Emergency Lighting Principles: Safety and Security on the Path of Egress

Emergency Lighting

Sept 16, 2019

By Kevin Smee, Vice President Sales at AimLite

Most of us take light for granted. It has become so ubiquitous and cheap to use that we don’t really stop to think about emergencies. Thankfully most buildings are required by law since 1974 to be equipped with emergency lighting that automatically activates during power failures to facilitate our exit.

Emergency lighting is only one component of a building’s life safety systems, but perhaps one of the most important. It provides a minimum level of visibility to help direct the building’s occupants safely out of it. Moreover, it also helps personnel and emergency responders locate safety equipment, perform safety functions, or shut down hazardous equipment or operations.

Requirements for emergency lighting differ from facility to facility, but we will attempt to shed some light on the subject so you can better be acquainted with the emergency lighting category.

About emergency lighting

An emergency light is, in its most simple definition, a battery-backed lighting device that switches on automatically when a building experiences a power outage or when a lighting circuit fails.

Emergency lighting is mandated by federal, provincial and/or association codes and criteria. These are borne out of those collective governing bodies’ desire to achieve safety and security on the path of egress, in residential, commercial and industrial areas.

Path of egress refers to a continuous and unobstructed way to exit a building, structure or space. Buildings or portions of buildings thereof must, in accordance with various safety codes, have a sufficient amount of lighting on paths of egress. These must be maintained and well lit in the random event of an emergency. The lighting used in these emergency exit paths must also fit certain codes.

Emergency lighting other than emergency signs must provide an average level of illumination of 10 lx or 1 foot candle and cannot be less than 1 lx or .1 foot candles (luminous flux per unit area) at floor or tread level in places such as exit ways, principal exit routes, corridors serving the public, underground walkways, and more.

How does emergency lighting work?

When power is lost, AC power is therefore lost, so the backup battery unit turns on and transfers power to the lighting system (this is called DC power). When AC power is restored, the emergency lighting batteries must be fully charged within 24 hours.

The National Fire Code of Canada (FCC) requires that emergency lighting be tested for one minute each month and once a year a full discharge for 30 minutes (repeated 24 hours later)

The reason is simple, cyclic operation is required for all batteries; otherwise it will probably not work when the time comes. It’s proven that non cycled batteries have a lifespan of no more than 3 years, whereas regularly cycled batteries have a minimum lifespan of 7 years. Most battery units can comprise an auto-test function to facilitate meeting code requirement. The 30-minute discharge test is intended to simulate an emergency situation in accordance with FCC requirements. The second 30-minute discharge test performed 24 hours later aims to ensure that the product is ready in case of power failure CSA requires all emergency power supplies to be fully charged in less than 24 hours.

About exit signs

An exit sign is a device used in any public facility and denotes the location of the closest emergency exit in case of a fire or other emergency. It has to be powered, show the exit direct, and can be mounted in various ways depending on preferences or location (ceiling mounting, recessed mounting, end mounting, wall mounting or pendant mounting).

There are different types of emergency exit signs, depending on environment and application.

Electrical signs include:

• Running Man
• Exit
• Exit-Sortie
• Sortie

Non-electrical signs include:

• photo-luminescent signs
• tritium (radio luminescent) signs

Currently, new constructions are required by code to install the new green running man signs, consisting of a green and white pictogram and arrow, which display the direction of the exit. Older constructions are required to gradually update the old red exit text signs to the running man ones, to conform to the 2015 National Building Code.

Every exit sign must be visible from a distance of 100 feet and on approach of the exit. It can be internally or externally illuminated, in conformance with their respective codes. Internally illuminated signs are powered by an electrical circuit. Externally illuminated signs are not powered by an electrical circuit, but by regular luminaires and must maintain 5’ candle per legend 24/7.

The breaker serving emergency signs cannot light anything else but the sign it was wired for. It must also be connected to an emergency power supply at all times and remain on even when there is no AC power failure. In short signs must be on a dedicated breaker.

AC/DC

No, we’re not referring to the 80s band! AC/DC refers to the current that powers the emergency light.

The abbreviations are defined as follows:

• AC = alternating current (hydro)

• DC = direct current (batteries)

Alternating current (AC) is an electric current that periodically reverses direction, in contrast to direct current (DC) which flows only in one direction. Alternating current is the form in which electric power is delivered to businesses and residences, and it is the form of electrical energy that consumers typically use when they plug kitchen appliances, televisions, fans and electric lamps into a wall socket.

Direct current (DC) is constantly self-powered, such as with a battery, so that the current (voltage) is always constant, with no dips or spikes.

Normally on/off

• “Normally on” means the unit is on all the time, 24/7. It is active when AC power is present or when DC power kicks in. Exit signs are always “normally on”.

• “Normally off” means the unit is off when AC power is running, but turns on when DC power kicks in. Remote heads are usually “normally off”.

Types of emergency lighting 

Traditional: battery units utilizing sealed lead batteries in various configurations to give 6vdc, 12vdc or 24vdc output to normally off remote heads when AC power is lost to the panel they are connected to. 

