Every cable standard divides factory testing into three families, and buyers who know the difference read test documentation far more usefully than buyers who don’t.
Routine tests are performed on every drum before despatch. They’re the non-destructive checks: conductor resistance, and a high-voltage withstand test on the completed cable. If a drum passes, it ships; the certificate for these belongs with your delivery.
Sample tests are made on pieces cut from a manufactured lot — conductor examination, measurement of insulation and sheath thickness, dimensional checks. They confirm the lot is built the way the standard says, without testing every metre to destruction.
Type tests are the heavyweight, done once to prove a design before it enters service — electrical performance, and the long-duration and mechanical tests that would be absurd to repeat on every drum. A type test report doesn’t travel with each order; it exists to show the design has been proven, and you’re entitled to ask to see it.
Conductor resistance deserves a special mention because it’s the easiest number to check and the hardest to fake. IS 8130 fixes the maximum DC resistance for each conductor size — for stranded copper, 1.15 Ω/km at 16 sq mm and 0.727 Ω/km at 25 sq mm, at 20 °C. A cable that reads meaningfully above the standard value is telling you it contains less metal than it should, whatever the label claims. Undersized conductor is the classic economy of the grey market, and a resistance bridge exposes it in minutes.
When ordering, the practical ask is simple: routine test certificates with the despatch, and the type test report for the design if the project is significant. For MV and HV XLPE cables this paperwork is standard practice in any serious tender; for LV projects it’s less often demanded, which is precisely why asking for it filters suppliers. Once the cable arrives, ratings still depend on how it’s installed — the LV XLPE current-rating chart shows the baseline figures the tests stand behind.