Professional cable manufacturer
Standards referenced: IEC 60502-1 • IEC 60502-2 • BS 5467 • BS 6724 • BS 7846 • IEC 60228 • IEC 60332 • IEC 60754 • EN 50618
Why Cable Markings Matter More Than You Think
Every certified power cable carries a printed code on its outer sheath. It lists the conductor, insulation, armour, sheath material, voltage rating, standard number, manufacturer, and a running metre mark. For procurement engineers and project managers, that line of text is your first — and often only — checkpoint before installation.
Get it wrong and the cost stacks up fast:
- A PVC sheath mistaken for LSZH releases toxic halogen gas in a fire, contaminating ventilation systems and putting lives at risk.
- XLPE insulation swapped for PVC drops the continuous operating temperature from 90°C to 70°C. Overload it and the insulation breaks down.
- SWA (steel wire armour) used on single-core AC circuits instead of AWA creates eddy current heating that can melt the armour from the inside.
Whether you are ordering CU/XLPE/SWA/PVC 0.6/1kV armoured power cable or BS 6724 LSZH halogen-free cable, understanding the marking code helps you verify the right product arrives on site.
Who this guide is for
Power engineers, electrical procurement teams, site quality inspectors, and distribution system designers who handle cable receiving, stock management, or project installation.
Breaking Down a Cable Marking: What Each Part Means
Here is a typical UK-standard power cable print:
SORIVO CU/XLPE/SWA/PVC 0.6/1kV 3x70mm² BS 5467 2025-06 METRE 000125
Reading right to left, every field maps to a purchasing or installation decision:
| Marking Field | What It Tells You | Why It Matters |
|---|---|---|
SORIVO | Manufacturer brand | Traceability and certification consistency |
CU/XLPE/SWA/PVC | Construction code (conductor/insulation/armour/sheath) | Specifies full build structure at a glance |
0.6/1kV | Rated voltage U&sub0;/U | System voltage match (LV vs MV application) |
3x70mm² | Cores x cross-section | Current capacity and electrical design basis |
BS 5467 | Product standard | Compliance tier (BS 5467 PVC vs BS 6724 LSZH) |
2025-06 | Manufacturing date | Batch traceability and warranty validation |
METRE 000125 | Running metre mark | Precision cable cutting and remnant management |
Key difference
Unlike consumer labels, cable markings are permanent identifiers. They must remain legible for the cable's entire service life. Both IEC 60227 and BS 7671 set clear requirements for print durability and readability.
Decoding the Construction Code Layer by Layer
The construction code is the most critical part of the marking and the most commonly misread. Each material layer is separated by a slash (/). For a detailed comparison of armoured versus unarmoured cables, see our Armoured Cable vs Unarmoured guide.
Layer 1: Conductor
| Code | Material | Standard | Key Note |
|---|---|---|---|
CU | Copper | IEC 60228 | Default when no prefix is shown |
AL | Aluminium | IEC 60228 | Weighs about 30% of copper, carries ~78% of the current |
| (none) | Copper (assumed) | — | Most LV cables omit the conductor prefix |
The standard number in the marking hints at the conductor stranding class, though it is not printed directly:
- Class 1 – solid conductor, fixed installations only
- Class 2 – stranded, for fixed-installation power cables
- Class 5/6 – flexible, for moving equipment and connections (per IEC 60228)
Field check
Strip 10 cm of sheath and count the wire strands. A Class 2 70mm² copper conductor has roughly 19-21 strands. A Class 5 equivalent has 56 or more. This takes two minutes and tells you immediately if the cable matches the order.
