Published: 2026-08-26
Severe electromagnetic interference areas in industrial sites: frequency converters, servos, high-power motors—if control signal cables are not properly shielded against interference, malfunctions and signal loss are normal. Many people only focus on whether there is a shielding layer and ignore the knowledge of grounding.
The role of the shielding layer is to divert the interference current, but **where to divert it to** is the key:
Single-ended grounding (one end connected to the earth): suitable for low-frequency interference, avoids ground loop currents
Dual-end grounding: Suitable for high-frequency interference, the shielding layer forms a low-impedance loop
Mixed grounding (one end direct, one end through a capacitor): balances high and low frequencies, commonly used in engineering
Connected incorrectly, the shielding layer instead introduces interference. For example, with encoder cables near the inverter, if both ends of the shielding layer are connected to the grounding rail in the control cabinet, and there is a potential difference between the two grounding points, the ground loop current will generate interference voltage on the shielding layer, making the signal worse.
Another aspect that is easily overlooked is **shielding continuity**: if the shielding layer is broken at intermediate joints or adapters, the anti-interference capability drops to zero. Connectors should use shielded connectors or a 360° circumferential overlap of the shielding layer, not just a single wire connection.
Selection suggestion: In interference-resistant scenarios, clearly report the type of interference source (frequency converter/motor/high-frequency equipment), signal type, and grounding method, so that the manufacturer can match the shielding structure. Shanghai Suoqi control cables and encoder cables support custom double-layer shielding and can be designed to cooperate with the on-site grounding scheme.
About Shanghai Suoqi
Shanghai Suoqi Electric Wire & Cable Co., Ltd. is a specialized cable enterprise focusing on the research and development, design, production, and sales of special flexible cables. The company's products cover a series including reel cables, flat cables, drag chain cables, encoder cables, polyurethane cables, seawater-resistant cables, seawater-resistant network cables, and high-altitude vehicle cables, which are widely used in ports machinery, mining, industrial automation, marine engineering, and other fields. For more product information or inquiries, please call 13311756197 (same number on WeChat).