Armored Power Cables: Types & Selection

Armored power cables feature a metal layer between the inner and outer sheaths. This armor provides mechanical protection against crushing and impacts, while also serving as an electrical ground.

Choosing the wrong type can lead to cable failure or overheating. Here is what you need to know in under three minutes.

1. The 4 Core Types of Armor

The material and structure of the armor determine its strength and flexibility:

• Steel Wire Armor (SWA): Features a layer of round galvanized steel wires. It offers incredible tensile (pulling) strength.

• Best for: Vertical shafts, high-drop locations, and deep underground trenches.

• Steel Tape Armor (STA): Features overlapping steel tapes. It prioritizes crush and puncture resistance over pulling strength.

• Best for: Direct burial under roads or pathways with heavy surface traffic.

• Aluminum Wire Armor (AWA): Uses non-magnetic aluminum.

• The Rule: Alternating Current (AC) creates magnetic fields. In single-core cables, steel armor causes overheating due to magnetic eddy currents. Therefore, single-core AC cables must use AWA.

• Metal Wire Braid: A woven mesh of fine wire that provides basic protection while remaining highly flexible.

• Best for: Marine vessels, offshore rigs, and moving machinery.

2. Global Naming Cheat Sheet

Depending on your project's region, the blueprints will use different codes:

• UK / International (BS/IEC): Looks for BS 5467 (Standard PVC) or BS 6724 (Low Smoke Zero Halogen - LSZH for public safety).

• North America (NEC): Look for MC (Metal-Clad) cables (includes a dedicated green ground wire) or AC (Armored Cable/BX).

• China (GB/T): Look for YJV22 (Steel Tape/STA) or YJV32 (Steel Wire/SWA).

3. Quick Selection Matrix