Bosch Addressable Smoke & Heat Detector

Features:

• Highly reliable and accurate thanks to Intelligent Signal Processing (ISP)

• Earliest detection of lightest smoke with dual optical Versions (Dual-Ray technology)

• Monitors environment for electromagnetic influence For fast root-cause analysis

• Automatic and manual addressing

AVENAR detector 4000 is a new range of automatic fire detectors featuring a superb accuracy and swiftness in detection. The versions with two optical sensors (dual‑optical) are able to detect the lightest smoke. The range includes versions with rotaries, manually and automatically addressable, and versions without rotaries for automatic address setting.

Sensor technology and signal processing The individual sensors can be configured manually, or

timer-based via the LSN network. All sensor signals are analyzed continuously by the internal evaluation electronics (ISP – Intelligent Signal Processing) and are linked with each other via an inbuilt microprocessor. The link between the sensors means that the combined detectors can also be used

where light smoke, steam or dust must be expected during the course of normal operation. Only if the signal combination corresponds to the characteristics of the application site, selected during the programming, the alarm is triggered automatically.

This results in less false alarms. In addition, the time of the sensor signals on fire and fault detection is analysed, which leads to high

detection reliability for each individual sensor. In the case of the optical and chemical sensor, the response threshold (drift compensation) is actively adjusted. Manual or time-controlled switch-off of individual sensors is required for adjustment to extreme interference factors.

Optical sensor (smoke sensor)

The optical sensor uses the scattered-light method.

An LED transmits light to the measuring chamber,

where it is absorbed by the labyrinth structure. In the

event of a fire, smoke enters the measuring chamber

and the smoke particles scatter the light from the LED.

The amount of light hitting the photo diode is

converted into a proportional electrical signal.

The dual-optical versions use two optical sensors with

different wavelengths. The Dual-Ray technology works

with an infrared and a blue LED so that lightest smoke

is detected fast and reliably (TF1 and TF9 detection).

Thermal sensor (temperature sensor)

A thermistor in a resistance network is used as a

thermal sensor from which an analog-digital converter

measures the temperature-dependent voltage at

regular intervals.

Depending on the specified detector class, the

temperature sensor triggers the alarm status when the

maximum temperature of 54 °C or 69 °C is exceeded

(thermal maximum), or if the temperature rises by a

defined amount within a specified time (thermal

differential).

Further characteristics

• A red flashing LED visible 360° indicates the alarm.

• Connection to a remote indicator is possible.

• The strain relief for cables in false ceilings prevents

the cables from being unplugged accidentally from

the terminals after installation. The terminals for

cable cross-sections up to 2.5 mm2 are very easily

accessible.

• The detectors have a dust-repellent labyrinth and cap

construction. The chamber maid plug (an opening

with closing plug) on the bottom is used to clean the

optical chamber with compressed air (not required

for the heat detector).

• The detector bases no longer have to be directed due

to the centralized position of the individual display.

They also have a mechanical removal lock (can be

activated and deactivated).

Improved LSN features

AVENAR detector 4000 offers all the features of the

improved LSN technology:

• Flexible network structures, including T‑tapping

without additional elements (no T-tapping feasible for

versions without rotaries)

• Up to 254 LSN improved elements per loop or stub

line

• Automatic or manual detector addressing, with or

without auto-detection

• Power supply for connected elements via LSN bus

• Unshielded fire detection cable can be used

• Cable length up to 3000 m (with LSN 1500 A)

• Backwards compatibility to existing LSN systems and

central units

• Monitoring of environmental electromagnetic impact

for fast root-cause analysis (EMC values are displayed

on the panel)

In addition, the range offers all the established

benefits of LSN technology. The panel programming

software can be used to change the detection

characteristics of the respective room utilization. Each

configured detector can provide the following data:

• Serial number

• Contamination level of the optical section

• Operating hours

• Current analog values

– Optical system values: current measured value of the scattered light sensor; the measuring range is linear and shows different degrees of pollution, from slight to heavy.

– Contamination: the contamination value shows how much the current contamination value has increased relative to the original condition.

– CO value: display of the currently measured value (max. 550).

The sensor is self-monitoring. The following errors are indicated on the fire panel:

• Fault indication in the event of the failure of the detector electronics

• Continuous display of contamination level during Service

• Fault indication if heavy contamination is detected (instead of triggering a false alarm) In the event of wire interruption or short-circuit,

integrated isolators maintain the functional security of the LSN loop. In the event of an alarm, individual detector identification is transmitted to the fire panel.