Layer 2: Insulation
| Code | Material | Temp Rating | Voltage Range | Typical Use |
|---|---|---|---|---|
XLPE | Cross-linked polyethylene | 90°C cont. / 250°C short-circuit | 0.6/1kV – 35kV | Mainstream power cable insulation |
PVC | Polyvinyl chloride | 70°C cont. / 160°C short-circuit | Up to 0.6/1kV | Budget building wire, not for high temp or outdoor |
XLPO | Cross-linked polyolefin | 90°C – 125°C | 1.5kV DC | Solar cable insulation (EN 50618) |
EPR | Ethylene propylene rubber | 90°C | 0.6/1kV – 33kV | Ships, nuclear plants, high-flexibility needs |
LSZH | Low smoke zero halogen (compound) | 90°C | Various | Not a single material – used with XLPE or XLPO |
Common mistake
LSZH is a burning behaviour classification, not a specific insulation material. Write "LSZH XLPE" or "LSZH compound", never just "LSZH" as a material name. On a cable marking,
LSZH in the sheath position means zero halogen outer layer; in the insulation position it typically refers to a halogen-free cross-linked compound.Layer 3 + 4: Armour
| Code | Material | Best For | Limitation |
|---|---|---|---|
SWA | Galvanised steel wire armour | Direct burial, high mechanical protection | Eddy current in single-core AC – multicore only |
AWA | Aluminium wire armour | Single-core AC, corrosive environments | Lower mechanical strength than SWA |
STA | Steel tape armour (single layer) | Light mechanical protection | Lower impact resistance than SWA |
SWB | Steel wire armour (bedded) | Subsea, vertical runs, high tension | Most expensive, for tension-rated applications |
For a head-to-head comparison of armour types, read our SWA vs AWA vs STA Armoured Cable guide.
SWA vs AWA – Quick Decision Tree
Need armour protection?
+-- Single-core AC? -> Use AWA (aluminium, non-magnetic)
+-- Multicore?
+-- Direct burial / road crossing -> SWA (steel, can double as earth conductor)
+-- Corrosive soil -> AWA or SWA with enhanced outer sheath
+-- Rodent/termite protection only -> STA or minimum SWA specLayer 5: Outer Sheath
| Code | Material | Flame Rating | Halogen | Typical Life |
|---|---|---|---|---|
PVC | Polyvinyl chloride | IEC 60332-1 (self-extinguishing) | Halogenated | 15-25 years |
LSZH | Low smoke zero halogen compound | IEC 60332-1/3 + IEC 60754 | Zero halogen (HCl < 0.5%) | 25+ years |
PE | Polyethylene | Non-flammable but melts/drips | Zero halogen | 30+ years |
PUR | Polyurethane | IEC 60332-1 | Zero halogen | 10-15 years (drag-chain wear) |
Using the Standard Number to Judge Compliance
The standard printed on the cable is the quickest way to separate a certified product from a commodity cable.
British Standard Series (BS)
| Standard | Insulation | Sheath | Armour | Voltage | Typical Application |
|---|---|---|---|---|---|
BS 5467 | XLPE | PVC | SWA/AWA | 0.6/1kV | General distribution, industrial |
BS 6724 | XLPE | LSZH | SWA/AWA | 0.6/1kV | Buildings, tunnels, metro |
BS 7846 | XLPE | LSZH | SWA | 0.6/1kV | Fire circuits (see BS 6387 CWZ fire cable, 30/60/120 min) |
BS 5308 | PVC/PE | PVC/LSZH | Screened (non-armoured) | — | Instrumentation and control signals |
IEC / EN Series
| Standard | Scope | Key Tests |
|---|---|---|
IEC 60502-1 | 0.6/1kV extruded insulation power cables | Partial discharge, dielectric, bending |
IEC 60502-2 | 6-30kV medium voltage cables | Same + impulse voltage, thermal cycling |
EN 50618 | Solar cables | 1000h UV, ozone, 125°C heat ageing |
IEC 62930 | Solar cables (international) | Same as EN 50618, 1500V DC |
The Certification Pyramid
Third-party certification (TUV / UL / BASEC / KEMA)
+-- Full type testing + factory audit
+-- Self-declaration CE (manufacturer declares compliance)
+-- No certification markIf the marking carries a third-party mark such as BASEC or TUV, the cable has passed independent testing and factory inspection. Many EPC contracts mandate "BASEC approved" or "TUV certified" explicitly. Self-declared CE compliance alone will not satisfy those tender conditions.
