1 Overview 　　ZF10-126(L) Gas Insulated Metal-Enclosed Switchgear (hereinafter referred as GIS) is applicable for the electrical system with features of three phases AC, 50HZ, and rated voltage of 126kV. 　　The GIS meets the relative requirements of national standard - GB7674-2008 and international standard IEC60517-1990. All the components inside the GIS conform to the corresponding national standard. 2 Service and Installation Conditions 　　Installation site: Indoor/outdoor 　　Ambient temperature: -15℃~+40℃(indoor)/-35℃~+40℃(outdoor) 　　Altitude: 1000m (No limitation for special order) 　　Humidity: 　　Relative humidity at average per day (25℃): ≤95% 　　Relative humidity at average per month: ≤90% 　　Wind speed: ≤ 35m/s (wind pressure ≤700Pa) 　　Sunshine intensity:  0.1w/cm(at wind velocity of 0.5m/s) 　　Icing thickness: 10mm 　　Seismic intensity: 　　Horizontal acceleration: ≤0.4g 　　Vertical acceleration: ≤0.2g 　　Symmetrical Creepage distance:  25mm/kV (pollution class III), 31mm/kV (class IV) 　　Keep the breaker away from places with combustible, explosive, corrosive materials and violent vibrations.