This part of IEC 60079 specifies requirements for the construction, testing and marking for Group II electrical equipment with type of protection “n?? which includes; sealed devices “nC??, hermetically sealed devices “nC??, non-incendive components “nC?? and restricted breathing enclosures “nR?? intended for use in explosive gas atmospheres. This part of IEC 60079 applies to electrical equipment where the rated input voltage does not exceed 15 kV r.m.s. AC or DC including where the internal working voltages of the Ex product exceeds 15 kV, for example starters for HID luminaires.
This part of IEC 60079 supplements and modifies the general requirements of IEC 60079-0, except as indicated in Table 1. Where a requirement of this part of IEC 60079 conflicts with a requirement of IEC 60079-0, the requirement of this part of IEC 60079 takes precedence.