Equipment Markings Maximum Loading of IS Circuit

Because of the finite resistance of the safety barrier, there will be a limit to the current drain which can be tolerated before the voltage on the circuit falls outside the specified limits for the IS detector. The standing current for the detectors can be calculated by the sum of the individual selected detector currents as given in the detector data sheet. This may limit the maximum number of detectors per barrier to two or three.

ATEX

(EU Directive 94/9/EC) CE Marking Group II

Installation

It is important that the IS detectors are installed in such a way that all terminals and connections are protected to at least IP20 with the detector cover fitted. The earth bonding terminals are provided for convenience where continuity of a cable sheath or similar is required.

II 1 G

EU Explosive A tmosphere Symbol

Service & Repairs

Equipment Type of Explosive Atmosphere Definition Servicing of IS flame detectors may be carried out only by a BASEEFA or equivalent authorised body. In practical terms this means that IS flame detector may be serviced only at the manufactures factory. Servicing of the fire protection system should be carried out as recommended by the local regulation in force.
Group II Category G
gas vapour mist Zone 1 - very high level of protection
in which explosive atmosphere mixtures of air gases, vapours or mist are present continuously, for long periods 2 - high level of protection 1
in which explosive atmosphere mixture of air and gases, vapours or mist are likely to occur 3 - normal level of protection 2
in which explosive atmosphere mixtures of air and gases, vapours or mist are unlikely to occur and if it occurs it will exist only for a short period These Flame Detectors are suitable for all the above equipment categories. Note: The detectors are not certified for explosive dust atmospheres. Table 1 Equipment Categories and Type of Explosive Atmosphere (Group II ) 10 3