2251EM PHOTOELECTRIC SMOKE SENSOR

The 2251EM photoelectric smoke detector combines a state of the art sensing chamber with microprocessor control and sophisticated processing to eliminate transient noise conditions thereby giving reliable fire detection whilst minimising unwanted alarms. It is approved to a range of sensitivities, permitting the detector to be configured to match the application environment.

The 2251EM includes algorithms, which compensate for slow build up of contamination such as dust, within

the sensing chamber. Once the detector has reached its maximum compensation level, a signal can be sent to the control panel to indicate the need for maintenance.

Tested and approved to EN54-7: 2000 by LPCB

Specifications

 

Height:

45mm in B501 Base

Weight:

102g excluding base

2251TEM PHOTO–THERMAL SENSOR

The 2251TEM multi-criteria fire sensor incorporates an optical smoke-sensing chamber and thermal-sensing elements combined with microprocessor control and sophisticated processing to eliminate transient noise conditions thereby giving reliable fire detection whilst minimising unwanted alarms. It can respond either as a smoke detector, or a rate of rise heat detector or, using special algorithms combining both elements to provide improved reliability of detection.

The 2251TEM is an environmentally friendly replacement for an ionisation detector, providing rapid detection of fast, flaming fires without incurring the significant end- of-life disposal costs associated with products containing radioactive material.

The 2251TEM is approved to a number of sensitivity settings: Three Photo-Thermal and two Auto-Adjusting, which slowly adjust the detector’s sensitivity to match short term changes in its environment, thus reducing the potential for nuisance alarms. In addition, it is possible to detect an alarm from heat only, for day/night operation for example.

Similarly to the 2251EM, the 2251TEM includes algorithms, which compensate for a slow build up of contamination, such as dust, within its optical sensing chamber. Once the detector has reached its maximum compensation level, a signal can be sent to the control panel to indicate a the need for maintenance.

Tested and approved to CEA 4021, EN54-7: 2000 and EN54-5: 2000 (Class A1R) by LPCB

Specifications

 

Height:

45mm in B501 Base

Weight:

115g excluding base

Note: This document is based on the recommendations of BS5839 Part 1: 2002. It is intended only as a guide to the application of fire detection systems.

Reference must be made to relevant national and local standards.

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System Sensor BS5839 manual System Sensor Intelligent Product Range, 2251EM Photoelectric Smoke Sensor, Weight
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BS5839 specifications

System Sensor BS5839 is a standard that pertains to fire detection and alarm systems, providing guidelines for the design, installation, and maintenance of these essential safety tools. It is crucial for safeguarding lives and property, ensuring that fire detection systems are effective and reliable. The BS5839 standard, established in the UK, covers a wide range of fire alarm system types, including conventional, addressable, and wireless systems.

One of the main features of BS5839 is its comprehensive classification of fire detection systems. The standard divides systems into categories based on the level of risk and the environment in which the system will operate. This classification helps ensure that the system installed meets the specific needs of the building and its occupants. For example, Category L systems are meant for life safety, while Category P systems are designed to protect property.

The technologies underpinning BS5839 include various types of detectors, alarm devices, and control panels. Smoke detectors, heat detectors, and multi-sensor detectors are prominent among the devices specified in the standard. Smoke detectors use photoelectric or ionization principles to detect smoke and signal an alarm, while heat detectors respond to temperature changes. Multi-sensor detectors combine both smoke and heat detection technologies to provide a more reliable response to fire conditions.

Another key characteristic of BS5839 is the emphasis on regular testing and maintenance. The standard outlines procedures to ensure that systems remain operational and effective over time. This includes routine system checks, functional testing, and more in-depth inspections at regular intervals. Ensuring that systems are maintained according to BS5839 is vital for compliance with insurance requirements and for safeguarding against potential legal liabilities.

Furthermore, BS5839 highlights the importance of staff training and awareness. It emphasizes that personnel responsible for fire safety must be adequately trained in the operation and response to fire alarm systems. This ensures that in the event of a fire, occupants are prompted to take appropriate action and evacuate safely.

In summary, System Sensor BS5839 provides a crucial framework for fire detection and alarm systems. Its classification of systems, incorporation of advanced technologies, and emphasis on maintenance all contribute to enhanced safety and compliance, protecting lives and property effectively.
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