it yourself or the work was performed by someone who wasn't licensed, you could find your claim denied,
which means you could be stuck paying a mortgage on a house that no longer exists. In my part of the
world, a homeowner is allowed to do their own electrical work on their home, even if they're
not licensed, but they are required to get a building permit and have the work expected so that
the insurance company can go after the inspector if you ever need to make a claim. Sometimes,
a homeowner just wants to replace a light fixture, switch, or receptacle. In my part of the world,
like for like replacements are permissible to be done by the homeowner without requiring a permit
or inspection. However, there is one caveat that many people need to be aware of. In my part of
the world, you will want to make sure that whatever fixture or device you're replacing has been
certified by a recognized certification authority. This means that for me, anything that has a
CSA or underwriters lab certification stamped on it is recognized. What this means is that a testing
organization has been hired to independently test the device, so if a defect in your new light fixture
is the cause of the fire that burned your house down, your insurance company will go after the
certification authority. Naturally, this means that such products will cost more than those that
haven't been certified, but electricity is not something that someone should cheap out on.
Even my extension cords, power supplies, and coffee maker must have the CSA or UL logo
on it before I plug it into a receptacle in my home. Now, the AC adapter that came with my
PineBook Pro has no recognizable certifications associated with it, and so I will definitely not leave
that plugged in unsupervised. I also keep dry chemical fire extinguishers certified by underwriters lab
throughout my house in the event that an electrical device catches fire. One of the biggest problems
in this modern day is with smart light switches. This is a problem because of how light switches can
be wired. According to code, the neutral wire in the cable run to a switch can be used for a switch
loop if it is the return conductor. This means that, especially in older homes, the white wire
in the light switch box may not be a neutral wire. This is a problem with smart switches because
unlike a simple light switch, these are electrical devices themselves and therefore need that neutral
wire in order to work. Here in North America, we flow our neutral to ground. What this means is that
some smart home hackers have decided to use the ground wire as the neutral when one isn't available.
This will work perfectly fine, but what this has done is it has removed a layer of safety from
your home because the ground wire, which is technically called a bond jumper, is meant to carry
electricity in the case of an electrical fault safely to ground. By doing this, you will have turned
your ground conductor into a current carrying conductor, and this is throughout your home since all
bond jumpers are connected to a single point of ground, which is often a water supply pipe.
It may work without any problems, but if something goes wrong with that smart switch,
if it were to catch fire and burn your host down, the fire marshal will note that it was not
installed properly and because of this, neither the manufacturer nor the certification authority
could be held liable, even if the device can be proven to be faulty. Also, ground wires are usually
smaller than current carrying conductors because it's expected that they will carry current for a
very short period of time before a breaker trips. And now, a potential electrical fault,
shorting to ground anywhere in your home, could now backfeed your smart switch, which could cause
it to blow up and burn. For this reason, all new builds are requiring electricians to bring a
neutral wire to all switch boxes so that a homeowner can install smart switches. Another common
problem I find is when homeowners replace a light fixture with a ceiling fan. The problem
exists because most boxes used for light fixtures are not rated to support a ceiling fan. A typical
light fixture weighs very little and does not move, whereas a ceiling fan weighs considerably more
and its movements can shake a normal box loose over time. When installing a ceiling fan, I always
make sure the box is rated to support a ceiling fan. If I don't know, it's safe to assume it's not
because as I mentioned before, the contractors who build homes will not spend more than they have to.
There are boxes that are rated to support a ceiling fan, and there are ways to make a
traditional octagon box strong enough to support a ceiling fan. Not doing this adds the danger of a
heavy falling object over your head in addition to the potential of a short circuit.
Well, that's all I can think of for this podcast. I can't fit three years of trade school,
a five-year apprenticeship, and a 953-page co-book into a single podcast, but I think I touched
on the important topics to help a listener of Hacker Public Radio to understand the reasons why
everyone needs to be careful around electricity, and so I don't want to make people afraid,
just to give you the knowledge that the hazards are always present and it's up to all of us to
keep it safe. I would like to live in a world where nobody is killed by electricity because everybody
understands the risks associated with it, and this is a case where following local codes and laws
is a good idea, even if you question some of them. Oftentimes, we can come to question a code
of regulation because we lack a full understanding of the reasons why, but sometimes a rule or regulation
can be wrong, and it is our duty to call this out. For this reason, books like the Canadian
Electrical Code are written in a transparent manner, and electricians like myself can make
recommendations on future editions of the code, which is why it is updated every three years.
My trade is open to anyone showing competence and a good work ethic. There are no secret
handshakes here. Unfortunately, human nature is that we tend to forget how dangerous something can
be as we make it safer. Someone born today would be unaware of the risks of electricity as they were
100 years ago, but those risks have always been there. We just learn how to make it safe,
and we're still learning how to about ways to make it even safer. Education is key, and we all
need to do our part. Okay, so now it's time to stop being so serious and have some fun,
and for the musical portion of the Paul Quirk show, I selected a very fun piece I think you will
enjoy. This song is called In the Hall of the Mountain King, composed by Edward Grieg,
and performed by the Muse Open Symphony, and available here for you to enjoy thanks to the
Creative Commons license. Enjoy!
This episode of the Paul Quirk show, as usual, please remember to drive safe and have fun.
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