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Factory Feeder Cable Check

Derated ampacity + voltage-drop check (XLPE Al 3.5C×240) for this run — both must pass.

Shed feeders grow loads for decades on the same aluminum. Two checks — derated ampacity and voltage drop — decide whether the next machine needs a new cable or just a clear conscience.

149%
Cable utilization
Load current386 A
Derated ampacity259 A (catalogue 305 A)
Voltage drop9.3 V = 2.2% (within 3%)
VerdictUNDERSIZED — next size up

Two checks, both must pass: thermal ampacity (derated) and voltage drop (≤3% for feeders is the common design norm). Long runs usually fail on voltage drop first — the cable that carries the current still can't deliver the volts.

Sources: IS 7098 / manufacturer ampacity tables (typical values); Voltage-drop mV/A/m method

Planning estimate only — interconnection, protection settings and compliance must be reviewed and signed off by a licensed electrical engineer and your utility before energisation.

Use the free Factory Feeder Cable Check online — Derated ampacity + voltage-drop check (XLPE Al 3.5C×240) for this run — both must pass. Runs instantly in your browser: no signup, no upload, mobile-friendly.

About Factory Feeder Cable Check

Shed feeders grow loads for decades on the same aluminum. Two checks — derated ampacity and voltage drop — decide whether the next machine needs a new cable or just a clear conscience.

How to use Factory Feeder Cable Check

  1. 1Pick the cable/conductor and enter the load and run length.
  2. 2Set an honest derating factor.
  3. 3Read utilization, voltage drop and the combined verdict.

Why use Factory Feeder Cable Check?

  • Two checks in one: derated ampacity AND voltage drop — both must pass
  • Real cable data for common Indian sizes and overhead conductors
  • Derating slider for grouping, soil and temperature reality
  • 3% drop norm enforced with the verdict logic

Frequently asked questions

How do I check if a cable can carry my load?+

Two gates: load current (kW ÷ (1.732 × 415 × PF) for three-phase) must stay under the DERATED ampacity, and voltage drop (mV/A/m × current × length) must stay within ~3%. Long runs usually fail on drop while passing ampacity — this tool runs both gates.

Why derate cable ampacity from the catalogue value?+

Catalogue ratings assume one cable, standard soil/air at reference temperature. Reality groups cables in trays, buries them in hot dry soil, and runs Indian summers — each factor multiplies capacity down. 0.8–0.85 combined is a routine honest derating; ignoring it is how 'rated' cables run hot for years.

What voltage drop is acceptable?+

Common design norms: ≤3% for feeders, ≤5% total to the farthest load. Beyond that, motors start poorly and burn out faster, and every percent of drop is I²R energy you buy without using. For revenue circuits (solar plants), designers target 1–2% — lost volts are lost billing.

The cable passes ampacity but fails voltage drop — now what?+

Upsize for the run, not the load: friction... resistance falls with conductor area, so one size up typically halves the drop. Alternatives: shorten the route, raise the distribution voltage for the trunk, or move the load's supply point. Never 'fix' drop by ignoring it — the symptom bills monthly.

Embed Factory Feeder Cable Check on your website

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