Emergency lighting is usually backed by batteries and used in a power outage to allow people to exit the building safely. They’re required in high occupancy residential buildings (such as college dorms) as well as new commercial buildings. Also now, according to building codes, it’s required in some older buildings for them to be installed.
History of Emergency Lighting
In the past, emergency lights were used when the power was off and were fueled by a battery or generator. They used to use incandescent light bulbs. This changed though because it was discovered that brighter lights that would last longer were needed. Therefore, now halogen floodlights (wide-coverage) are used. They could be compared to an automobile headlight. Back in the day, emergency lights used lead acid batteries to give them a 120 volt charge. These old fixtures were rare as they were big, expensive, and heavy. As time went on, the voltage requirements for such fixtures dropped and batteries and lights got smaller. Now, the fixtures are about as large as the bulb in them and the battery easily fits in the base of said fixture.
Modern Installs
New fixtures use one or more incandescent bulbs or LEDs. Emergency lighting heads are usually PAR 36 sealed beams or wedge based lamps. Each fixture has some way of focusing and intensifying the light. This is done with a plastic cover over the fixture or a reflector behind the light source. In addition, individual light sources can easily be rotated and aimed in the direction of exits.
Each fixture is equipped with a test button that enables it to run on battery power instead of the normal power source. It’s good to check and make sure they’re functioning correctly and will work in an emergency situation. US fire safety codes state that these fixtures must run for 90 minutes on battery power during an outage and must be along the exit path. If an emergency light is staying on and you need to shut it off, try pushing the reset button on the side. It will stay on until you turn it off. Different cities have different regulations for emergency lighting and exit signs, however, there are strict requirements that there must be an average of one foot candle of light along paths of egress.
Modern emergency lights usually have a pretty low voltage (6-12 volts), which means they put less of a load on the circuit they’re part of and can use smaller batteries. A transformer inside the fixture converts the higher voltage to the low voltage that the lights need to work. The batteries used by these lights are lead-calcium and can last 10+ years on constant charge.
In recent years, there has been less usage of traditional two-head units. Instead, lighting designers, architects, and contractors use battery backup ballasts that are connected to the normal fixtures as emergency lighting. This meets NFPA’s Life Safety Code and the national Electric Code without wiring separate circuits or external wall mounts. It also looks better as all you have are the usual fixtures that fit in with the design of the room.
Codes of practice for remote mounted emergency lighting usually say that the wiring from the central power source must be separate from other wiring as well as fire resistant.
Why Should I Get Emergency Lighting?
Often referred to as egress lighting, emergency fixtures are used in power outages to light the way out of a building, helping people to safety. They’re used in conjunction with exit signs. These types of fixtures and signs are often overlooked until there’s an emergency and they are needed. If you don’t have them installed, injuries and fines may occur. Occupational Safety and Health Association (OSHA) can give fines from $7,000 (the first time) to $70,000 (for a repeat) in these situations.
What Should I Do To Make My Building Safe?
1. Light Exit Paths Adequately
People with normal vision should be able to see in the lighting. It should turn on within 10 seconds of the power turning off and should run for an hour and a half. Not only when a building is finished, but also during constructions, repairs, etc., have glowing signs installed that indicate the exits. Illuminate the area leading up to it, the actual exit, and the area outside of it. Other areas that should be lit are stairwells, corridors, hallways, and lobbies.
2. Post Signage Around the Building
Post signs that show the direction of the closest exit. Indicate what other doors and hallways are that may be mistaken as a way out. Exits must be marked with a sign that’s lit up, able to be seen, and works well in a power outage.
3. Be Sure To Have Regular Inspections
Properly maintain your emergency light and exit signs to reduce the risk of liability leading to fines, injuries, and lawsuits. The requirements mostly are a quick visual check of the exterior and a battery test. However, regulations call for a more thorough inspection yearly. This will examine the tightness and cleanliness of battery terminals, measure the “float voltage” (constant voltage applied steadily to a battery cell), and perform a battery-load test that stimulates the unit for 90 minutes on battery backup. Also, it’s good to keep in mind that batteries and light bulbs will need to be replaced from time to time.
4. Document The Inspections You Have Done
Document all the annual and monthly inspections that are done. This will prove you were on top of it and will reduce liability. (You’ll want to keep all these files together in a place that is easy to access.) A certified technician should provide documentation stating the unit they tested, the date of the service, type of service that was performed, and their name to certify that the work was done.