Two tests under one number
IEC 60332 is a family of tests that measure how far flame travels along a cable held vertically in a test rig. It does not measure smoke, acid gas or whether the circuit keeps working; those belong to IEC 61034, IEC 60754 and IEC 60331. What it does tell you is whether a cable, once ignited, carries the fire up a riser or along a tray, or stops it close to the source.
The family splits into two parts that buyers often mix up. IEC 60332-1-2 tests a single insulated wire or cable. IEC 60332-3 tests a bunch of cables mounted together on a ladder in a test chamber. A cable can pass the single cable test and still fail the bunched test, because a bundle of cables burns very differently from a single length. When a quote simply says "flame-retardant", the first question is: to which part, and for the bunched test, to which category.
IEC 60332-1-2: the single cable test
In IEC 60332-1-2 one sample is clamped vertically and exposed to a standard burner flame for a set time depending on its diameter. After the flame is removed, the charred length is measured and compared with the limits of the standard. It is a modest test, well suited to building wire, flexible cords and smaller cables that are usually installed singly or in small groups.
The test matters well beyond its own scope. In the EU CPR system, EN 60332-1-2 is the only fire test for class Eca and one of the two tests used for classes B1ca to Dca, alongside EN 50399. Many national wiring rules and project specifications also call for it as a minimum for PVC and LSZH cables. Most partner plants can supply standard PVC and LSZH constructions flame-retardant to IEC 60332-1-2 per test report, and the report should name the exact construction tested.
IEC 60332-3: the bunched cable categories
IEC 60332-3 is a much more demanding test. Lengths of cable are fixed side by side on a vertical ladder in a chamber described in IEC 60332-3-10, and the amount of cable is set by the volume of non-metallic material (insulation, fillers, sheath) per metre of the test ladder. The more non-metallic material, the more fuel, the harder the test. The cables are exposed to a burner for a set time, and the result is a pass when the charred portion has not reached a height of 2.5 m above the bottom edge of the burner.
| Part | Category | Non-metallic volume per metre | Flame application |
|---|---|---|---|
| IEC 60332-3-21 | A F/R | 7 L/m | Per the standard; this part applies only to power cables above 35 mm2 |
| IEC 60332-3-22 | A | 7 L/m | 40 min |
| IEC 60332-3-23 | B | 3.5 L/m | 40 min |
| IEC 60332-3-24 | C | 1.5 L/m | 20 min |
| IEC 60332-3-25 | D | 0.5 L/m | 20 min |
Category A is the most severe and category D the lightest. The category on a test report should be read as the fuel load the cable was proven against, not as a grade of quality. A specification that calls for category C because the cable trays carry modest loads is satisfied by a category C report; a specification for dense vertical risers in a plant room may call for category A. The choice is made by the designer from the expected installation, then confirmed by the project engineer.
What changes in the construction
Passing the bunched test usually changes the bill of materials, not just the paperwork. Plants use flame-retardant PVC or LSZH compounds with higher filler content for the sheath and sometimes for the fillers and bedding, and they may change the binder tapes. For LSZH cables the compound has to pass the bunched test while also meeting low smoke and acid gas requirements, which makes the compound choice tighter. Those changes affect weight, diameter, flexibility and price per metre, so two quotes for "flame-retardant cable" can differ simply because one is designed for IEC 60332-1-2 and the other for IEC 60332-3 category A.
The test result also belongs to the tested construction. A category A report on a 4-core 95 mm2 cable does not automatically cover a 2-core 2.5 mm2 cable from the same family, because the ratio of non-metallic material to copper is completely different. Ask the plant which sizes and core counts the report covers and how the family was grouped; the desk checks this on the report itself, as part of the routine described on our testing and inspection page.
Production consistency matters as much as the original report. A plant that passed a bunched test two years ago with one compound supplier may have changed supplier since, and the sheath may now behave differently in a fire. On repeat orders the desk asks whether the compound and its supplier are unchanged since the report was issued, and records the compound batch on the drum documents. Where a project specification requires it, a sample from the production run can be sent to an independent laboratory for a repeat test before shipment.
How buyers check flame-retardant claims
- Name the part and category: IEC 60332-1-2, or IEC 60332-3 with the category letter.
- Read the report, not the sheath print: the report should name the laboratory, the construction tested, the sample sizes, the date and the result.
- Match the construction: sheath compound, core count and size range on the spec sheet should fall within what was tested.
- Keep the scope separate: a flame test says nothing about circuit integrity or smoke; if you need those, ask for IEC 60331, IEC 61034 and IEC 60754 reports as well.
- Plan the time: if no report exists for your construction, a new bunched test adds time and cost before production, so mention it at the enquiry stage.
For the place of IEC 60332 among the other fire routes, see the fire performance classes page and the CPR classes guide. Constructions with LSZH sheaths are on the fire-resistant cables page, and standard power constructions on the LV power cable page. When you send a request through the quote form, give the flame test part and category per cable type; the desk confirms which partner plant holds a matching report before a sample or trial drum is agreed.