Our Articles on Electrical Safety

Electrical Safety Program Requirements in Canada

Jeff MacKinnon · May 9, 2019 · Leave a Comment

Something that I have been thinking about lately is: What are the electrical safety program requirements in Canada.

OSHA covers all of the USA, and the minimum Electrical Safety Program requirements can be found here – 1910 Subpart S.

In Canada, the Canada Occupational Health and Safety Regulations, part VIII mentions written procedures a couple of times, but not very clear if this needs to be an electrical safety program, or just a couple of written checklists.

“the employer shall issue written instructions with respect to the procedures to be followed for the safe performance of that work”
from Canada Occupational Health and Safety Regulations

How about the provinces?

The rest of this article will have the various provincial regulations to find out what they say, and how clear they are regarding the requirement of an electrical safety program.

Newfoundland and Labrador

The Occupational Health and Safety Regulations in NL are pretty clear in the assumption that the employer has an electrical safety program in place. They mention it by name in two different places:

Low voltage electrical equipment – 482(2)
- “Where it is not practicable to completely disconnect low voltage electrical equipment, work shall be performed in accordance with an electrical safety program in accordance with a standard acceptable to the minister that… “
Isolation and Lockout – 490(2)
- “Where it is not practicable to completely isolate high voltage electrical equipment an employer shall conduct a formal hazard assessment and develop an electrical safety program that…”

From the NL Occupational Health and Safety Regulations

Newfoundland and Labrador appears to be very clear that they expect employers that interact with electrical equipment to have an electrical safety program. They mention it by name in two places, both having to do with the isolation of electrical equipment.

In section 484(2)(e) they even mention that current diagrams are required. These diagrams, in my opinion, don’t just include the single line, but all control and protection infromation for the equipment. Many times the wiring and schematic diagrams for control panels are not updated after changes.

Nova Scotia

The Nova Scotia Occupational Safety General Regulations Part 11 covers electrical safety, but they don’t mention an electrical safety program specically. In fact, the NS regulations are written in a fashion that makes it seem that working on energized equipment below 750V is NOT hazardous work. You read that correctly. Here is the quote from subsection 125(2)

125 (2) An employer shall ensure that no work is performed on an energized electrical installation rated at greater than 750 v phase to phase unless the competent person performing the work is accompanied by another competent person.
From NS Occupational Safety General Regulations on May 9, 2019

This is crazy! CSA Z462-2018 uses 30V as the threshold for whether the shock hazard exists, and if a shock hazard exists mitigation techniques need to be implemented to lower the risk. The shock protection boundaries start in at 30V in tables 1A and 1B. The only limiting distances mentioned in the NS regulations are for overhead lines, and they start at 750V.

From NS Occupational Safety General Regulations – Subsection 126(4), retrieved May 9, 2019

Prior to the 2018 version of CSA Z462, the threshold voltage was 50V, it was lowered to 30V; the 750V threshold that is implied to be a part of “Hazardous Work” is way too high. Wow.

I’m not done yet.

I have the two provinces that I do the majority of my work in covered. More to come as time allows.

Checklists

Jeff MacKinnon · Feb 15, 2019 · Leave a Comment

Today I’m starting a new-ish feature where I’m publishing a different thought as a twitter audio at least, and maybe a video depending on where I’m located.

This first thought is on checklists, and their importance in every electrical safety program. This came to me, again, when I was meeting with a client and they were getting started developing their electrical safety program. I was there to help them with an arc flash analysis update, and we started talking about the minimum viable electrical safety program.

Some background

To get there, I had to fly and I noticed something that I see every time I fly, but I haven’t thought about in a while, the pilots were doing their checklist. This was a short flight, and these pilots must do the same routine pretty much every day. They know it in and out, but the checklist helps them consiously go through all the steps every time. Its like if you drive the same part of raod often and then one day completely forget drviing it as you go though. You don’t want to space out on routine tasks.

This is where the checklist comes in, with a very routine task you may skip over steps, but with a checklist you make the check as you go through, mentally remembering to do that thing. I recommend that checklists be used for all tasks that are high risk starting out, and then add in non-routine medium risk tasks as the electrical safety program matures. An example of a medium risk task may be changing a 347V ballast at height.

Minimum Viable Checklists

The two checklists that ever electrical safety program should have are:

Energized Electrical Work Permit
Lock-Out-Tag-Out

These checklists allow the worker and manager to manage the hazards associated by those tasks, which are always medium-high risk, to make sure that everyone stays safe.

https://vimeo.com/317462033/

Let me know what you think about this first Daily Musings. If you want to see or hear it live follow me on Twitter and Linkedin. For now I will at least do a live audio to Twitter and maybe a video on Linkedin in the future.

How to Read Arc Flash Labels and Determine PPE Requirements

Cole Ferguson · Oct 6, 2016 · Leave a Comment

You need to understand warning labels to choose proper PPE.

In order to protect yourself and workers in your facility, it is important that everyone is aware of how to read arc flash labels. Being able to read arc flash labels is crucial for management in determining PPE requirements, and is crucial for both electrical and non-electrical workers to determine whether or not they currently have appropriate PPE for the task at hand.