Battery packs will operate to a maximum of 120 minutes to the minimum required by code of 30 minutes.

Inverters: there are two types:

• IPS interruptible power supply… in short standby system non instant transfer

• UPS Inverters uninterruptible power supply… in short no break load. Maintains 1 cycle of load 24/7 unnoticeable transfer

Both types work off of batteries IPS (mini inverters up to 1440w), utilize a 12vdc or 24vdc battery source, and convert to 120vac for a minimum of 30 minutes with one single circuit allowing regular luminaires to be lit 100% normally on and during a power failure.

UPS Inverters work utilizing 10 12vdc batteries in series to handle normally on loads up to 55kw in single phase or 3 phase applications (loads may vary pending on which phase using).

Inverters are a continuous AC supply and are a single point of service for large commercial, industrial and institutional projects.

To learn more about our inverters, check our Inverters Brochure.

Generators: no batteries required but a backup of diesel or propane tanks are needed to fuel this standby system, which will back up critical lighting and signage in case of a power outage.

The transfer time varies on these 120v or 347v systems but normally is 10-16 seconds pending on loads and age of systems.

These systems are generally used in large condos and industrial jobs.

In conclusion

As we’ve seen, there are many things that make the emergency lighting category particular. We looked at emergency light principles and codes, how it functions, the exit signs subcategory (including electrical and non-electrical signs), and what AC/DC and normally on/off mean. We hope we were able to enlighten you on the subject and that it will help you on your next emergency lighting project.

Kevin Smee, Vice President Sales, AimLite Canada

 

Related Articles


Latest Articles

  • Video: LEDVANCE Lightpoint Learning Facility

    Video: LEDVANCE Lightpoint Learning Facility

    February 23, 2024 LIGHTPOINT Studio & Showroom, the brand-new corporate classroom training facility, located at their national customer service and sales center (NCSSC) in Westfield, IN. Go HERE for more information Read More…

  • How Effective Communication Reduces Plant Hazards

    How Effective Communication Reduces Plant Hazards

    February 23, 2024 By Rick Farrell, President, PlantTours In plant operations, the margin for error is notoriously slim. The smallest oversight, a single misinterpreted instruction, or an unnoticed alert can be the difference between smooth operations and catastrophic failures. While advanced technologies and protocols play an undeniable part in ensuring safety, the bedrock upon which… Read More…

  • A Guide To The Most Essential Hand Tools for Electricians

    A Guide To The Most Essential Hand Tools for Electricians

    February 22, 2024 By Jonard Tools It is currently a great time to be an electrician- however, you’ll need the right hand tools for the job. In this article Jonard Tools highlight the most essential hand tools for electrical work, as well as dive into the specifics of how they are utilized and why they’re… Read More…

  • New Research on Smart Home Technology and Market Trends

    New Research on Smart Home Technology and Market Trends

    February 22, 2024 AI-driven features in home energy management and security systems excite more than half of the current smart home users, concludes new research exploring the perceptions, preferences, and reservations of residential renters and owners regarding the adoption and usage of smart home technologies. However, the survey also highlights data privacy concerns and high… Read More…


Changing Scene

  • LEDVANCE Canada Welcomes Cristiano Konofal as National Account Manager

    LEDVANCE Canada Welcomes Cristiano Konofal as National Account Manager

    February 26, 2024 LEDVANCE Canada has introduced Cristiano Konofal as their National Account Manager. “I am thrilled to announce the return of Cristiano Konofal as a National Account Manager. Cristiano has extensive experience working with our customer base and has technical skills that will be an asset to our team. We look forward to seeing… Read More…

  • Government of Canada Invests in TDG Transit Design Group

    Government of Canada Invests in TDG Transit Design Group

    February 23, 2024 The Governemnt of Canada has announced a FedDev Ontario investment of over $1.6 million for TDG Transit Design Group, a manufacturer and designer of made-in-Canada, energy-efficient LED lighting systems for the global rail transit industry. Through this investment, TDG Transit Design Group will adopt new equipment at its newly expanded 10,000-square-foot facility… Read More…

  • Alberta to Invest in Apprenticeship Seats Through 2024 Budget

    Alberta to Invest in Apprenticeship Seats Through 2024 Budget

    February 23, 2024 Through their Budget 2024, Alberta’s government would invest an additional $24 million per year over the next three years to create 3,200 apprenticeship seats at 11 post-secondary institutions across the province. The new investment would bring the total funding through the Apprenticeship Learning Grant for the 2024-25 academic year to $78 million…. Read More…

  • PataBid and City Electric Supply Introduce Estimating Software Promotion

    PataBid and City Electric Supply Introduce Estimating Software Promotion

    February 23, 2024  City Electric Supply Corporation CA and PataBid have joined forces to offer our mutual customers an exclusive discount on Quantify electrical estimating software.  Sign up for a free trial and link your CES account to your PataBid Quantify account to unlock this special offer. If you’re not registered with CES yet, drop by… Read More…