What is armoured cable (SWA), in one line?
Quick answer: Armoured cable — usually SWA (Steel Wire Armoured) in South Africa — is a tough, multi-core power cable wrapped in a layer of galvanised steel wires under its outer sheath. That steel armour protects the conductors from being crushed, dug into or chewed through, which is exactly why SWA is the standard cable for running power underground, outdoors and to outbuildings — think a feed to a garage, borehole pump, electric gate, granny flat or sub-distribution board.
What does SWA cable actually look like (and what each layer does)?
SWA cable is built in layers, from the copper out. Knowing the parts makes choosing the right one far easier:
- Copper conductors (cores): the actual current-carrying wires. The cable is sold by core size (e.g. 4mm²) and core count (2, 3 or 4 core).
- XLPE / PVC insulation: colour-coded insulation around each core so you can identify live, neutral and earth.
- Inner bedding: a sheath that cushions the cores before the armour goes on.
- Steel Wire Armour (the “SWA”): a basket of galvanised steel wires. This is the mechanical protection — and it can also serve as the circuit’s earth when terminated correctly with the right gland.
- Black PVC outer sheath: the UV- and moisture-resistant jacket you see on the outside.
When do you actually need armoured cable in South Africa?
Short answer: use SWA wherever a cable could be physically damaged or is exposed to the elements — especially anything buried or run outdoors. Typical jobs where SWA is the right call:
- Running power underground between buildings (house to garage, cottage, workshop or store).
- Feeding a sub-distribution board in an outbuilding or granny flat.
- Supplying a borehole or pool pump, electric gate motor, or outdoor lighting.
- Connecting a generator, inverter or change-over feed where the cable runs outside.
- Any run that crosses a driveway, garden or area where it could be dug into later.
For protected runs inside walls and roof spaces, surfix/house wire is normal — SWA is about mechanical and environmental protection where ordinary cable would be at risk.
What size armoured cable do I need? (the part everyone searches for)
Direct answer: the right SWA size depends on three things — the load (amps), the cable run length (longer runs need a bigger size to limit volt drop), and whether it’s a single-phase or three-phase supply (which sets the core count). The table below is a practical starting point for common SA jobs. Your registered electrician must confirm the final size against SANS 10142-1, the actual load and the run length — use this to understand the ballpark, not as a wiring instruction.
| SWA size | Rough current capacity* | Typical use | Cores |
|---|---|---|---|
| 1.5mm² | ~18–20 A | Outdoor lights, small gate motor, control feeds | 3 core |
| 2.5mm² | ~24–27 A | Plug circuit / small pump in an outbuilding | 3 / 4 core |
| 4mm² | ~32–36 A | Cottage feed, geyser, larger pump | 3 / 4 core |
| 6mm² | ~40–46 A | Garage / granny-flat sub-board (light load) | 3 / 4 core |
| 10mm² | ~55–63 A | Sub-board feed, longer runs | 2 / 3 / 4 core |
| 16mm² | ~75–85 A | Main feed to an outbuilding or larger sub-board | 2 / 3 / 4 core |
| 25mm²+ | ~100 A and up | Heavy three-phase / long main feeds | 4 core |
*Indicative free-air / buried ratings only. Real ampacity changes with installation method, grouping, soil/ambient temperature and run length. Always size to SANS 10142-1 with your electrician.
2-core vs 3-core vs 4-core: which do you choose?
- 2 core — single-phase circuits where the steel armour is used as the earth (live + neutral, armour = earth).
- 3 core — the everyday single-phase choice for SA: live, neutral and a dedicated earth core.
- 4 core — three-phase supplies (3 phases + neutral), used for bigger loads, motors and three-phase boards.
Armoured cable prices in South Africa — real per-metre numbers
Quick answer: SWA is sold by the metre, so you only buy what your run needs.
