IEC 62271-214:2019 specifies requirements for internal arc classification of metal-enclosed pole-mounted switchgear installations used for alternating current with rated voltages above 1 kV and up to and including 52 kV with service frequencies up to and including 60 Hz. This document is applicable to three-phase, two-phase and single phase equipment. Enclosures may include fixed and removable components and may be filled with fluid (liquid or gas) to provide insulation.