Emergency Lighting Systems for Buildings

Emergency lighting systems in buildings are rarely used, but are critical if needed. When the main power goes out, these units provide light to a safe passage. When the fire alarm bells are ringing and smoke is in the air, these backup lights save lives by helping to prevent people from panicking.

Emergency lighting is a part of a building's life safety system, and are standard in commercial, industrial and multi-family residential buildings. Emergency lighting activates when the main power is cut by fire; it provides illumination for a minimum of 30 minutes to allow the building to be evacuated.

Most times, the emergency lights are separate from exit signs, and their purpose is to:

• Illuminate the path along the exit routes, especially in hallways, office spaces and floor spaces with high occupancy levels;
• Provide a minimum level of lighting in the most populated areas of the building;
• Highlight equipment hazards and falling hazards such as stairways;
• Keep people calm when the main lights go out;
• Emphasize muster areas as people instinctively 'head towards the light' during a crisis.

Emergency lighting is required in high-occupancy residential buildings. The individual suites don't need emergency lamps, but the common areas, corridors and stairwells do.

Emergency lights are powered by a battery-backup system that switch on automatically in a power outage. Remote lamp heads use separate conductors (usually DC) from the main lighting circuits and are spread throughout the tenant space.

Most modern installations use low-power, high-output LED lamps, while the older units still use the incandescent spot lights. All units have a reflector and lens, rather than a flood light, to focus the light along a pathway.

Electrical engineering consultants design emergency lighting systems to meet the minimum requirements set out in the building code, fire code and the Canadian Electrical Code. We then customize the system to each building's unique needs, including any special hazards and path of egress.

Here's an example. In a parcel sorting plant, when the main power is interrupted, the warehouse area will be lit to a minimum level, while the areas around the conveyors will have added emergency lights to allow workers to safely evacuate away from the machinery.

In Alberta and BC, a minimum duration of of battery power is required for these systems, depending on the building designation. The emergency power source can be a battery or a backup generator.

Provincial Building Code Requirements for Emergency Lighting Systems

Provincial standards for emergency lighting systems can vary on a number of lighting issues, including:

• Average illumination level;
• Lighting for principal routes providing access to exits in open floor areas;
• Emergency lighting in service rooms. We may provide emergency lighting beyond the minimum stated duration since this is where work on the critical building systems take place;
• Corridors servicing sleeping rooms for certain types of building occupancy;
• Corridors servicing classrooms, underground walkways and public corridors;
• Floor areas of certain types of building occupancy;
• Food preparation areas in commercial kitchens;
• Additional or special requirements for health care facilities.

Backup Power

The emergency lighting equipment automatically activates upon failure of the power supply to the normal lighting circuit in the area. Multiple battery backup units should be distributed across the normal lighting circuits to allow for select operation if individual circuits fail, not necessarily just the failure of the main power source.

• Some systems have a central battery bank storage. However, it's more complicated to provide coverage for outages for local lighting circuits this way.
• Battery backup ballasts are available from manufacturers. These may be used in stairways to simplify the electrical distribution for the lighting circuits.
• The wiring for the emergency lighting circuit should be kept separate from the normal lighting. This is to prevent damage to the main lighting conductors from knocking out the emergency lights as well.
• Equipment must be mounted above the floor, according to code.
• Standards are set for how high above the floor the receptacles for battery-backed units must be mounted, and for the distance permitted from the location of the equipment.
• Permanent connections, not a receptacle, are required for units operating off of 250V or higher or if the AC current draw is more than 24 A.

Special Cases

Power outages can be frequent in some areas of the country. Depending on the outage duration and the associated risk to those in the building, engineering discretion may be used to determine the type of backup power system for the emergency lighting system. This may exceed the minimum requirements set forth in the code to ensure safety. Working with the local fire safety and building inspectors in these rare circumstances is important.

Maintenance of Emergency Lighting Systems

The building codes may require that emergency lighting systems be tested regularly to ensure they operate safely when really needed. This testing is usually done by electrical contractors and fire alarm companies.

Emergency lighting systems are essential components of a building's life safety systems. They're the last systems operating when emergency situations occur, and help to keep lives and livelihoods safer. Contact us to see how we can help with your life safety system.

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