Mitigating Long-Cable Interference: ODES EMC-Enhanced Auxiliary Relay Solutions

TonyZhang
Aug 31
2 min read

Problem Statement

In substations, switchgear, and industrial automation systems, long signal cables are often necessary to connect protection and control devices. However, extended cable runs introduce a critical challenge: electromagnetic interference (EMI). Acting as unintended antennas, these cables can couple with external electric fields, magnetic fields, and transient disturbances. The result is signal distortion, nuisance operation, or unintended relay pickup/reset, which directly compromises system security and reliability.

Why Conventional Methods Are Insufficient？

Shielded cables, grounding optimization, and cable routing practices can reduce—but not fully eliminate—EMI in long control circuits. Under high-frequency or transient conditions, these measures often fail to ensure stable signal transmission and may still lead to spurious operations.

Solution Approach: ODES Anti-Interference Auxiliary Relay

The EMC-hardened auxiliary relay is engineered to insert a controlled isolation and signal restoration point in long-cable paths. Through optimized electromagnetic compatibility (EMC) design and galvanic isolation, the relay suppresses conducted and radiated interference while preserving the integrity of protection and control signals.

Core Features & Capabilities

Superior EMC Immunity: Designed in accordance with IEC 60255 and equivalent ANSI/IEEE criteria; tested for high immunity against electrostatic discharge, radiated RF, fast transients, and surge disturbances.
Reliability Enhancement: Prevents false operations and control malfunctions caused by EMI, ensuring continuity of service and accurate relay coordination.
Versatile Application: Applicable in substation automation, renewable energy installations, switchgear, and mixed AC/DC control environments.
Lifecycle Cost Efficiency: Reduces corrective maintenance, downtime losses, and long-term operational risk associated with interference-induced failures.

Engineering Value

Unlike passive shielding measures, the ODES EMC-hardened auxiliary relay applies an “isolate–reshape–transmit” principle, establishing an active barrier in the signal path. This not only suppresses EMI sources but also strengthens system maintainability and operational stability over the asset lifecycle.

Standards, Validation & Testing

ODES Anti-Interference Auxiliary Relay Series are type-tested for EMC performance, dielectric withstand, temperature endurance, and mechanical durability in accordance with IEC 60255 requirements. Compliance ensures interoperability and reliability within international engineering practice.

Application Domains

Substation and switchgear panels: Eliminates long-cable induced interference in control circuits.
Renewable energy stations: Ensures reliable command transmission in high-EMI outdoor environments.
Industrial control systems: Provides secure isolation for weak-signal circuits in proximity to strong-current equipment.

Conclusion

Wherever long control cables expose systems to electromagnetic interference, ODES EMC-hardened auxiliary relays provide a standards-aligned, field-proven mitigation path. By ensuring distortion-free signal transmission, they strengthen operational reliability and enhance system resilience.