WSD-VZF(R) -27/630-25 removable vacuum load switch + fuse combination electrical appliances (hereinafter referred to as combination electrical appliances) is a new generation of three-phase AC 50Hz, rated voltage 27kV indoor switchgear developed according to unique design concept and market demand. It is widely used in indoor armoured air insulated switchgear. It meets the requirements of GB3804-2004, GB16926-1997 and other standards. Under normal operating conditions, as long as the technical parameters of the vacuum switch are within the range, it can ensure the safe and reliable operation of the corresponding voltage level of the power grid. Environmental Conditions for Use The ambient temperature should not be higher than + 40, not lower than 10Â (storage and transportation allowed at 30) Elevation does not exceed 1500m. Relative humidity: the daily average is not more than 95%, the monthly average is not more than 90%, the daily average of saturated vapor pressure is not more than 2.2 x 10-3 Mpa, and the monthly average is not more than 1.8 x 10-3 Mpa. Earthquake intensity does not exceed 8 degrees. No fire, explosion danger, serious pollution, chemical corrosion and violent vibration.