IEC 62271-207 applies to: gas-insulated switchgear (GIS) assemblies for alternating current of rated voltages above 52 kV complying with IEC 62271-203; for direct current of rated voltages including and above 100 kV for indoor and outdoor installations, including their supporting structures; metal-enclosed switchgear and controlgear assemblies for rated voltages above 1 kV and up to and including 52 kV complying with IEC 62271-200 for metal-enclosed and IEC 62271- 201 for solid-insulation enclosed, ground or floor mounted, intended to be used under seismic conditions. The seismic qualification of the switchgear assemblies takes into account testing of typical switchgear assemblies combined with methods of analysis. Mutual interaction between directly mounted auxiliary and control equipment and switchgear assemblies is considered. Seismic qualification philosophy includes selection of seismic qualification level (Clause 4), methodologies for qualification by testing (Clause 5) and by combined testing and analysis (Clause 6), acceptance criteria (Clause 7) and seismic qualification documentation (Clause 8). The seismic qualification of switchgear assemblies by the manufacturer is only performed upon request of the user.