 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
INTRODUCTION
OF
EMERGENCY LIGHTING SYSTEMS
We are pleased to welcome you to the concept, usage and advantages of Emergency Lighting Systems. Although emergency lighting is not a seperate subject from the other lighting of premises, a topic dealing specifically with emergency lighting is justified today because the subject is of importance to the safety, security and essential working of occupants. The number & type of emergency lights to be installed in a particualr premises depends upon the area, type of installation & its specific requirements.
Inspite of the advancements achieved in the field of electricity, constant
electricity supply can never be ensured. Power failures are bound to occur
and recur at ant time.
Emergency lighting is a vital part of any installation today. It helps
to implement a desirable safety, security ans essential services for specified
period. Emergency lighting ensures the prevention of accidental injury
and aides in a smooth functioning of essential work. It helps to locate
the exits / escape routes thereby ensuring smooth dispersal of occupants.
Emergency lighting is a vital facility to enable persons to carry on their
essential jobs even when the normal lighting has failed. Failure of the
normal lighting may occur any time. In case of fire the risk of injury
arising out of such mains failure can be very high. Emergency lighting
together with proper means of fire management, can help to reduce this
suffering and loss of life.
The failure of lighting in any premises provides an oppurtunity for crime. When the normal lighting fails, emergency lighting can serve the vital function of providing essential light at points of risk such as at cash counters, jewellery stores, strong rooms in banks and other vulnerable points. It enables vital tasks to be continued & it also helps persons to escape from premises. Emergency lighting and stand by lighting can also protect persons and property by performing a crime-prevention function. Vital services can remain in operation during a mains failure.
Emergency lighting
can be divided into four main groups :
Non maintained
Also known as standby. The lamps are not illumuninated during normal mains
supply., but are automatically energized by the integral battery in the
event of main power failure.
Maintained
The lamps are energized during normal mains supply. In the event of the
mains failure, the same lamps remains illuminated by automatically getting
switched to intergral battery source.
Sustained
Where at least two or more lamps are energized during normal mains supply
and in the event of mains power failure, one of the lamps remains illuminated
by automatically gettting switched to integral battery source.
Centralised
System
Where collective Emergency Lighting has to be energized in the case of
mains failure. The Centralised System is advisable. Centralised System
is a unit comprising of battery bank and a single power convertor which
convrets battery voltage to 230V AC. It can operate any mains operated
equipments.
The emergency lights are powered by Sealed maintainance-free rechargeable batteries.
A unit consists of :
-
Enclosure made of 22 SWG sheet steel with 9 tank powder coated process for rugged applications, some models are with ABS or polycarbonate enclosure.
- Special grade step down charging transformer.
- Glass epoxy PCB with hi-grade low-tolerance electronic components.
- Solid State switching circuit which keeps inverter 'OFF' when main supply is 'ON' and switches the inverter as soon as the power fails.
- High frequency inverter circuit which converts battery voltage in to high voltage, suitable for flourescent lamps and for noiseless operation.
- Regulated battery charger which allows quick charging of a discharged battery.
- Low battery auto
cutt-off circuit which allows the battery voltage to cutt-off at a low
level as per the battery voltage specifications. Normally 1.7V per cell
for lead acid battery & 1V per cell for
Ni-Cd battery.
Precautions to be observed for prolonged, satisfactory & efficient performance of the units :
- Keep the unit on constant AC supply. Protection against over charging is incorporated in the circuit. Consumption of power in a fully charged battery is extremely nominal in trickle charge.
- In case the main supply is switched off in the evening, the switch on the unit should necessarily be kept on 'OFF' position, otherwise the unit will be 'ON' constantly, till AC supply is restored thus reducing the life of the battery drastically.
- The unit should preferably be connected to constant AC supply which is not switched off in the evening.
- Discharge the Battery once a quarter.
- Use specified rating fuses. Using higher rating will damage the unit.
- In case of fault, do not disconnect the unit from the mains supply (i. Let the unit remain on charging.)
- Keep the unit away from heat and moisture.
All rights reserved. 1999 Professional Lighting Pvt. Limited.