AS NZS 60079.15:2020 pdf free.Explosive atmospheres Part 15: Equipment protection by type of protection “n” (IEC 60079-15:2017 (ED.5.0) MOD).
4 General
4.1 Equipment grouping and temperature classification
Equipment grouping and temperature classification shall be in accordance with the equipment grouping and temperature classification clauses of IEC 60079-0.
4.2 Potential ignition sources
In normal operation and in certain regular expected occurrences specified by this standard, the equipment shall not:
a) produce an operational arc or spark unless that arc or spark is prevented from causing ignition of a surrounding explosive atmosphere by one of the methods described in Clauses 7 to 10;
b) develop a maximum surface temperature in excess of the maximum value appropriate to the temperature class of the equipment, unless the temperature of the surface or hot spot is prevented from causing ignition of a surrounding explosive atmosphere by one of the methods described in Clauses 7 to 10 as appropriate, or is otherwise shown to be safe as specified in 5.
4.3 Equipment requirements
Equipment or components which in normal operation produce arcs, sparks or hot surfaces which otherwise would be capable of igniting a surrounding atmosphere shall be protected against causing ignition by one or more of the following methods, all of which provide Equipment Protection Level Gc:
a) non-incendive component (see Clause 7);
b) hermetically sealed device (see Clause 8);
C) sealed device (see Clause 9);
d) restricted-breathing enclosure (see Clause 10).
5 Maximum surface temperatures
The maximum surface temperature shall be determined in accordance with the determination of maximum temperature classification requirements of IEC 60079-0. The surface to be considered shall be the external surface of the equipment including the surface of internal parts of non-incendive components to which the explosive gas atmosphere has access.
NOTE This is often the outside surface of type of protection TMnC” components located within level of protection “ec equipment.
6 Requirements for electrical equipment
6.1 General
Electrical equipment with type of protection “n” shall comply with the requirements of this standard and the applicable parts of IEC 60079-0 for the method(s) of protection used. AS NZS 60079.15 pdf download.