Understand the interface decision

Dividing total current by the number of cables assumes a sharing condition that the installation must support. Unequal heating can increase the problem and complicate protective coordination. The designer should assess the complete parallel arrangement, including each branch connection and its installation environment.

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.

• Conductor material, cross-section and effective branch length. Identify the exact configuration and the supporting document.
• Routing arrangement and relevant inductive effects. Keep the design assumptions visible in the project record.
• Termination type, condition and approved connection method. Name the responsible reviewer and resolve any missing information.
• Branch current measurements and thermal acceptance conditions. State how this entry will be verified during acceptance.

Define the acceptance boundary

Do not approve parallel cables from a total-current reading alone. Require the design basis and the verification method for individual branches. A disconnected or impaired branch also needs consideration in the protective and operating response.

At acceptance, associate each measured branch with its cable identity. Keep current and temperature evidence under comparable loading so the record can reveal unequal sharing instead of averaging it away.