Explain Detector type? Working of it?
Regulation regarding detector?
location of it
HEAT DETECTOR
-Location-Mainly in purifier room, near boiler platform, around M/E, A/E, incinerator etc
-Position:located on the overhead shall be minimum distance of 0.5 m away from bulkhead, except in corridor, lockers and stairways.
-Operate: operate before the temp exceeds 780 c but not until temp rise 540 c when the temp rise the those limit at a rate less than 1degree c per minute.
-Regulation required:
Max floor area per detector: 37m2
Max distance a part between centre: 9 m
Max distance away from bulkhead: 4.5 m
-Power supply: from MSB, ESB and TRANSITIONAL BATTERY.
TYPES OF HEAT DETECTOR
(1) Bimetal type: in this type there will be a bimetal strip, alarm and power supply connection are there in picture. In normal condition strip will not be bend but in case of fire occurs the strip will start
bend and it will touch the point and circuit will close , so current will flow through it and it will rise the alarm. It will take some time to come in natural position becoz of the property of bimetal.
Working range is from 55c to 160c .
(2) Fusible link type: the principle is the same once it will close the circuit it will rise the alarm. In this type there is fusible link connection together, when fire occurs it will disconnect and one of the connection will touch the plate and the circuit will close and alarm will sound.
Working range is from 55 c to 180 c.
(3) Rate of rise temp pneumatic type: in this type inside the casing of detector atmospheric air is there,when fire occurs the air will get expand due to heat and the upper part of detector have diaphragm
will get expand also and it will touch the plate and circuit will close and rise the alarm.
Working range is from 57 c to 82 c.
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SMOKE DETECTOR
location-w/h port and stbd, each deck -3 ,a/c room ,galley stairway,ECR, electrical workshop, purifier room ,comb boiler ,incinerator ,generator ,purifier.
Position:located on the overhead shall be minimum distance of 0.5 m away from bulkhead, except in corridor, lockers and stairways.
Operate:operate before smoke density exceed 12.5% obscuration per minute, but not until 2%.
Regulation required:
Max floor area per detector: 74
Max distance a part between centre: 11 m
Max distance away from bulkhead: 5.5 m
Power supply: from MSB, ESB and TRANSITIONAL BATTERY.
TYPES OF SMOKE DETECTOR
(1) Ionization type: in this type detector have positive and negative charge plate in container. A positive ions attracted to negative plate and vice versa. The movement of ions between the plates reduce
resistance of the air , so small current flow in the circuit. The small current is amplified so it can be readily monitored. In fire, smoke particle entering in chamber become attached and reduction of
ions flow will increase resistance and current falls down. Amplifier senses and monitored when i will below value it will give alarm.
(2) Light obscuration type: it work on photo electric cell principle, in normal condition light source will focus on P.E.C but when fire occurs and smoke will enter in container the reduction of light source on to the P.E.C will rise the alarm.
(3) Light scatter type: it work on the opposite to obstruction type, when light source will focus on the P.E.C it will give alarm.
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Regulation regarding detector?
location of it
HEAT DETECTOR
-Location-Mainly in purifier room, near boiler platform, around M/E, A/E, incinerator etc
-Position:located on the overhead shall be minimum distance of 0.5 m away from bulkhead, except in corridor, lockers and stairways.
-Operate: operate before the temp exceeds 780 c but not until temp rise 540 c when the temp rise the those limit at a rate less than 1degree c per minute.
-Regulation required:
Max floor area per detector: 37m2
Max distance a part between centre: 9 m
Max distance away from bulkhead: 4.5 m
-Power supply: from MSB, ESB and TRANSITIONAL BATTERY.
TYPES OF HEAT DETECTOR
(1) Bimetal type: in this type there will be a bimetal strip, alarm and power supply connection are there in picture. In normal condition strip will not be bend but in case of fire occurs the strip will start
bend and it will touch the point and circuit will close , so current will flow through it and it will rise the alarm. It will take some time to come in natural position becoz of the property of bimetal.
Working range is from 55c to 160c .
(2) Fusible link type: the principle is the same once it will close the circuit it will rise the alarm. In this type there is fusible link connection together, when fire occurs it will disconnect and one of the connection will touch the plate and the circuit will close and alarm will sound.
Working range is from 55 c to 180 c.
(3) Rate of rise temp pneumatic type: in this type inside the casing of detector atmospheric air is there,when fire occurs the air will get expand due to heat and the upper part of detector have diaphragm
will get expand also and it will touch the plate and circuit will close and rise the alarm.
Working range is from 57 c to 82 c.
------------------------------------------------------------------------------------------------------------------------
SMOKE DETECTOR
location-w/h port and stbd, each deck -3 ,a/c room ,galley stairway,ECR, electrical workshop, purifier room ,comb boiler ,incinerator ,generator ,purifier.
Position:located on the overhead shall be minimum distance of 0.5 m away from bulkhead, except in corridor, lockers and stairways.
Operate:operate before smoke density exceed 12.5% obscuration per minute, but not until 2%.
Regulation required:
Max floor area per detector: 74
Max distance a part between centre: 11 m
Max distance away from bulkhead: 5.5 m
Power supply: from MSB, ESB and TRANSITIONAL BATTERY.
TYPES OF SMOKE DETECTOR
(1) Ionization type: in this type detector have positive and negative charge plate in container. A positive ions attracted to negative plate and vice versa. The movement of ions between the plates reduce
resistance of the air , so small current flow in the circuit. The small current is amplified so it can be readily monitored. In fire, smoke particle entering in chamber become attached and reduction of
ions flow will increase resistance and current falls down. Amplifier senses and monitored when i will below value it will give alarm.
(2) Light obscuration type: it work on photo electric cell principle, in normal condition light source will focus on P.E.C but when fire occurs and smoke will enter in container the reduction of light source on to the P.E.C will rise the alarm.
(3) Light scatter type: it work on the opposite to obstruction type, when light source will focus on the P.E.C it will give alarm.
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