Below are current Lite-Glo per-metre prices for the most-bought 3- and 4-core SWA sizes — a useful reality check when you’re budgeting a job.
| SWA cable | Price (per metre) |
|---|---|
| SWA 1.5mm² 3 core | R38.50 |
| SWA 2.5mm² 3 core | R50.00 |
| SWA 4mm² 3 core | R66.00 |
| SWA 6mm² 4 core | R115.00 |
| SWA 10mm² 4 core | R175.00 |
| SWA 16mm² 4 core | R250.00 |
| SWA 25mm² 4 core | R400.00 |
*Prices shown are per metre and may change, check the live product page for the current rate as per your tier and to order the exact length you need.
Shop SWA armoured cable by the metre
Order the exact size and length for your run — cut to the metre, in stock, delivered nationwide:
How to install armoured cable correctly (and safely)
Answer: SWA termination is a job for a registered electrician, because the steel armour usually has to be earthed through a proper brass SWA gland — get this wrong and the cable isn’t protected the way it should be. The key principles:
- Glands matter: each end is terminated with the correct-size SWA gland so the armour is clamped and bonded to earth. Use the matching gland for the cable size.
- Burial depth: underground SWA should be laid at a safe depth (commonly ~500–600mm, deeper under driveways), on a sand bed, with cable warning tape above it so future digging finds the tape first.
- Bending radius: don’t kink it — SWA needs a generous bend radius, especially in the larger sizes.
- Volt drop: on long runs, size up so the voltage at the far end stays within limits.
Armoured cable and load-shedding / backup power
With so many SA homes and sites now running inverters, batteries and generators, SWA has become the go-to for the cabling between a backup system, a change-over switch and an outbuilding board — particularly where that cable runs outside or underground. If you’re wiring a generator point at a garage or feeding a separate inverter shed, SWA is almost always the correct cable for the exposed section. Size it for the full backup load, not just today’s draw, so you don’t have to re-pull cable when the system grows.
Frequently asked questions about armoured (SWA) cable
What does SWA stand for?
SWA stands for Steel Wire Armoured — the layer of galvanised steel wires wrapped around the insulated cores that gives the cable its mechanical protection.
Can armoured cable be buried directly in the ground?
Yes — SWA is designed to be laid underground. Best practice is to bury it on a sand bed at a safe depth with cable warning tape above it, and to terminate both ends with proper SWA glands. Your electrician will confirm depth and method to SANS 10142-1.
Do I need a gland for armoured cable?
Yes. Each end of an SWA run is terminated with a brass SWA gland sized to the cable. The gland clamps the steel armour and lets it be bonded to earth, which is part of what makes the cable safe.
What size armoured cable for a garage or sub-board?
It depends on the load and the run length, but a light garage / granny-flat sub-board is often fed with 6mm² or 10mm² SWA, and a larger or longer feed with 16mm². These are starting points only — your registered electrician must confirm the size for your actual load,
distance and supply.
Is armoured cable sold by the metre?
Yes — Lite-Glo sells SWA cable per metre, so you order exactly the length your run needs rather than a full drum.
Can I install armoured cable myself?
No. In South Africa, fixed electrical work must be done by a qualified, registered electrician and certified with a Certificate of Compliance (CoC). You can buy the cable and plan the run, but the termination, earthing and connection must be done by a professional.
What’s the difference between 3-core and 4-core armoured cable?
3-core SWA (live, neutral, earth) is the common single-phase choice; 4-core SWA (three phases + neutral) is used for three-phase supplies and bigger loads such as motors and three-phase boards.
⚠️ Safety & Compliance Notice
All electrical installations in South Africa must comply with SANS 10142-1 (Wiring Code) and the Occupational Health & Safety Act. Work must be carried out by a qualified, registered electrician. This article is for general educational purposes only. It does not replace professional advice, and Lite-Glo accepts no liability for how this information is used. Always obtain a valid Certificate of Compliance (CoC) for any electrical work.
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