Three levels, three questions
Power cable standards such as IEC 60502-1 for low voltage and IEC 60502-2 for medium voltage organise testing into three groups. Routine tests are made on every manufactured length and answer the question "is this drum sound?". Sample tests are made on samples cut from a proportion of production and answer "is this batch built to the specified dimensions and materials?". Type tests are made once on a design, and repeated when the design or materials change, and answer "does this construction meet the standard at all?".
Buyers often receive one kind of report and assume it covers the others. A type test report from a respected lab says nothing about the drums on your container. A clean routine test record says nothing about whether the insulation compound will survive thermal ageing. A useful quality plan names which documents you expect at each level, and the desk writes that into the spec sheet before production is booked. For an overview of the full sequence, see testing and inspection.
Routine tests: every drum
Routine tests are cheap enough to run on everything and important enough that nothing should ship without them. For a typical LV or MV power cable they include:
- Conductor resistance: DC resistance measured, corrected to 20 C and compared with the IEC 60228 maximum for the size and class. For copper Class 2, 25 mm2 must not exceed 0.727 ohm/km and 95 mm2 must not exceed 0.193 ohm/km.
- Voltage test: an AC test on the completed cable. For medium voltage, the IEC 60502-2 routine test is 3.5 U0 for 5 minutes without breakdown.
- Partial discharge: for screened MV cable, measured to IEC 60885-3; the routine requirement is no discharge above the declared sensitivity, 10 pC or better, at 1.73 U0.
- Spark test: insulation passed through an electrode on the line to find pinholes and thin spots as the cable is made.
- Length, print and metre marks: checked against the order before the drum is closed.
The output is a test record per drum, tied to the drum number on the label. Ask for these records with the shipping documents, not after a problem appears.
Sample tests: cut and measure
Sample tests take short lengths from a share of the production and examine them in the lab. They catch the problems routine electrical tests cannot see: insulation slightly too thin but still passing the voltage test, a sheath below the specified thickness, a conductor with the right resistance but the wrong number of strands for the class, or an overall diameter that will not fit the glands already bought for the project.
Typical sample tests are conductor construction (strand count and class), insulation and sheath thickness, overall diameter and, for XLPE, checks that the insulation is properly cross-linked. The frequency of sample tests is set by the product standard or by the order; buyers who need more can ask for sample tests on the first drums of each size, or on a sampling plan to ISO 2859-1 at inspection. Our pre-shipment inspection guide explains how sample measurements fit into the final check.
| Level | When it is done | Typical content | What you receive |
|---|---|---|---|
| Routine | Every manufactured length | Conductor resistance, voltage test, partial discharge (MV), spark test, length and print | Test record per drum number |
| Sample | On samples from a share of production | Conductor construction, insulation and sheath thickness, overall diameter, XLPE cure checks | Sample test report per batch or order |
| Type | Once per design, repeated on change | Electrical type tests, thermal ageing of insulation and sheath, fire tests such as IEC 60332-1-2 | Type test report from the plant or an external lab |
Type tests: the design proven once
Type tests are longer and more destructive. They include extended electrical tests on MV cable, ageing of insulation and sheath compounds in ovens followed by mechanical tests, and the non-electrical tests that prove material behaviour. Fire behaviour is also a type-test matter: flame-retardance to IEC 60332-1-2 or IEC 60332-3, smoke density to IEC 61034, halogen acid and acidity to IEC 60754-1 and -2, and circuit integrity to IEC 60331 or BS 6387, each per test report. In the EU, the CPR class on the Declaration of Performance rests on classification testing under EN 50575.
When you review a type test report, check four things: the exact construction tested (conductor, insulation, screen, armour, sheath compounds), the size or size range it covers, the date, and whether the materials have changed since. A report on a 4x25 mm2 cable with one PVC compound does not cover a 4x95 mm2 cable made with a cheaper one. Thermal ageing is the test most often affected by compound changes, and it was ageing, not conductor size, that drove a national building cable recall in Australia in 2013-2014; see insulation ageing failures.
Fibre and data cable equivalents
Fibre cables follow the same logic with different tests. Every fibre on every drum is typically measured with an OTDR for attenuation and length, which acts as the routine record; mechanical and environmental performance of the cable design is proven by type tests against the requirements the order names, such as Telcordia GR-20 for outdoor cable or GR-409 for indoor cable. Patch cords are tested per piece for insertion and return loss against IEC 61753-1 grades. For category cable, the plant's records cover the cable itself; channel and permanent link tests are done after installation. See fibre OTDR test reports for what a good per-drum record contains.
Writing tests into the order
The cleanest way to avoid argument later is to list, on the spec sheet, the documents expected at each level: routine records per drum, sample tests on named sizes, type test reports with their dates, and any witnessed tests. Witnessing a routine voltage or partial discharge test adds a day to the schedule but gives you first-hand evidence. The desk agrees these terms with the plant before copper is booked, and lead time and MOQ are then confirmed in writing for each order; typical ranges are on the MOQ and lead time page. To start a test plan for a project, send the BOQ through the quote form.