What is Fire Fighting? What are the Precautions against fire in Telecom Building?
Explain Fire Fighting in Telecom Buildings. What action to be taken in the event of fire Procedure during office hours? What are the main types of Fire extinguishers? How many types of Foam?
What are the Maintenance Instructions of Fire extinguishers?
Telecom equipment is energized from supplies derived from public AC mains or departmental engine alternator. Fire may be caused by use of higher rating fuse for circuit currents of longer intensity than the rated capacity flowing through wires or appliances, sparking due to loose contacts at certain points in the electric circuits. It can also be caused due to over load when high current cause over heating of conductors, wires coming into contact with one another and causing short circuit or wires getting earthed due to insulation of wires getting damaged. Smoking in office, equipment room, and power room. Cable chambers, battery room, throwing of burning cigarette bits, due to storage of inflammable material without proper precautions may also cause fire.
- Triangle of fire
2.1 We shall at this stage have a look at the triangle of combustion. The three essential factors for a fire are
- The combustible material or fuel
- Oxygen or air
- The ignition temperature or heat.
If any of above factors is missing, there can be no fire. The methods of extinguishing fire, therefore is reduced to
- Removal of the fuel or starvation
- Removal of the oxygen or smothering
- Bringing down the temperature or cooling.
- Fire, like heat is spread by condition, convection and radiation. Conduction means transmission through solids, convection through fluids while radiation requires no medium of transmission. All direct flames and flying sparks can also be included under the terms radiation and these account for the majority of equipment fires in the department. A careful watch is very essential to prevent such fires.
- Throwing quantities of cold water effectively quenches majority of fires. A pump is a handy device and a party of three or four trained persons can with this appliance, effectively put out even a major conflagration. Water can, however, not be used over oil fires and electrical fire fused in the case of oil fires, oil being lighter will be spread out and the water sinking to the bottom gets heated up flashes into steam and consequently expanding to about 1700 times, foams over with violent eruption. In the case of electrical fires, use of water on live electrical equipment’s wiring involves personnel risk due to shocks. Also it causes permanent damage to use the electrical insulation. In such cases sand is the most commonly used fire fighting material. The sand cuts the supply of oxygen to the fire.
- In most cases of fire, however, the point of conflagration is not easily accessible. The fire fighting operations will have to be done from distance only. Handy chemical fire extinguishers are, therefore, stored at convenient places and this case readily be used for directing the jet of the extinguishing fluid against the fire. In chemical fire extinguishers, no fire extinguishing chemicals are discharged but the gas generated by the chemical action is used as a propelling agent.
3.1 Preventive Measures
- Fuses of correct type and size must only be used for replacement.
- Bare fuse wires of strands of copper wire should not be used to replace blown fuses.
- All mains supply fuses should be inside their covers or cartridges and should not be exposed.
- It is necessary that all alarms type fuses should have the correct color beads fitted on them. Only fuse wire of correct rating should be used for their repairs.
- Resistance spools should not be used indiscriminately, without any regard to their capacity for heat dissipation. The heat dissipated must not raise the temperature of the resistance spool to such a degree as to cause fire.
- While considering the wattage of the resistance to be used, maximum current that may flow through it under fault condition should be taken into account and not merely the current under normal conditions of operation
- For all resistances above 2 watts dissipation ceramic Bobbin type resistance coils should be used.
- All connections should be firmly fixed and soldered wherever necessary.
- All jack strips should be properly fitted and strip fastener screws properly tightened.
- All power leads, especially those carrying heavy current must have conductors of gauge, sufficient to carry safely the maximum amount of current that is likely to pass through time.
- The leads should be of the proper lengths with just a little length spare for repairs etc.
- Even for temporary repairs, unnecessarily long lengths of wire or the wire of gauge smaller than what is needed should not be used.
- In manual exchange and auto switch room the passages round the switch boards or equipment tacks should be kept clear of combustible material like books, directories, files, bottles of oil mythelated and denatured sprit, oil, pieces of cable etc. as they are likely to assist in spreading of fire.
- Smoking in switch room, power room, equipment room cable chamber, battery room, and MDF room should be strictly prohibited.
- Where it is necessary to use blow lamps in apparatus room, ensure that asbestos blanket 3’ X 3’ and a bucket of sand is ready. The lighting of blowlamp should be carried out away from the apparatus rooms.
- Naked lights should not be used and may not even be stored in rooms.
- Avoid accumulation of dirty cotton waste and especially oily rags and waste in the power room.
- Whenever electric soldering iron is in use a red pilot lamp must be in circuit.
Precautions to be taken against spread of fire in Telecom Buildings
- Adequate arrangements for provision of fire fighting appliance should be made.
- In addition to fire extinguishers, buckets with water or with sand should be provided according to requirement and care should be taken to see that the buckets do not remain empty 1 and that they are not used as spittle box waste paper baskets.
- In large buildings, water hydrants and hoses may be provided and kept near the water mains together with proper connecting fittings and tools for the same.
- Fire alarm should be installed in the building.
- A non-exchange direct fire emergency magneto telephone should be provided in all important telecom buildings for direct communication with the fire Brigade station.
- Proper maintenance of the Fire Extinguishers should be done. For proper maintenance of fire extinguishers, following points may be noted.
They should be kept in good condition at all times and should always be kept in their appointed place.