Four-Second Field ID: Spot SWA, AWA, XLPE, LSZH Fast
When you are standing in a warehouse or on a trench, here is how to read the key codes in under ten seconds:
- Find XLPE or PVC – in the insulation position. XLPE means 90°C rated. PVC means 70°C rated and roughly 15-20% lower current capacity for the same cross-section.
- Find LSZH or PVC – in the sheath position. LSZH is zero halogen (check for BS 6724). PVC is halogenated (check for BS 5467).
- Find SWA or AWA – the armour layer. SWA = steel (magnetic), AWA = aluminium (non-magnetic).
- Read the standard – BS 5467 (XLPE/PVC) = general purpose. BS 6724 (XLPE/LSZH) = halogen-free safety grade.
If the print is worn or unclear, use these physical checks to confirm:
| What to Check | How | Expected Result |
|---|---|---|
| XLPE vs PVC (insulation) | Heat with a hot air gun to ~150°C | XLPE holds shape, PVC softens |
| LSZH vs PVC (sheath) | Burn a small piece, watch the smoke | LSZH: thin white smoke. PVC: thick black, acrid |
| SWA vs AWA (armour) | Strip sheath, use a magnet | SWA sticks, AWA does not |
| Tinned vs bare copper (conductor) | Strip insulation, check surface | Tinned: silver-white. Bare: reddish-copper |
The Real Cost of Misreading a Marking
| Cost Factor | PVC Mistaken for LSZH | AWA Mistaken for SWA | 600V Mistaken for 1kV |
|---|---|---|---|
| Replacement labour | Strip & replace 300m, 2 workers x 3 days ≈ USD 4,200 | Cut out & re-joint, 2 workers x 1 day ≈ USD 1,400 | Full replacement & removal ≈ USD 5,800 |
| Downtime loss | 8h production downtime ≈ USD 8,000-25,000 | 4h downtime ≈ USD 4,000-12,000 | 8h downtime + clearance ≈ USD 10,000-30,000 |
| Compliance penalty | Fire inspection fail + rectification + fine up to USD 50,000 | Eddy current overheat → cable fire risk | Insulation breakdown → short circuit |
| 25-year TCO impact | Insurance premiums 15-30% higher annually | ~10% of cable replaced per year | Service life drops to 5-8 years |
Real case
A European data centre retrofit project received BS 5467 (PVC) cable instead of the specified BS 6724 (LSZH). The error was caught during smoke density testing at fire inspection. All 800m of cable in the riser had to be stripped out and replaced with LSZH. Direct cost plus delay penalties: approximately EUR 120,000.
Decision Matrix: Which Cable for Your Environment?
Quick Selector – Cable Construction by Environment
| Environment | Recommended Construction | Key Standard |
|---|---|---|
| Direct burial, general | CU/XLPE/SWA/PVC | BS 5467 |
| Building interior, public area | CU/XLPE/SWA/LSZH | BS 6724 |
| Single-core AC feeder | CU/XLPE/AWA/PVC or LSZH | BS 5467 / BS 6724 |
| Fire alarm / emergency circuit | CU/XLPE/SWA/LSZH (fire-rated) | BS 7846 (PH30-PH120) |
| Subsea / high tension pull | CU/XLPE/SWB/LSZH | IEC 60502 + bespoke |
| Corrosive / chemical plant | CU/XLPE/AWA/LSZH | BS 6724 |
| Solar farm, outdoor exposed | Tinned copper/XLPO/LSZH | EN 50618 (H1Z2Z2-K) |
How to use: Find your installation environment in the left column, then check the matching construction code and standard. Cross-reference with the voltage and core count required for your design.
