| Absolute necessity |
| Criteria for decisions |
| Main tube or evaluation unit |
| The suction device |
| Rapid Detection |
| Options |
| Individual identification |
| Examples of Applications |
Detecção de
fumaça por
aspiração
Detector
de temperatura
Cabo sensor
Detector
de temperatura
Tubo sensor
Equipment Monitoring in Computer Installations and Control Cabinets
The installation of smoke suction systems for monitoring the equipment in computer installations and switchgear and control cabinets is undisputed nowadays. All that remains open are questions of fitting details. The following hints may be of help when taking decisions.
The following criteria, among others, play a role when
planning an equipment monitoring installation with aspiration smoke detection
systems:
– Details specific to an installation: Location of the air outlet
(side, top), air release speed.
– Frequency of computer relocations or reequipment.
– Subsequent measures: Activation of the gas extinguishing system,
alarming concept (e. g. switching off computers, ventilation, alarming
the fire service).
– Required detection speed.
– Individual identification of computer cabinets, etc.
In addition, the official national guidelines applicable in each case have to be taken into account.
Fastening of the ASD with a mounting
plate to the outside of a computer cabinet
Central main tube or evaluation unit on the equipment?
The Securiton ASD aspration smoke detection system can
be mounted directly on the outside of a cabinet without mechanical interference
using a mounting plate. This solution is used wherever only one to two
cabinets are to be monitored together using one ASD. In the case of larger
systems, a different concept is to be recommended: a central main tube
mounted in the hollow floor, on the ceiling or on the wall leads from
the evaluation unit to close to the cabinets. The cabinet is connected
by means of junctions and flexible suction tubes. This arrangement has
the following advantages:
– With an ASD, several cabinets can be monitored simultaneously,
thus saving costs.
– Cabinets can be shifted without problems, new ones added and existing
ones removed.
Lead in of the suction tubes through the
hollow floor with possible connections
for flexible tubes
The arrangement and the place of fitting are very much dependent on the layout of the air outlet opening and the air outflow speed. It should be noted that the air outflow must not be obstructed as far as possible so that as high a proportion as possible of air can be checked for smoke. It should further be noted that mechanical interventions for fixing the suction points are not permitted by computer manufacturers as a rule. Extensive tests have shown that in the majority of cases, a small cylindrical funnel is the right solution. By comparison, large suction funnels disturb the air through put too much and offer few technical advantages in protecting against fire.
Detail of the tube fastening and a suction
funnel
The extremely flexible Securiton suction point range can be adapted to suit every operating rquirement. As a rule, installation is made using double-sided adhesive tape without any mechanical intervention. Depending on the size of the air outlet aperture, the system operates with 2 or 4 suction points in T or H form.
Suction points with 4 apertures in H form
If required, most rapid smoke detection
Depending on the detection characteristics necessary,
another type of aspration
smoke detection system is employed.
– ASD 515 with PSU 53: an optical smoke detector; limit value alarm
in accordance with EN-54/7; connection of PSU 53 possible with highly
sensitive, 10-stage analogue evaluation in the range of 0–50% of
the EN-54/7 alarm threshold. Deployment: earliest possible smoke detection.
– ASD 515-2: two smoke detectors, mixed component placement optical
and ionisation principle; limit value alarm in accordance with EN-54/7,
with warning signal at 50% and warning alarm with actuation of the first
detector. Deployment: General equipment monitoring, triggering of extinguishing
equipment with twin-detector dependence.
TAR 54
The TAR 54 temperature monitoring device is available as an option. The
temperature at the suction points is measured by means of temperature
sensors and evaluated in the TAR 54 evaluation unit. The response threshold
of the temperature alarm can be set in 5° C steps. Wiring of the temperature
sensors is made through the suction tubes, the evaluation unit is pulled
into the suction tube in front of the aspration smoke detection system.
TAR 54 temperature monitoring
Individual identification of each cabinet
If individual identification is required, a ASD aspration smoke detection system device can be mounted on each cabinet. However, there is another solution: Using a detector box which is fitted directly at the suction points of each cabinet, individual cabinet identification can be achieved with one single smoke suction system. Up to 6 air outlet openings can here be connected to one ASD. The detectors in the detector boxes are connected to the fire detection unit centre like normal point detectors.
Further examples of applications for the ASD aspration smoke detection system
Installation monitoring in EDP systems and control
cabinets
Protection of hollow floors and hollow ceilings
Supervision of prison cells and isolation wards
in clinics
Fire detection in high-storage warehouses
Invisible fire detection for the protection of
cultural goods
Fire detection in electrical switchgear installations
Fire detection in cold-storage warehouses
Fire protection in unheated rooms, e. g. roof frameworks
Fire protection in high voltage and EMV laboratories
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