The low-voltage electrical appliances in the stainless steel distribution box are composed of fuses, communication contactors, residual current action maintainers, capacitors and meters. These low-voltage electrical appliances are designed and manufactured in accordance with GB1497 "Basic Specifications for Low-Voltage Electrical Appliances", and the corresponding rules for their normal working conditions are: the upper limit of ambient air temperature does not exceed 40 °C; the average value of ambient air temperature does not exceed 35 °C The lower limit of the ambient air temperature is not lower than -5 ° C or -25 ° C.