SORIVO Marking Standard: Traceability in Every Metre
Comparison: SORIVO Premium vs Market Economy Cables
| Feature | Economy Grade | SORIVO Premium |
|---|---|---|
| Conductor | Bare copper (oxidises, contact resistance rises) | Tinned copper (IEC 60228 Class 2/5, corrosion resistant) |
| Insulation | PVC (70°C, ~15 yr life) | XLPE or LSZH XLPE (90°C, 25 yr design life) |
| Sheath | PVC (releases halogen acid gas) | LSZH (IEC 60754 zero halogen + IEC 61034 transmittance ≥60%) |
| Armour | Thin steel tape, prone to rust | SWA galvanised or AWA aluminium, thickness ≥ standard minimum |
| Marking traceability | None or illegible | Continuous metre marks + batch code + date, fully traceable |
| Certification | Self-declared CE | TUV / UL / BASEC / KEMA third-party certified |
| Warranty | 1-5 years | 25 years |
SORIVO power cables carry a complete marking like this:
SORIVO CU/XLPE/SWA/PVC 0.6/1kV 3x70mm² BS 5467 2025-06-15 METRE 000125
Every reel goes through print adhesion testing (BS EN 50363) before dispatch, so the marking survives pulling, bending, and conduit installation without rubbing off. Metre marks are incremented every 1m with a tolerance of +/-0.5%, giving you accurate length control for both installation and inventory.
Need Certified Power Cables?
SORIVO supplies the full range of BS 5467, BS 6724, and BS 7846 armoured cables. Every coil is print-checked, high-voltage tested, and metre-mark calibrated before leaving the factory.
Request batch test reports or free technical selection support:
sale@sorivocable.com | +86 19282905529
Frequently Asked Questions About Cable Markings
Q1: What does "0.6/1kV" mean on a cable marking?
The rating printed as "0.6/1kV" gives the cable's voltage limits. U&sub0; (0.6kV) is the conductor-to-earth or conductor-to-screen rated voltage. U (1kV) is the conductor-to-conductor rated voltage. For IEC 60502-1 low-voltage cables, 0.6/1kV is the most common class, corresponding to a maximum system voltage of 1.2kV. If your system runs at 690V (typical in some industrial installations), 0.6/1kV cable is still the correct choice.
Q2: How do BS 5467 and BS 6724 markings differ?
BS 5467 specifies XLPE insulation with a PVC sheath – the marking will show "PVC" and "BS 5467". BS 6724 specifies XLPE insulation with an LSZH sheath – the marking will show "LSZH" and "BS 6724". Conductor sizes, strand counts, and armour types are identical between the two standards. The only difference is the sheath material: BS 6724 is zero halogen, making it mandatory for building interiors, tunnels, and public spaces.
Q3: Why can't I use SWA on single-core AC cables?
The alternating current in a single-core cable creates a time-varying magnetic field around the conductor. Steel wire armour is magnetic, so that field induces eddy currents in the armour, which generate heat. The heating is proportional to the square of the current and can raise the armour temperature by 30-50°C above ambient. This reduces the cable's current rating and accelerates insulation ageing. The fix is to use AWA (aluminium wire armour, non-magnetic) or a non-magnetic stainless steel armour.
Q4: What should I do if the cable marking is smudged or illegible?
Both IEC 60227 and BS 7671 require that cable markings remain legible under normal installation and service conditions. If a delivered cable shows illegible printing, reject it or reclassify it for non-critical use. On site, you have three practical workarounds: (1) fit heat-shrink marker sleeves at both ends, (2) use UV-rated cable tie markers rated for the ambient temperature, or (3) apply adhesive labels every 5m with a handheld label printer. None of these fully replace factory-printed identification, but they provide a workable audit trail.
Q5: How do running metre marks help during installation?
Continuous metre marks serve three practical purposes. During installation: the crew cuts exactly to the design length. A 200m loop saves 3-5m of waste compared to measuring by tape. For inventory: the warehouse checks delivered length against the last metre mark to verify you received what you paid for. For maintenance: when a fault is located, the metre mark at the fault point is recorded. The repair crew goes straight to that position instead of continuity-testing the whole run.