The four standards at a glance
A UK specification rarely says "PVC cable" or "armoured cable". It names the standard, and the standard fixes the construction. The pattern is easy to remember once you see it as two pairs: one pair for wiring cable, one pair for armoured cable, and within each pair a PVC version and a low smoke zero halogen (LSZH) version.
| Standard | Typical product | Insulation / sheath | Rating and notes |
|---|---|---|---|
| BS 6004 | 6242Y flat twin and earth, other unarmoured wiring cables | PVC insulation, PVC sheath (Y = PVC) | 300/500 V for 6242Y |
| BS 7211 | 6242B flat twin and earth (LSZH version) | Thermosetting insulation, LSZH sheath (B = LSZH) | 1-2.5 mm2 with Class 1 solid conductors; temperature per standard and BS 7671 |
| BS 5467 | Armoured power cable, Cu/XLPE/PVC/SWA/PVC | XLPE (or similar) insulation, PVC bedding and sheath | 600/1000 V and 1900/3300 V |
| BS 6724 | Armoured power cable, LSZH version | XLPE, EPR or thermoset insulation, LSZH bedding and sheath | 600/1000 V and 1900/3300 V; insulation 90 °C |
One caution on BS 7211. Public datasheets disagree on the operating temperature of 6242B, with some quoting 90 °C and others 70 °C. The desk does not state a figure; it takes the value from the plant's datasheet for the construction and leaves the installation rating to the electrical designer under BS 7671.
Wiring cable: BS 6004 and BS 7211
Flat twin and earth is the cable most associated with UK housing: two insulated conductors and a bare protective conductor laid side by side under a flat sheath. Under BS 6004 it is the PVC/PVC 6242Y type; under BS 7211 it is the 6242B type with thermosetting insulation and an LSZH sheath. The trailing letter is the shortcut: Y for PVC, B for LSZH.
Which one a project needs is a design decision, not a price decision. LSZH sheaths reduce smoke and corrosive gas in a fire and are commonly specified in public buildings, escape routes and enclosed spaces; PVC remains common in domestic work. The tests behind LSZH claims are IEC 61034 smoke density (light transmittance of at least 60%) and IEC 60754-1/-2 acid gas, explained in LSZH sheaths explained. Note that LSZH does not mean the cable produces no smoke, and it says nothing about circuit integrity.
Both types are permanently installed in buildings, so they fall within the CPR regime and need a declared reaction-to-fire class with a DoP. In Great Britain, CE marking continues to be accepted for construction products following a ministerial statement in September 2024, and UKCA is optional. See EU CPR for cables for the class system and documents.
Armoured cable: BS 5467 and BS 6724
BS 5467 and BS 6724 describe the same armoured construction family, typically written Cu/XLPE/PVC/SWA/PVC or Cu/XLPE/LSF/SWA/LSF in trade shorthand. The conductor is copper (or aluminium where specified), insulated with XLPE, laid up with fillers, covered with a bedding layer, armoured and sheathed. The difference is the bedding and sheath: PVC in BS 5467, LSZH in BS 6724.
- Multicore cables use galvanised steel wire armour (SWA).
- Single-core cables for AC circuits use aluminium wire armour (AWA), because steel armour around a single AC conductor would heat up from induced currents. The reasoning is in AWA armour on single-core cables.
- Armour as protective conductor: armour resistance matters, because designers may rely on it for earthing. It is a routine check, not a detail.
Both standards cover 600/1000 V and 1900/3300 V ratings. Current rating depends on installation method and is confirmed by the designer under BS 7671. The armoured cables page describes the constructions the desk sources, including which armour types need a specialised partner plant.
Neither standard makes a cable fire-resistant. Circuits that must keep working in a fire, such as fire alarm, emergency lighting, smoke extraction and sprinkler pumps, are specified to separate fire tests: BS 6387 CWZ categories for flame, water and mechanical shock, and BS 8519 Category 1, 2 or 3 for life safety and firefighting systems, each per test report. A BS 6724 cable with an LSZH sheath has better smoke and acid gas behaviour than BS 5467, but it is still a reaction-to-fire question, not circuit integrity. The BS 6387 CWZ and BS 8519 article covers what those tests prove and how to word them on an order.
BASEC approval and what it proves
BASEC is the UK's cable certification body. Its own guidance is direct: only cable marked with the BASEC name is covered by BASEC approval, and cable that only quotes a standard number should be treated with caution. A sheath print reading "BS 6724" is a claim by the maker; a BASEC approval held by the partner plant for that construction is independent evidence.
BASEC has also published warnings that show why this matters. In one case, armoured cable described as BS 5467 had no BASEC approval, and testing found conductor and armour resistance above the limits, with an effective cross-section up to two sizes smaller than marked. That kind of shortfall cannot be seen by eye; it shows up in a conductor resistance test against IEC 60228, which is why the desk asks for resistance records per drum. More on this in undersized conductors.
- Ask whether the partner plant holds BASEC approval for the exact standard, construction and size range.
- Check the approval in BASEC's public records per order.
- Compare the sheath print on a sample with the approval: standard, size, cores and the BASEC name.
- Ask for conductor and armour resistance records for the production lot.
Ordering UK-standard cable through the desk
BS 5467 and BS 6724 armoured cable is usually supplied on drums; twin and earth on coils or small drums for wholesalers and electrical distributors. Plan colour, print text, drum length and any private label at the RFQ stage, and state whether BASEC approval is required, because that narrows the partner plants that can quote. Typical MOQ ranges for power cable are around 500 m per size, with some plants accepting 100 m, confirmed in writing for each order; see the MOQ and lead time page and send the line items through the quote form.