Plant engineers upgrading older production lines with modern networking face a constraint that new facilities rarely encounter: limited cable pathways. In many existing plants, new Ethernet lines must run close to heavy motor power cables, variable frequency drives, and other equipment that was never designed with data transmission in mind. This proximity creates electromagnetic interference (EMI), which can degrade signal integrity and contribute to communication errors or packet loss on industrial networks.

What EMI Means for Brownfield Projects

EMI is unwanted electromagnetic energy that produces noise or signal distortion, disrupting normal device operation. Industrial machinery, power lines, and wireless signals are common sources. A related concept, electromagnetic susceptibility (EMS), describes how resistant a device or cable is to these disturbances. EMI and EMS both fall under electromagnetic compatibility (EMC) — the discipline of keeping devices from interfering with, or being disrupted by, their surroundings.
In a retrofit, where communication and power cables may be forced into nearby trays, panels, or constrained routing paths, EMC stops being an abstract concept and becomes a practical wiring decision.

Shielded M12 Ethernet Cordsets

One way to manage this risk is with shielded M12 D-coded Ethernet connectors. These use a keyed M12 connector on the field side and terminate in an RJ45 connection for switch or controller-side equipment. Shielded variants are available with the cable shield terminated at both connector ends, or at the RJ45 end only, depending on the grounding scheme required. Cable jackets are offered in PVC, PUR, and TPE, with housings in nickel-plated brass.
The M12 mating interface carries an IP69 rating for protection against dust and high-pressure washdown. The RJ45 interface itself is rated IP20, reflecting its typical use inside an enclosure rather than direct field exposure.

EMI Shielding Cable Glands

Where a cable shield needs to be grounded at a panel or enclosure wall, EMI shielding cable glands provide a mechanical connection between the cable shield and the enclosure body. These nickel-plated brass glands carry an IP68 rating and are available in PG and metric thread sizes, allowing them to be matched to existing panel cutouts during a retrofit rather than requiring new enclosure modifications.

Planning Considerations

A reliable brownfield Ethernet upgrade starts with thoughtful cable routing. Whenever possible, communication and power cabling should be physically separated to minimize EMI exposure. When existing infrastructure limits routing options, shielded M12 Ethernet cordsets and properly grounded EMI shielding cable glands can provide an added layer of protection. When incorporated into a well-designed grounding and bonding strategy, these components help support stable network communication and long-term reliability in demanding industrial environments.

About Mencom Corporation

Mencom Corporation is a manufacturer of industrial power, control, signal, and networking connector solutions, with facilities in the U.S. and Europe. Mencom’s product range includes circular and rectangular industrial connectors, panel interface connectors, cable glands, and industrial networking components, including the M12 D-coded Ethernet cordsets and EMI shielding cable glands described above. Mencom also serves as the U.S. Master Distributor for ILME heavy-duty rectangular connectors.

Please visit www.mencom.com for more details.