Arc Flash Labels

First, let’s take a look at a typical Arc Flash Warning Label.

CSA 462 Arc Flash Label — Example of a CSAZ462 compliant label

There are two important pieces of information about arc flash here that determine the PPE requirement. The first is the Flash Hazard Boundary. This is the minimum working distance where appropriate PPE for energized work will effectively protect personnel against arc flash hazards. Working any closer than the minimum distance specified in the Flash Hazard Boundary can result in serious harm in the case of an arc flash incident because the PPE recommended by the label will not protect a worker from the effects of arc flash.
Next, you’ve got the energy level of cal/cm square, with a flash hazard at 18 inches. In this case the energy level is 3 cal/cm square. This is the most important piece of information on the warning label: it tells you how severe a potential arc flash incident could be. This number is determined by an incident energy study.

PPE Selection Using Incident Energy Levels

With these two pieces of information, you can now select your PPE. PPE categories are not rigorously defined by any standards organization: the level of PPE required for a particular job is defined by the facility management. CSA Z462 recommends three different levels of PPE depending on the the incident energy level:

Incident energy levels less than 1.2 cal/cm square
Incident energy levels between 1.2 and 12 cal/cm square
Incident energy levels greater than 12 cal/cm square

Level 1 PPE could be anything that covers exposed skin, hearing protection, insulated gloves and shoes, and eye protection. Level 2 PPE would be similar, except that all of the clothing has to be arc rated. Level 3 generally requires arc flash suits and other bulky PPE.
However, there are no hard and fast rules for determining PPE, just helpful guidelines. PPE categories for your facility should be heavily influenced by your Electrical Safety Program.

Just because you're covered doesn't necessarily mean you're safe — Just because you’re covered doesn’t necessarily mean you’re safe

PPE is ALWAYS the Last Line of Defence!

Remember than PPE is supposed to be the last line of defence against arc flash and shock hazards. Your electrical safety program should consider the Hierarchy of Hazard Mitigation Controls. They are:

This hierarchy of mitigation controls should always be followed to effectively reduce the risk of an arc flash hazard occuring.

The Ability to Absorb Risk is Important

PPE levels are also determined by the amount of risk that your company is willing to absorb. Statistics gathered by the NFPA show that the average electrical accident costs $80,023.This cost includes both workers’ compensation (medical bills and wages while unable to work) as well as equipment costs.
If it is more expensive to purchase and maintain PPE than it is to allow for electrical accidents, then you need to look in to the other controls that can be used to mitigate arc flash hazards. Your electrical safety program should outline the process to follow if you cannot provide higher levels of PPE (but can use other controls to lower incident energy levels on the work site). Overall, your electrical safety program and your ability to absorb risk will determine how the PPE levels are developed for your company.

First and Foremost, Your Goal Should Always be to Keep Your Workers Safe!

You can find out more about using PPE to mitigate arc flash hazards here.
As always, thanks for reading!
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What is Arc Flash

Cole Ferguson · Aug 10, 2016 · Leave a Comment

There are really only two types of electrical hazards: shock and arc flash. CSA Z462 gives a short definition for arc flash:

Arc flash hazard – a dangerous condition associated with the possible release of energy caused by an electrical arc. Arc flash takes two forms:
- Arc blast refers to the pressure wave created during an arc flash incident. This pressure wave can throw molten metal at you at very high speeds in addition to causing physical harm like concussions.
- Arc burn refers to the incredibly high temperature in the area around an arc flash. This temperature can be hotter than the surface of the sun and can cause debilitating burn injuries if you aren’t wearing appropriate PPE.

CSA Z462 mentions that under normal operating conditions, most equipment is not likely to cause an arc flash hazard. It then points to Table 4A for examples of activities with potential for causing an arc flash hazard. Because of the severity of arc flash incidents, it is very important that you understand what it is and how it can harm you.

Arc Flash Causes

An electrical arc occurs when current passes through the air from one conductor to another. A lightning strike could be considered an arc from the clouds to the ground. An arc fault occurs when you have unwanted arcing in your electrical system. This could be because of a breakdown in wire resistance, for example, due to heat. Arc faults can also occur during switching: current cannot immediately drop to zero, so some of the current arcs across the gap as a switch is opened. Undesired arc faults can damage your electrical system.

Arc flash is a severe case of arc fault. In high voltage systems, when an arc occurs it usually burns out and destroys the physical conductors, so air is the only conductor left. Air is normally an excellent insulator, but will break down to plasma when the ratio of voltage to arc length is relatively large.

