IEC 60079-15:2017 specifies requirements for the construction, testing and marking for Group II electrical equipment with type of protection ono which includes; sealed devices onCo, hermetically sealed devices onCo, non-incendive components onCo and restricted breathing enclosures onRo 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 (Clause 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. This fifth edition cancels and replaces the fourth edition, published in 2010, and constitutes a technical revision. Refer to the Forward of the document for a complete listing of the technical changes between edition 5.0 and the previous edition of the document.