Understand the interface decision

A screen can control interference while other conductors provide protective bonding. Treating those functions as interchangeable can produce poor noise performance or an unsafe fault path. Long field cables, converter switching and differences in ground potential make the full installation relevant to the decision.

Cable selection joins electrical performance, installation conditions and termination requirements. A calculation for one purpose does not settle the others. Keep the actual route and equipment interface attached to the design review, so later changes remain visible.

Put these inputs in the review record

Use a project-specific worksheet to capture the following information. For each entry, name the document, revision and person responsible for resolving any uncertainty.

• Cable-screen construction and equipment termination instructions. Identify the exact configuration and the supporting document.
• Protective-bonding arrangement separate from signal-screen functions. Keep the design assumptions visible in the project record.
• Interference sources and affected measurement or communication circuits. Name the responsible reviewer and resolve any missing information.
• Potential differences and the approved EMC installation design. State how this entry will be verified during acceptance.

Define the acceptance boundary

Document the selected termination method at both ends and any intermediate boundary. Do not change it as an informal troubleshooting experiment without reviewing the consequences. The responsible designer should define how the arrangement will be checked.

A clear drawing should distinguish screen, protective conductor and signal reference. This avoids a technician removing a protective connection while trying to cure a measurement problem that needs a different solution.