HD / HS series open knife switch and knife switch

1. the ambient air temperature is not higher than +40 ℃, and not less than -5 ℃
2. the elevation of the installation site shall not exceed 2000m
3. humidity: when the maximum temperature is +40 ℃, the relative humidity of the air shall not exceed 50%, and higher relative humidity can be allowed at a lower temperature, for example, 90% at 20 ℃
4. the pollution level of the surrounding environment is grade 3
5. the switch shall be installed in places without significant shaking, shock vibration and no monthly snow attack, and the installation site shall be free of explosive dangerous medium, and there shall be no gas and dust in the medium that is sufficient to corrode metal and damage insulation.