Emergency Lighting System

Large stores must be fitted with an emergency lighting system, battery maintained, to enable the routes to the exits to be seen clearly in the event of a mains power failure. 

Emergency lighting systems based on electroluminescent devices... 

Use of inverter or generator back-up power for emergency lighting systems (especially for large area warehouses, where battery-powered bug-eye lights are not practical). 

Another important area of application is the use of small power units as backup power in situations of sudden loss of grid power because of natural or technical problems. Such backup units are extremely important to those consumers who cannot tolerate power interruptions. This is the case for various stationary telecommunications installations (for instance, receivers, transmitters, relay stations, signal amplifiers). Ofher users who can use unifs of fhis fype are surgery wards in hospitals, computer units in traffic control, financial insfifufions, and emergency lighting systems in public... 

Lighting Visibility is important in exiting a fire. Not only can smoke build up rapidly and obscure vision, but there may be a power interruption to building interiors. Loss of normal fighting is particularly a problem for buildings with few or no windows. The code specifies details for emergency lighting systems, which require routine maintenance to ensure they work when needed. 

Emergency Lighting System Test," DPSOL 105-1879D, Westinghouse Savannah River Company, Aiken, SC. 

Each employee undergrovmd shall have an acceptable portable hand lamp or cap lamp in his or her work area for emergency use, unless natural light or an emergency lighting system provides adequate illumination for escape. 

The nickel-cadmium battery is also used in power-generating stations and power distribution networks where power supplies must not break down. The batteries are used in switch-gear applications and for control and monitoring functions. In centralized emergency lighting systems in hospitals, public buildings, sports arenas, and schools, nickel-cadmium batteries are often specified in building codes and by consultants in many industrialized countries. 

The monitoring of emergency lighting systems needs to form part of the overall management of fire safety. 

Lead is in some types of batteries automobiles and other vehicles use lead-acid batteries, as do some alarm and emergency lighting systems (Wieman 2013). These batteries do not threaten human health when they are used. Problems occur when they are disposed of improperly. If they are landfilled or incinerated, lead can be released into the environment. Recycling is the best option for disposal of lead-acid batteries. 

To be able to advise on this the battery manufaeturer needs to know what is required in terms of eurrent output, voltage and frequeney of operation. If only one continuous load is to be supplied, sizing the battery can be simple. For example, an emergency lighting system drawing 20A for 3 h on battery power would require a 60Ah battery at the 3 h rate. Since standby batteries are conventionally rated at the 10 h rate, this is equivalent to a 75 Ah battery at the 10h rate. 

Automatic recharge is often used in emergency lighting systems. 

NFPA 101 states that testing must be conducted on every required emergency lighting system at 30-day intervals for not less than 30 seconds. An annual test shall be conducted on every required battery-powered system for not less than 1 V2 hours. 

Generally, electrical control systems are designed Fail-Safe. If power is temporarily lost, unnecessary shutdown of the process may occur. Thus, most safety systems such as fire and gas detectors, Nav-Aids, communications, and emergency lighting require standby D.C. power. 

Small-format lead-acid batteries with immobilized electrolyte are still used in some applications such as hand lanterns. Low-cost six or twelve-volt batteries (e.g. 6 Ah size) are used in child-driven toy cars and other sizes in emergency-light or alarm systems, kept on trickle-charge. Efforts are being made to produce bipolar systems which give 30 percent improvements. 

The top event is written at the top of the fault tree and is indicated as the top event (see Figure 11-14). Two events must occur for overpressuring failure of the alarm indicator and failure of the emergency shutdown system. These events must occur together so they must be connected by an AND function. The alarm indicator can fail by a failure of either pressure switch 1 or the alarm indicator light. These must be connected by OR functions. The emergency shutdown system can fail by a failure of either pressure switch 2 or the solenoid valve. These must also be connected by an OR function. The complete fault tree is shown in Figure 11-14. 

Fueled by natural gas, the 200-kW fuel cell will be a continuous source of power. The residual heat of almost 700,000 Btu per hour will be used for the shop s domestic hot water system. In case of a power disruption, the fuel cell will automatically supply electricity to the building s non-emergency lights. Combined with other sustainable green design elements, NYC Transit expects to use 36% less energy over the life of the new facility. 

Warning Device Summary Use warning devices such as radiation alarms, fire alarms, intercom systems, and emergency lighting to warn of potential hazards and identify appropriate emergency response procedures. 

Where releases of flammable or toxic chemicals are possible, a flammable or toxic gas alarm system is often established as part of the plant emergency alarm system. Best practices require different types of alarms to be annunciated differently, both audibly and visually. For example, the toxic alarm stations may be provided with a blue light to distinguish them from fire alarm stations that are red. A consistent color system for lights should be adopted. 

Portable valve-regulated lead-acid cells can operate in any orientation without acid leakage and find use in many different applications, such as in electronic cash registers, alarm systems, emergency lighting unit equipment, telephone boxes, switching stations, minicomputers and terminals, electronically controlled petrol pumps, cordless television sets and portable instruments and tools. 

Iron-nickel oxide batteries have been used for many years in railway lighting applications, and for motive power in industrial trucks, tractors and mine locomotives. There is some utilization of the system in emergency lighting and alarm circuits. 

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