Heavy-duty Connector Devices Of Overvoltage Category

111 Equipment belonging to overvoltage category Ill:

222 Equipment belonging to overvoltage category Ill is 333 equipment installed in the power distribution device, and 444 equipment whose use safety {working reliability} and 555 applicability must meet special requirements.

Note: This type of 666 equipment includes switching devices installed in the power distribution device and industrial 777 equipment permanently connected to the power distribution device.