BS 54-23:2010 pdf download – Fire detection and fire alarm systems Part 23: Fire alarm devices — Visual alarm devices
4.2.3 Flammability of materials The VAD shall be constructed of material(s) capable of withstanding the tests specified in Clause 5. In addition, the material(s) of plastic enclosures shall meet the following flammability requirements:
a) EN 60695-11-10:1999 as amended by EN 60695-11-10:1999/A1:2003 Class V-2 or HB75 for devices operating from a voltage source less than or equal to 30 V RMS or 42,4 V DC and consuming less than 15 W of power;
b) EN 60695-11-20:1999 as amended by EN 60695-11-20:1999/A1:2003 Class 5VB for devices operating from a voltage source greater than 30 V RMS or 42,4 V DC and consuming more than 15 W of power. NOTE Annex D gives information on the test requirements and classification given in the IEC standards and equivalent flammability ratings in UL 94.
4.2.4 Enclosure protection The degree of protection provided by the enclosure of VADs shall meet the following requirements:
a) for Type A VAD: Code IP21C of EN 60529:1991;
b) for Type B VAD: Code IP33C of EN 60529:1991.
4.2.5 Access Means shall be provided to limit access for removal of parts or the whole device, e.g. special tool, codes, hidden screws, seals, etc.
4.2.6 Manufacturer’s adjustments It shall not be possible to change the manufacturer’s settings except by special means (e.g. the use of a special code or tool) or by breaking or removing a seal.
4.2.7 On site adjustments of behaviour If there is provision for on-site adjustment of the behaviour of the VAD:
a) for each setting at which compliance with this standard is claimed, the VAD shall comply with the requirements of this standard and access to the adjustment means shall only be possible by the use of a code or special tool or by removing the VAD from its base or mounting; and
b) any setting(s) at which compliance with this European Standard is not claimed, shall only be accessible by the use of a code or special tool and it shall be clearly marked on the VAD or in the associated data that when these setting(s) are used, the VAD does not comply with the standard. NOTE These adjustments may be carried out, for example, at the VAD or at the control and indicating equipment.
4.2.8 Requirements for software controlled devices General For VADs which rely on software control in order to fulfil the requirements of this European Standard, the requirements of, and shall be met. Software documentation Documentation which gives an overview of the software design shall be submitted. This documentation shall be in sufficient detail for the design to be inspected for compliance with this European Standard and shall include at least the following:
a) a functional description of the main program flow (e.g. as a flow diagram or structogram) including:
1) a brief description of the modules and the functions that they perform;
2) the way in which the modules interact;
3) the overall hierarchy of the program;
4) the way in which the software interacts with the hardware of the VAD;
5) the way in which the modules are called, including any interrupt processing;
b) a description of which areas of memory are used for the various purposes (e.g. the program, site specific data and running data);
c) a designation, by which the software and its version can be uniquely identified. Detailed design documentation, which only needs to be provided if required for assessment purposes, shall comprise at least the following:
a) an overview of the whole system configuration, including all software and hardware components;
b) a description of each module of the program, containing at least:
1) the name of the module;
2) a description of the tasks performed;
3) a description of the interfaces, including the type of data transfer, the valid data range and the checking for valid data;BS 54-23 pdf download.