The products is mainly applicable to a power system of AC 50Hz(or 60Hz), rated working voltage up to 230V , and in a line of application class AC-7a with rated working voltage up to 230V and rated working current up to 20A.It is used to remotely close or/and switch off the line. The product is in conformity with the standards: GB 17885 IEC 1095 Type and meaning HCH8-20 │ └Rated current (AC-7a,230V) └───H: Factory code C: AC contactor H: Household 8: Design sequence No Working condition Environmental temperature is -5℃+45℃. The average temperature in 24 hours shall not exceed +35℃ The altitude of the installation place shall not exceed 2000m. The relative humidity shall not exceed 50% when the environmental temperature is +40℃.The relative humidity may be higher at the lower temperature condition. The maximum month-average relative humidity is 90% in the most humid month with a minimum temperature +25℃ /month. The factor that dew may occur on the product surface due to temperature change shall be taken into consideration. Pollution grade:Ⅱ Installation:Ⅱ Installation mode: installed with top cap section shaped TH35-7.5 installation guide rail. The product shall be installed and operated at a place without obvious shake,impact and vibration.