Will the waterproof connector on the edge box affect the grounding continuity of the interface?

Edge computing boxes used in outdoor applications are often equipped with waterproof connectors. These connectors are mostly made of plastic. If used directly for shielded cables, they will sever the electrical continuity between the shielding layer and the chassis, leading to high-frequency grounding failure. The correct approach is twofold:

1. Use a metal waterproof connector with a threaded connection to the chassis, ensuring the shielding layer is pressed 360° into the connector. The tapered sleeve connector surface is treated with conductive oxidation, and the contact resistance is <5mΩ.

2. If a plastic connector is used, the shielding layer needs to be connected to signal ground on the PCB side via a 1nF/2kV Y capacitor and connected in series with a common-mode magnetic ring CMZ7060A-701T to suppress radiated emissions.

Actual measurements showed that after switching an edge computing box to a metal waterproof connector, the radiated emissions from 30-100MHz decreased by 12dB. Therefore, the selection of waterproof connectors must take grounding continuity into account.