Arc Flash Frequently Asked Questions

1. What is an Arc Flash?
2. What type of damage is rendered to equipment during an arc flash event? 
3. What are the implications for worker safety? 
4. What is NFPA 70E? 
5. Does the Canadian Electrical Code specifically address arc flash? 
6. How do I protect my workers? 
7. How can my company adopt NFPA 70E guidelines? 
8. How can Schneider Canada Services help me implement NFPA 70E? 
9. Can you conduct the Schneider Canada Services – CSA Arc Flash Electrical Safety training at our facility? 
10. When should I consider conducting an Arc Flash Study in my facility? 

What is an Arc Flash?

According to the National Fire Protection Association (NFPA), an arc flash hazard is "a dangerous condition associated with the release of energy caused by an electric arc". An arc flash is an explosion capable of causing severe burns, injuries and/or death, depending on the severity of the incident. Arcing fault current is fault current that flows through the air. This is unlike "bolted" fault current, which flows through conductors, busbars, and other equipment that is designed to withstand its effects. This current flow, through air, releases a great deal of energy in the form of heat and pressure. An "arc-flash," which refers to the uncontrolled release of such energy during an arcing fault, can result in significant damage to equipment, or worse, injury or death to workers exposed to the fault. An arc flash is caused by a reduction of the insulation or isolation distance between energized components. Incidents typically occur in applications above 120V, and can happen when electrical equipment is being serviced or inspected. Incidents can be caused by:

• A tool being inserted or dropped into a breaker or service area, or another item accidentally left behind, that compromises the distance between energized components.
• A worker mistakenly failing to ensure that the equipment has been properly de-energized. For this reason it is always best not to service energized electrical equipment.

Five to ten arc flash explosions occur in electric equipment every day in the United States, according to statistics compiled by CapSchell, Inc., a Chicago-based research and consulting firm that specializes in preventing workplace injuries and deaths.

What type of damage is rendered to equipment during an arc flash event? 

After an arc flash event, the damage can be serious enough to render the equipment no longer usable. This causes a disruption of your operation for hours or days, depending on the type of equipment, its age and how quickly service can be restored to it.

What are the implications for worker safety? 

Injuries from an arc flash event range from minor injuries to third degree burns and potential death owing to the energy released. Other than burns, a person can experience blindness, hearing loss, nerve damage, cardiac arrest and/or other related medical conditions. Revisions to the 2006 Canadian Electrical Code now specifically address arc flash hazards by referencing industry standards such as:

• National Fire Protection Association (NFPA) 70E-2004, Standard for Electrical Safety in the Workplace.
• IEEE Standard 1584, Guide for Performing Arc Flash Hazard Calculations These provide information on safe work practices and required protective equipment for electrical workers exposed to arc-flash hazards.

What is NFPA 70E? 

NFPA 70E is a worker safety standard drafted by the National Fire Protection Association (NFPA). Among other safe workplace practices, it provides awareness on arc flash hazards. The standard also gives guidelines for flash hazard analysis, which leads to choosing appropriate personal protective equipment (PPE) for worker safety.

Does the Canadian Electrical Code specifically address arc flash?

As of 2006, the Canadian Electrical Code (CEC) has been revised to address the issue of arc flash by recognizing the NFPA 70E standard as a valid workplace safety standard in Canada. Equally important is the Canadian Occupational Health and Safety Law requiring "employers to take every reasonable precaution to protect the health and safety of their workers".
Adopting the safe work practices found in NFPA 70E is a “reasonable precaution” for employers to take in order to protect the health and safety of their employees.
If an employer is found not to have taken a “reasonable precaution” in addressing arc flash issues, the law can hold individuals (rather than just the corporation) personally responsible.

How do I protect my workers?

