Ground wire

Put it this way: in fact, the enclosure needs to be grounded. If both the chassis and the door are connected to the grounding strip respectively, then no connection wire is needed between them~

I took another look at your question – does it mean that there is another protective box surrounding the explosion-proof box? Is it necessary?

Is it possible that, after the explosion-proof distribution box arrived at the site, it was found to have an insufficient protection level or corrosion resistance, so a cover that provides the necessary protective functions was installed around it.

An additional box is installed outside the explosion-proof box; its main function is to protect it from rain and sunlight, thereby extending its service life.

Ahah, I’m here to complain about this sea friend! The suspicion on the 5th floor is correct; such explosion-proof boxes, equipped with additional protective covers, serve mainly to enhance their water resistance, so that the protection rating of these boxes can reach IP55 or even IP56 or higher. The number following IP indicates the level of protection against water spray: 5 denotes protection against light water spray, while 6 denotes protection against intense water spray. This is particularly useful in petrochemical facilities, as leaks from pipelines and valves located near the explosion-proof boxes could cause water to spray onto the enclosure of the electrical distribution box. Another example is the situation where explosion-proof motors come out of the factory with additional protective covers around their wiring boxes. Regarding the protective cover, it is not necessary to add a grounding wire; however, it is essential to ensure that the enclosure of the explosion-proof box has a proper and compliant separate grounding connection.

If there are no electrical components such as indicator lights or buttons on the enclosure, it is not necessary to use jumper wires