IEC/SC 31D - IEC_SC_31D

This European Standard contains the specific requirements for the construction and testing of electrical apparatus with type of protection pressurization p intended for use in potentially explosive atmospheres. This European Standard supplements European Standard EN 50014, the requirements of which apply to electrical apparatus with type of protection p. This European Standard includes the requirements for the construction of the enclosure and its associated components, including if any, the inlet and outlet ducts for the protective gas, and for the safety provisions and devices necessary for the type of protection pressurization p. This European Standard specifies the requirements for pressurized enclosures with or without an internal source of release, with the exceptions given hereafter. This European Standard specifies requirement for pressurized enclosures containing an unlimited source of release of flammable gas or vapour only where the unlimited source of release is from the surface of a liquid. This European Standard does not contain requirements for pressurized rooms or analyser houses. This European Standard does not contain the requirements for pressurized enclosures where, in a containment system with limited or unlimited release there is: air with an oxygen content greater than normal, or oxygen in combination with inert gas in a proportion greater than 21%. Due to the safety factors incorporated in the type of protection the uncertainty of measurement inherent in good quality, regularly calibrated measurement equipment is considered to have no significant detrimental effect and need not be taken into account when making the measurements necessary to verify compliance of the apparatus with the requirements of this standard

Superseded by EN 50016:1995