Lighting Services Blog

There are many older type exit signs in use today that have both D.C. lamps which are powered by a battery, that operate in the emergency mode when a power failure occurs. However, NFPA 70: National Electrical Code requires exit signs to be illuminated when, either externally or internally, twenty-four hours per day in order to identify a means of egress.

How many times have you had to repair or replace emergency exit signs due to damage, malicious mischief or vandalism? There is an answer. The “flexible” exit sign will solve nearly 100% of your problems. These replacement units are high impact injection molded ABS plastic and ready to mount to a junction box. The exit pivots from the ceiling, mounted on the wall or mount in just about any other position. The unit is virtually indestructible. We have used this unit in many school systems and high-traffic areas with great success. These U.L. listed units come with a solid state charger, long-life NiCad battery and energy-saving LEDs in addition to many other optional features such as fire alarm interface, flashing mode, tamper-proof screws, remote test actuator, damp locations, etc. The units are available with green or red letters and more importantly, in the emergency mode they will remain lit for four hours, which exceeds the ninety minute fire code requirement by two and one-half hours.

Over the last few decades there were many 32v D.C & 36v D.C. central emergency lighting systems manufactured by Dual-Lite, Light Alarms, Chloride and others.

Not totally true… Wet type emergency lighting batteries always consume some of the electrolyte (sulfuric acid for lead and potassium hydroxide for nickel cadmium) when they are being charged. The need to refill is based on age, ambient temperature, charge rate, etc. and the established monitoring of properly maintained levels of liquid. The charging process normally produces a flammable gas mixture of hydrogen and oxygen. A short circuit, open flame or smoking during must be avoided when adding water to keep the fluid above the plates or the battery manufacturer’s indicated max fill level. Some maintenance free batteries that use calcium instead of lead require less maintenance because of the greater reservoir capacity. Adding distilled water where and when possible will greatly increase the life of these “so called” maintenance free batteries.

The National Electrical Manufacturers Association (NEMA) sets the standard for various electrical products including certain types of emergency lighting and exit signs. General specifications are as follow. The NEMA for emergency lighting is designed to withstand elements that would interfere with the normal and efficient operation of the emergency lighting unit such as wet locations, rain, and snow. The lighting heads themselves are design to be waterproof as well. The units normally come in 6 and 12v and carry D.C. lighting loads up to zero watts. Input various A.C. voltages can be requested from many many manufacturers. All units have a 90 minute run-time but can be customized for runs exceeding 1.5 hours. Most units are made of high-impact reinforced fiberglass and are extremely rugged. Most units come with a 12v 36 watt sealed lead calcium battery capable of powering remote fixtures. A number of options for this unit may be requested such as volt meter, time delays, etc. This emergency lighting is more costly than your standard units but are mandatory for specific applications.

In many of the older, wet-type (lead antimony) batteries, they are shipped with a liquid installed called sulfuric acid.  This electrolyte is energized during the charging process to maintain the proper voltage in the battery.

Emergency Lighting System batteries are like spark plugs.  At 30 or 40 thousand miles, would you just change one defective spark plug?  No.  You will probably change them all because most likely they have the same mileage on them.  Banks of batteries in large AC or DC emergency lighting systems are quite similar.  When one battery fails, the balance is not far behind.  As with the spark plugs in your vehicle, the replacement of all the batteries at the same time, when one fails is, in the long run, much more cost effective.  A major portion of the cost to perform either of the above-mentioned tasks includes travel, labor, shop time, disposal of old material, etc.  Drive to the auto repair shop 4, 6, or 8 times to replace one park plug or replace and dispose of 6, 12, 20 or more batteries one at a time versus replacing all your plugs or batteries at one time is much less costly.

You've heard about "emergency lighting," but what do you REALLY need to know?

1. Emergency lighting is required by the NFPA Fire Code whether your facility is located in Connecticut or any other state.
2. Emergency lighting is sometimes called emergency "egress" lighting and is required to be present and operable within your facility.
3. The NFPA requirements call for a monthly 30-second tests to be sure that the battery keeps the lamps lit brightly to ensure safe egress in the event of a power outage or other emergency. By just pushing the test button for a few seconds you are not testing the strength of the battery back-up power.
4. The NFPA requirements call for an annual 90 minute full-load-test to insure all of your emergency lighting systems will opperate for a full 1.5 hours in the event of an extended emergency.
5. Emergency lighting can be provided within overhead lighting fixtures (such as a flourscent power packs or floursecent emergency packs), individual wall-mounted units (as part of an exit sign, or separate "two-headed" units), or as part of a central emergency lighting system (32v DC system, inverter, or generator).
6. The different types of emergency lighting require different steps by which to follow to complete the testing properly.
7. Regardless of the type of emergency lighting your facility has, it must be inspected regularly to meet fire code requirements and insure you are prepared for a life-safety emergency.