DIN EN 60079-35-1:2012-01

This part of the standard IEC 60079-35 specifies requirements for the construction, testing and marking of caplights, including caplights with a point of connection for other equipment, for use in mines susceptible to firedamp (Group I - electrical equipment for explosive gas atmospheres as defined in IEC 60079-0). It deals only with the risk of the caplight becoming a source of ignition. The requirements for performance are contained in IEC 60079-35-2. This standard supplements and modifies the general requirements of IEC 60079-0, except as indicated in Table 1. Where a requirement of this standard conflicts with a requirement of IEC 60079-0, the requirements of this standard shall take precedence. Compliance with this standard will provide an equipment protection level (EPL) of "Mb". If an equipment protection level (EPL) of "Ma" is required, the caplight will need to conform to the requirements of 4.2 of this standard, which in turn refers to IEC 60079-11. It is expected that, from time to time, caplights conforming to this standard (EPL "Mb") will operate in atmospheres where the firedamp exceeds statutory levels that require the withdrawal of people from the high firedamp atmosphere to a non-hazardous area. In designing equipment for operation in conditions other than those given above, this standard may be used as guidance; however, additional testing may be required. Where a caplight is assessed as intrinsically safe equipment, Ex "ia", conforming to IEC 60079-11, only the clauses listed in 4.2 require application. The following modifications have been made with respect to DIN EN 62013-1 (VDE 0170-14-1):2007-02: a) the inclusion of Table 1 listing the exclusion of specific clauses of IEC 60079-0; b) redrafting in the style of other IEC 60079 series standards; c) the introduction of a means to assess caplights to with EPL Ma; d) the introduction of a single clause relating to equipment construction replacing individual specific clauses for the headpiece, battery, cable and external charging contacts; e) the deletion of statements relating to surface temperature, the rewording of statements relating to creepage and clearance and the addition of statements relating to thermal protection, electronic assemblies and additional circuitry; f) specific reference to lithium cells has been made; g) the addition of statements relating to battery recharging and protection against deep discharge. The responsible committee is K 241 "Schlagwetter- und explosionsgeschützte elektrische Betriebsmittel" ("Electrical apparatus for potentially explosive atmospheres") of the DKE (German Commission for Electrical, Electronic and Information Technologies) at DIN and VDE.