The overvoltage of industrial heavy-duty electrical connectors is classified based on the voltage of the power grid and the installation location of the equipment. It describes the ability of the equipment to withstand the maximum overvoltage when a power supply system malfunctions (such as lightning strikes). According to the standard regulations, overvoltage can be divided into four categories (the following classifications comply with IEC 60664-1).

1、 Equipment belonging to overvoltage category I:
Equipment with overvoltage category l is connected to a circuit with measures to limit transient overvoltage to a relatively low level.
Note: For example, electronic circuits with overvoltage protection.

2、 Equipment belonging to overvoltage category II:
Equipment with overvoltage category II is an energy consuming device powered by a power distribution device.
Note: This type of equipment includes appliances, portable tools, and other household and similar loads.

3、 Equipment belonging to overvoltage category Ill:
Ill devices of overvoltage type are devices installed in power distribution devices, and the safety, reliability, and applicability of the equipment must meet special requirements.
Note: This type of equipment includes switchgear installed in the distribution device and industrial equipment permanently connected to the distribution device. Aerospace industrial connectors belong to this overvoltage category.

4、 Equipment belonging to overvoltage category IV:
Equipment with overvoltage category IV is used at the power supply end of the power distribution device.
Note: This type of equipment includes devices such as electricity meters and primary overcurrent protection.