How much do you know about the safe operation of the maintenance switch for electric vehicles?

How much do you know about the safe operation of the maintenance switch for electric vehicles?

(I) Types and Functions of Maintenance Switches

In pure electric and hybrid vehicles, the maintenance switch (also known as a service connector or maintenance plug) is an electrical connector between two groups of batteries in the high-voltage battery pack. When the connector is removed, the connection of the battery circuit is cut off. The residual voltage in the high-voltage system dissipates, and at this time, the high-voltage system is not energized. Typically, when it is necessary to use metal disassembly tools that could cause deformation of components or tools with sharp edges to operate on or near high-voltage components, the maintenance switch should be disconnected.

(II) Safe Operation of Maintenance Switch

The standard operation of the maintenance switch is as follows:

(1) The operation of the emergency maintenance switch should be carried out by professionals, and at least the operators should have received relevant training.

(2) During operation, operators must wear necessary protective equipment, such as insulating gloves, insulating rubber shoes (their voltage level must be higher than the highest voltage of the battery pack), etc. Before use, they need to check whether they are intact and undamaged to ensure safety.

(3) Disconnect the ignition switch and move the key out of the detection range of the smart key system. Disconnect the negative terminal of the low-voltage battery and after pulling out the handle of the maintenance switch, it must be properly stored until the maintenance is completed to avoid misoperation.

(4) After disassembling the maintenance switch, you must wait at least 10 minutes before proceeding with maintenance operations to ensure that the residual electricity in the high-voltage lines has been released. If conditions permit, it is recommended to wait for 30 minutes. After disconnecting the maintenance switch, a professional voltmeter must be used to check whether the high-voltage system has indeed been successfully de-energized.