The discipline of cable shield termination (from Latin terminare, meaning to bound or set limits) describes the method by which the conductive screen of a cable connects to a structure to control electromagnetic interference.
The practice of shielding (from Old English scield, meaning protective covering) ensures that electromagnetic fields do not penetrate or radiate from conductors.
The principle of bonding (from Old English bindan, meaning to tie) secures low impedance connection between a shield and a conductive chassis. β‘
The arrangement of termination in both ends of a shield controls radiofrequency currents above a few kilohertz.
The method of using a Parallel Earth Conductor (a conductive path routed close to the cable and connected to earth at both ends) complements shield bonding and reduces ground loop currents.
The application of a feedthrough filter (a component that provides low impedance to ground at the point of entry of a conductor) reinforces shielding effectiveness. π§
TECHNICAL EXPOSITION
β The work appears in EMC Journal Issue 82 May 2009 and establishes that a shield termination at 360Β° in both ends maximizes electromagnetic compatibility.
β The discussion affirms that ground loops are problematic only at low frequency hum of the mains supply and not at higher frequencies.
β The text indicates that termination at one end, both ends, or none yields similar shield currents once cable length is comparable to wavelength. π‘
β The explanation recommends hybrid capacitive termination, using annular capacitors or parallel discrete capacitors, when both-end bonding introduces hum.
β The content presents the Parallel Earth Conductor as a preferred complementary solution, with explicit reference to standards such as BS IEC 61000-5-2.
β The exposition rejects one-end-only termination except as last resort, unless supported by feedthrough filters that preserve enclosure integrity. π
β The material reports that BS EN 50174-2 prescribes both-end termination for shielded Ethernet, updating earlier guidelines.
β The article recalls historical advice from Rolls-Royce Marine to always design with both-end termination and degrade locally only if hum persists.
β The description affirms that capacitive hybrid termination provides wide bandwidth but may fail under lightning surge conditions. π©
β The presentation states that adding Parallel Earth Conductor in parallel to the cable and close routed improves low-frequency performance and complements shield termination.
INSTITUTIONAL CONTEXT
β The authorial responsibility lies with an anonymized institutional specialist who contributes to electromagnetic compatibility education.
β The institutional approach defines termination as the physical and electrical process of connecting cable shields, with etymology in Latin terminare.
β The same approach defines shielding as the structural method of enclosing conductors to block electromagnetic fields, with etymology in Old English scield.
β The concept of bonding is presented as the assurance of conductive continuity between metallic parts, with etymology in Old English bindan. π
β The strategy of Parallel Earth Conductor is described as an auxiliary conductor that runs parallel to the main cable, connected to ground at both ends; the phrase derives from Middle English paralel (alongside) and Old English eorΓ°e (earth).
β The idea of a feedthrough filter is introduced as a filter component integrated at an entry wall, providing direct capacitive coupling to ground; the compound term originates from Old English fΔdan (to pass through) and Latin filtrum (felt for straining). π‘
β The institutional emphasis includes reference to BS IEC 61000-5-2, which governs earthing and cabling practice for industrial environments, and to BS EN 50174-2, which requires structured cabling systems with both-end shield bonding.
β The exposition integrates DEF STAN references, which establish defense standards for electromagnetic compatibility in military equipment.
β The organizational stance repeats that hybrid capacitive termination, Parallel Earth Conductor, and feedthrough filter serve as complementary solutions and never as substitutes for shield termination. π
β The institutional analysis stresses that a design strategy anchored in both-end shield termination remains more cost-effective than late corrective measures in legacy installations.
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