Arc Flash Effects

A high voltage arc in a small space will have a very large electric field and will cause the air to break down in to plasma. This plasma will use up all of the energy available to it before it dissipates. The plasma will create temperatures as hot as 35,000 degrees Fahrenheit (Clark, n.d.) which is hotter than the surface of the sun!
When an arc flash occurs, temperatures can climb so high that it can burn the skin right off of you! Not only that, but these temperatures tend to vaporize any nearby metals (such as the ones used to make the conductors themselves). When copper (a common wire material) is vaporized, it suddenly expands to 67, 000 times its original volume. (Ray A. Jones, 2000)

Here’s a quick example using one foot of AWG 10 wire. AWG 10 wire has a conductor diameter of 0.1019 inches. (Wire Gauge and Current Limits Including Skin Depth and Strength, n.d.) A one foot long piece of AWG 10 wire has a volume of 1.80271*10^-5 cubic feet ((0.1019²/4) * 12 inches * 1 cubic foot / 1728 cubic inches). That seems pretty small. But when it gets vaporized during an arc flash, it suddenly takes up a space of 1.21 cubic feet! Now consider that a cable can be made up of multiple wires: A typical arc flash packs the same explosive power as dynamite (caused by the superheated metal as it expands into vapor). This explosive action is known as arc blast. If the force of the arc blast doesn’t kill you, you are at serious risk for broken bones and organ damage, especially if the explosion knocks you into a hard surface. It’s even more dangerous if you’re working at a high elevation: the arc blast could knock you off a solid foothold and put you at serious risk for fall injury.
Not only does the arc blast cause a pressure wave that can throw you around with a large amount of force, but it will also throw around any metal that didn’t get vaporized during the arc flash. Usually so hot that it becomes molten metal, this can burn through clothing as well as any equipment nearby and can cause serious harm to anything it touches. The explosion and high temperatures could also cause damage to or destroy nearby electrical equipment that is not part of the initial arc flash incident.
Overall, arc flash is a great risk to both people and equipment, and can result in very costly injuries to people or damage to equipment. The risk of an arc flash incident can be reduced by appropriate electrical safety program usage. In order to account for arc flash in an electrical safety program, an arc flash study is required.
As always, thanks for reading!
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Arc Flash Mitigation techniques – PPE

Cole Ferguson · Aug 3, 2016 · Leave a Comment

PPE is the last line of defense when it comes to arc flash mitigation, according to the hierarchy of hazard mitigation. Appropriate PPE selection is important to prevent introducing new risks to workers on job sites.

Safe PPE Selection

In order to select PPE, you first need to have an incident energy study on your workplace. PPE levels are determined based on the incident energy levels of the equipment being worked on, so you can not appropriately select PPE without an incident energy study. CSA-Z462 has a table that matches types of PPE to arc flash incident energy levels. This table is an excellent guide to use when selecting your PPE.

Is this worker wearing all the appropriate PPE for his job?

I personally do not recommend doing work on anything with an incident energy level higher than 40 cal per square centimeter: when incident energy is that high, you should figure out a way to reduce the incident energy level before assigning any work. All PPE should be appropriately labelled so that you know what is acceptable to wear for the present work conditions. At minimum, when working on a system with an arc flash risk, you should be wearing arc rated long sleeve shirts, pants, and undergarments, insulated leather or rubber gloves and boots, eye, face, and ear protection, and a hard hat.

Other Factors that Influence PPE Selection

Other factors to consider when selecting PPE include the working environment and the amount of time it will take to complete the job. Higher levels of incident energy require more bulky PPE. Bulky arc flash suits can impede a worker’s vision, hearing, and mobility. The large, sealed, bulky clothing is cumbersome and also gets hot quickly, which causes increased levels of fatigue. All of these things can lead to new risks that might actually increase the danger to workers on site, which is the opposite of what arc flash mitigation techniques are supposed to do!
One last thing to be sure of is that your PPE is in good repair. Old, worn out PPE full of holes won’t protect you in the event of an arc flash incident, and should not be worn by anyone.

Job Planning

Sometimes it is necessary to do work in heavy, uncomfortable PPE.

You don’t want to be stuck wearing this for too long if you don’t have to be.

When this is the case, it is important that jobs be planned appropriately to reduce risk involved. If fatigue is an issue, schedule multiple people working on the same job in short shifts as opposed to having one person doing all of the work. The buddy system (having at least two people working on the same job) also has the added benefit of safety: the second person can immediately respond if something goes wrong while the first person is working.
You can also assess the functions of the equipment being worked on to see if you can’t reschedule work for a period when the equipment can be de-energized, avoiding the need for the bigger arc flash suits.
Worker training is very important. The NFPA notes that many workers who suffer electrical injury have insufficient training and do not properly use their PPE. Training personnel to appropriately assess hazards and risks is very important because these hazards and risks influence the level of PPE required for a job. All workers should be properly trained in the use of all PPE required for a job: if you aren’t using the PPE properly, then it won’t protect you. Once again, this goes against our goal of arc flash mitigation!

Closing

When selecting PPE, you need to know the incident energy on the equipment you are working on. You then need to make sure the labels on your PPE are appropriate for the work and that your PPE is in good repair. When doing energized work, first try to reduce the incident energy levels to avoid having to wear the bulkier PPE. If that isn’t possible, have multiple people working in short shifts to avoid fatigue, or reschedule to a time when you can de-energize the system. Make sure that all employees are trained in the selection and use of PPE.
Stay safe, and as always, thanks for reading!
If you like this post but want some actionable advice, tips and information, check out our newsletter. You can sign up here or below.
By signing up you get a free report on what an Electrical Safety Program is, and how to go about building one at your facility.