H1-11/87-74
October 1990
by
Volker Schroeder
|
monitoring system |
fire detection installation |
|
sensors |
ionization and optical smoke detectors |
|
extinguishing system |
stationary halon extinguishing system |
|
release |
automatic or manual |
|
extinguisher supply |
stationary bottle installation |
|
extinguishing medium |
halon 1301 (CBrF3) |
|
function display |
room
301: LCD-display and printer |
|
alarm |
acoustical and optical in the trailer connected through to the technical emergency service (Technischer Notdienst) |
The fire extinguishing system of the H1-electronic trailer consists of a computer controlled fire alarm system with extinguisher steering at a halon extinguishing system.
The fire extinguishing system has been manufactured completely redundant: 2-alarm dependence, master-/slave-fire alarm central units, akku-supply. The alarm system is installed in the H1 controlroom (room 301, directly opposite the front door). Its function is indicated by a LCD-display and a paper printer. The system is connected to the DESY-fire alarm central unit at the technical emergency service (build. 35) (Technischer Notdienst).
The extinguishing system has got an individual halon supply for each extinguishing area (see below) in steel bottles. The release takes place via magnetic valves which are fixed at the bottles. The halon is conducted through a pipe-system to the objects on fire (extinguishing areas).
The functioning of the system is indicated optically on a layout board which is situated at the left side of the front door of the electronic trailer. The location and the identification number (line/No.) of each detector in the electronic trailer are marked out on this layout board by light diodes. The blinking of the diodes signals failure - steady burning alarm.
The inside of the electronic trailer is divided into 11 extinguishing areas:
|
extinguishing area 1-9 |
each row of electronic racks on the ground floor or the upper floor. |
|
extinguishing area 10 |
cable-floor, -ceiling and the room of the ground floor, as well as the cable-floor of the upper floor. |
|
extinguishing area 11 |
room and cable-ceiling of the upper floor. |
Lines of smoke detectors are allocated to each extinguishing area. Halon is released into the areas where smoke has been detected.
If halon is released in the areas 10 and 11 (rooms!), its concentration will amount to 6%. At this level a prewarning is not necessary, and the evacuation time (the time in which people have to leave the trailer) amounts to 60 sec. A halon concentration of 12% is foreseen for the flooding of the electronic racks.
While flooding a room the rack-rows therein are flooded too.
Each reaction of at least one smoke detector causes an alarm:
Acoustically (horn) and optically (flashlight and lighted sign) on the related level of the electronic trailer as well as an alarm at the technical emergency service.
The reactions of at least two neighboring smoke detectors release the halon flooding of the respective area after a delay of about 30 sec. The flooding is indicated by lighted yellow sign 'Halon released'. The room concerned must be left immediately.
A halon release can be initiated manually too. For this case push button alarms are foreseen for the nine rack rows, which are located in front of the rack rows on the wall of the longitudinal passage. The push button alarms for the rooms are located outside next to the doors.
The switching off of detector lines (e.g. to avoid false alarms during smoke producing work) has to be carried out by the technical emergency service (tel. 5555), the same applies to the quitting of impending alarms.
If in case of false alarm the halon release is to be be avoided, the push-button "HALONSTOP" on the layout-board has to be pressed until (!) either the lines which give the false alarm are switched off or the halon bottles of the respective areas are mechanically bolted (insert locking pin or remove release socket).