What is Armoured Cable?

Armored cable is a high-strength, durable electrical cable featuring an additional metal protective layer. Designed specifically for outdoor and underground installation, its construction effectively withstands mechanical damage and adverse weather conditions, fully meeting relevant installation requirements.

• Conductor: Copper or Aluminum conductors ensure optimal conductivity and flexibility.
• Insulation: XLPE or PVC insulation provides essential thermal stability
• Bedding: A protective PVC or LSZH layer acts as a cushion between the inner cores and the armour.
• Outer Sheath:  A robust, UV-resistant PVC sheath guards against moisture and corrosion.

Armoured Cable Advantage

The primary function of the armour layer is mechanical protection, but its benefits extend beyond just “toughness.”

1. Superior Crush & Impact Resistance

The galvanized steel layer provides a robust shield against accidental shovel strikes during excavation, rock pressure in deep trenches, and heavy vehicle traffic on construction sites.

2. High Tensile Strength (SWA)

For vertical installations (risers) or long cable pulls through ducting, Steel Wire Armour (SWA) acts as a pulling member. It absorbs the tensile load, preventing the copper conductors from stretching or breaking inside the insulation.

3. Earth Continuity  

While not a replacement for a dedicated earth core in all scenarios, a properly terminated armour layer acts as a Circuit Protective Conductor (CPC), providing an essential path for fault currents and enhancing the electrical safety of the system.

4. Rodent Protection (STA)

In rural or agricultural projects, vermin damage is a leading cause of power failure. Our Steel Tape Armour (STA) provides a 100% coverage barrier that rats and termites cannot chew through.

SWA, STA, and AWA: Choosing the Right Types of armoured cable

We offer three distinct armoring options tailored to different customer requirements:

1. 
   

   Steel Wire Armour (SWA Cable)

• Construction: Galvanized steel wires are helically wound around the bedding.
• Best For: General mains supply, cable networks, and systems requiring high flexibility and tensile strength. Common specifications, such as armoured cable 16mm, are frequently kept in stock for immediate deployment in residential sub-mains and light industrial feeds.

The “30-Year Experience” Insight: One common issue with inferior SWA cables is “bird-caging”—where the wires loosen when the cable is bent. We use high-precision planetary armouring machines with consistent back-tension, ensuring the wires stay tight and uniform even at the tightest bend radius.

2. Steel Tape Armour (STA Cable)

• Construction: Double layers of steel tape applied helically.
• Best For: Control cables and power cables where tensile load is low, but crush resistance is high.

While STA cable is generally lighter and more cost-effective than SWA, it is structurally less flexible and not suitable for applications involving significant pulling tension. For a detailed breakdown of which type suits your project best, please read our guide on STA Cable and SWA Cable.

3. Aluminium Wire Armour (AWA Cable)

Crucial for Single Core Cables: You strictly cannot use steel armour on a single-core AC cable. The magnetic field produced by the current would induce eddy currents in the magnetic steel, causing the cable to overheat and fail.

Our Solution: We use non-magnetic Aluminium Wire Armour (AWA) for all single-core specs to ensure magnetic neutrality and thermal stability.

Armoured Cable Specifications

Installation Advice from the ZW Cable Team

As the largest armored cable manufacturer, we possess extensive project experience. Here we summarize three of the most critical installation considerations:

1. Gland Termination: Armoured cables require specific Cable Glands (typically BW for indoor or CW for outdoor/weatherproof). The gland must clamp securely onto the armour wires to ensure earth continuity. We can supply compatible brass glands with your cable order to ensure a perfect fit.
2. Bending Radius: Never force an armoured cable beyond its Minimum Bending Radius (typically 8x the overall diameter). Over-bending can cause the armour wires to splay or the internal insulation to crack.
3. Cold Weather Installation: PVC sheaths become brittle at freezing temperatures. If you are installing in winter (below 0°C), the cable drums should be stored in a heated warehouse for 24 hours prior to laying. Unrolling a frozen cable can shatter the sheath.

Project References: ZW CABLE in Action

• 4 Core Armoured Cable in Singapore: We supplied a regular stock order of 4-Core SWA Armoured Cables to a client in Singapore. The critical requirement was upgrading from standard PVC to LSZH sheathing to meet the BS 6724 standard. Additionally, the client required the cables to pass the rigorous IEC 60332-3-24 vertical flame spread test for use in enclosed commercial buildings. We delivered the full batch with comprehensive third-party test reports, ensuring the cables met the stringent safety regulations without any customs or inspection delays.
• SWA Armoured Cable in Chile: For an open-pit copper mine project, the client reported that standard PVC cables were degrading rapidly due to high UV radiation and mechanical abrasion from rocky terrain. We supplied a customized SWA cable featuring a HDPE outer sheath. This material upgrade provided superior surface hardness and UV stability compared to standard PVC, allowing the cables to maintain structural integrity in the exposed mining environment for over 24 months without sheath failure.
• Medium Voltage STA Cable in the Philippines: For a regional underground project upgrade, the client needed to combat high soil moisture while working under a tight deadline. We supplied 15km of Medium Voltage Steel Tape Armoured (STA) cable, which utilizes double steel tapes as an impenetrable barrier against rodents and internal water-blocking tapes for moisture protection. Crucially, we manufactured and shipped the entire order within just 25 days to meet the project schedule.