While properly maintained equipment and safe work practices can help minimize the probability that an arcing fault might be initiated, workers potentially exposed to this hazard must still be adequately protected. An analysis of the potential arc-flash hazard at a relevant system location should be performed so that workers can select and use appropriate levels of PPE. The severity of the hazard that is related to an arcing fault is measured by the amount of energy that an arc delivers to an exposed worker. Calculation of this "incident energy," which is commonly measured in calories per square centimeter (cal/cm2) or joules per square centimeter (J/cm2), provides a basis for selection of proper PPE, including flameresistant clothing, flash suits, arc hoods, and other similar equipment. Both the incident energy and the flash-protection boundary vary, because they are based on many parameters. The most important factors include:

• System voltages Arcing fault current levelsDistance from a worker to the fault source
• Duration of the fault

The hazard level depends on many system variables, including:

• Equipment type
• Prospective bolted fault currents
• Characteristics of the upstream protective devices

It is important to use the correct level of PPE equipment for the task and the hazards that are present. Too little PPE leaves workers inadequately protected, and is therefore undesirable. Too much PPE is also undesirable, as it may hinder movement and increase the level of risk associated with a specific work task, or create other hazards such as increased heat stress.

How can my company adopt NFPA 70E guidelines? 

There are a number of steps you can follow to begin adopting the NFPA 70E guidelines. You can start by ensuring that you understand the standard and follow by instituting a comprehensive safety program with defined responsibilities.
You can then analyze and calculate arc flash incident energy for each equipment location in your facility. This is typically done through an arc flash assessment by an experienced vendor such as Schneider Canada Services.
Plant or safety managers will need to implement arc flash safety training for their employees and electricians. They will also need to update and enhance their safety procedures and manuals to comply with the NFPA 70E guidelines.

How can Schneider Canada Services help me implement NFPA 70E?

Schneider Canada Services can help you understand NFPA 70E in order to provide a safe working environment for your electricians and/or employees. As a safety-focused company, we take the lead in providing education and solutions to address changing electrical standards. To help meet the newly revised standards on arc flash, we can assist you by conducting an assessment that will provide a baseline to determine the status of the equipment in place and recommending remedial actions, if necessary, to mitigate arc flash incidents. The assessment and recommendations may include:

• Analyzing and calculating the degree of arc flash hazard.
• Type of personal protective equipment required.
• Type of training needed for workers.
• List of tools needed for safe work.
• Description of warning labels required for equipment.
• Deployment of products, solutions or methods to limit arc flash,when possible.
• Assist with specifications for new or upgrade of existing equipment .

With just a phone call, we can arrange to: 

• Give an information seminar to help you understand NFPA 70E and changes to the Canadian Electrical Code.
• Provide an assessment of your facility to determine what you must do to comply with NFPA 70E.
• Conduct an arc flash analysis to determine the incident energy levels and boundary distances. This may include a short circuit analysis.
• Provide recommendations of PPE category and labeling requirements, and interpretation of NFPA guidelines.
• Recommend changes to equipment protection settings and/or possible retrofit options to reduce arc flash incident energy levels.
• Train your employees on arc flash hazards and the use of PPE.

Can you conduct the Schneider Canada Services – CSA Arc Flash Electrical Safety training at our facility? 

Our experts can conduct customized, on-site training at your facility to educate your employees and any outside electrical contractors you use about the dangers of arc flash and how to follow the NFPA workplace safety guidelines. This training will enable your employees and contractors to:

• Realize the dangers of exposure to arc flash.
• Manage arc flash incident protection more effectively.
• Understand the different levels of PPE.
• Implement effective safety procedures.
• Choose the correct type of equipment you’ll need to work on and around your own electrical equipment.
• Conduct arc flash assessments and distance calculations

When should I consider conducting an Arc Flash Study in my facility?

If your facility meets any of the following conditions, you should consider consulting Schneider Canada Services for an arc flash analysis:

• Arc flash study has not been performed in the past three years.
• Short-circuit, protective coordination studies have not been performed in the past five years.
• Changes have occurred to the electrical distribution system or electric utility system.
• A safety audit is required.
• Your facility’s insurance policy is up for renewal.
• Modifications or expansions of the electrical distribution system are being considered.

The analysis is performed by our highly experienced team of professional engineers.

An arc flash analysis includes: PPE category recommendations presented in a clear, tabular format (Based on IEEE Standard 1584, Guide for Performing Arc Flash Hazard Calculations). Written report of findings and recommendations for reducing arc flash hazards.

- Optional power equipment labels listing PPE category recommendations for attachment to existing
enclosures.
- Optional colour-coded, single-line diagram showing PPE category recommendations for posting in electrical
rooms.
- Optional on-site electrical safety training for your staff.