Start from the system
LV or MV is a system and standards decision. Confirm nominal voltage, highest system voltage, phase arrangement, earthing, fault level, protection clearing time and equipment interfaces. A product-page rating cannot replace the project electrical design.
Read the voltage designation correctly
Record the exact U0/U(Um) or other notation used by the governing standard and tender. Similar commercial labels can represent different insulation requirements. Check whether the cable connects phase-to-neutral, phase-to-phase, a converter, transformer, switchgear or motor.
Inputs that affect construction
- Continuous current and permissible voltage drop.
- Short-circuit current, duration and screen or earth-fault duty.
- Installation in air, tray, duct, soil, tunnel or water.
- Single-core or multicore arrangement and bonding method.
- Termination and joint interfaces, bending limits and pulling loads.
- Applicable standard, test category and approval route.
Before issuing an RFQ
- Copy the designation from the latest single-line diagram and specification.
- Flag differences between the BOQ, local practice and cited IEC or BS documents.
- State which party owns sizing and design confirmation.
- Request the proposed construction, rating assumptions and exceptions in writing.
The technical team should confirm the final cable construction against the complete system information. Do not use this guide as an engineering calculation.
This guide supports RFQ preparation and does not replace project engineering or manufacturer technical confirmation.