What Is Steel Wire Armoured Cable?

Are you confused about which cable to use for difficult and demanding applications? Well, this blog is for you. Picking the wrong type can lead to failures, safety risks, and costly repairs.

In this blog, we will cover Steel Wire Armoured cable thoroughly, so that you can make informed decisions while staying safe and powering your projects with confidence. So, keep reading!

1) What Is Steel Wire Armoured Cable (SWA)?

Steel Wire Armoured Cables (SWA) are a kind of electrical power cable that comes with an extra protective layer made of steel wire which is wrapped around the inner cores. This additional armor serves as extra mechanical protection and makes the cable very resistant to damage from impacts, tension, and even environmental stress.

Broadly speaking, Steel Wire Armoured Cable or SWA cable is classified as one of the strongest and toughest types of power cables. Their primary function is to carry electricity while safeguarding inner wires from damage. However, their usage can often be seen in outdoor settings where reliability and safety are most important.

Significantly, the distinct feature of SWA cable is its steel wire. These are layers of strong steel wires encasing the inner cables. They protect the cables from physical threats such as crushing, pulling, or impacts.

Why Is It Called “Armoured”?

The term “armoured” is used because the outer steel layer protects the wire just like an armour ( a shield that protects the soldiers). Well, steel wire armour resists the outside pressure and so protects the electrical conductor inside.

It provides a certain degree of mechanical protection so that the cable can be buried underground or placed in harsh environments without suffering damage.

Most importantly, SWA cables can also be used inside as well as outside buildings because they can withstand moisture, physical pressure, corrosion and more. Because of this, they are an ideal fit when you need something dependable and durable.

2) Key Components of SWA Cable

Alright! While Steel Wire Armoured (SWA) cables possess strength, they generate trustworthy reliability due to their structure. Let’s examine the key components of the SWA cable, so keep in touch!

i) Conductor – The Power Carrier

A key component of SWA cable is the conductor. This conductor is located in the midsection of the cable. It is usually composed of aluminium or copper. Its task is quite straightforward—to transmit electric current. However, Copper conducts electricity better, so it is preferred, but aluminium is also beneficial because it is cheaper and lighter.  

ii) Insulation – The Safety Shield

Well, the outermost part of the insulation layer surrounds the conductor, protecting it from short-circuiting wires and any external wire parts. This layer is made from XLPE (cross-linked polyethene), which can withstand deterioration as well as heat.

iii) Bedding – The Inner Cushion

The next component is bedding. It is a soft, smooth portion that adds safety covers to protective coatings. However, Bedding gives steel wires smooth surfaces to rest on, preventing inner damage and additionally enhancing safety shielding needs.

iv) Steel Wire Armour – The Strength Layer

Another important component of SWA is Steel wire Armour.  As its name suggests, the steel wire armouring gives both strength and protection to the cable. The SWA protects cables from crushing, pulling, and other heavy physical damage/swipes.   This is why these types of cables are best suitable for underground or industrial applications.

v) Outer Sheath – The Final Cover

Lastly, the outer sheath encloses every component together. It is made of PVC, which protects the cable against moisture, sunlight and rough usage. It preserves the cable’s strength and safety through time.

3) Main Benefits of SWA Cable

Well, if you need a strong, safe, and durable cable, Steel Wire Armoured (SWA) cable is an excellent option for you. SWA cables prove to be practically useful in demanding environments. Let’s look at the  main benefits of SWA cable:

+ Excellent Mechanical Protection: One of the biggest benefits of steel-wire armoured cable is its built-in strength. You know the armour layer made from steel wire, which offers protection from crushing, pulling and cutting damage.

+ Best for Harsh Conditions: Most importantly, it is designed to bear harsh conditions. Furthermore, SWA cables are resistant to moisture as well as pressure and even UV rays from the sun.

+ Safe and Secure Power Delivery: Another important benefit is that SWA cables provide excellent electrical safety. There are fewer chances of accidental contact, fires, and  short circuits.

+ Easy to Install and Maintain: Unlike other cable types, SWA cables can be easily installed in the open air, underground or on cable trays. Their stiff design means less twisting or tangling during installation, making the entire process easier.

+ Cost-Effective Over Time: In contrast to other cables, SWA cables have high starting cost but offer long-term value. They are durable, so they offer fewer replacements, less downtime and lower maintenance costs.

4) Common Applications

Alright! Apart from being durable, Steel Wire Armoured (SWA) Cables offer great versatility. Now, let’s talk about most common applications of SWA cables!

• Underground Power Supply

Most importantly, SWA cables are best suited for underground installations. Their robust armouring makes them withstand pressure. Whether it’s powering outdoor lights or a garden shed, this cable works perfectly.

• Power Systems

Significantly, SWA cables are frequently utilised in factories and plants to provide power to machines, tools, and systems. In addition, they are best in areas that have heavy vibration, movement, and even heavy foot traffic because of their strong construction.

• Outdoor and Harsh Environments

Well, SWA cables are built to bear harsh weather like rain, heat, cold, and sunlight. Well, that makes them best for outdoor lighting and CCTV systems as well as electric gates. Moreover, SWA cables can be installed on walls and fences or even buried underground; they will continue to work reliably.

• Commercial Buildings

In hospitals, public transport buildings, and other places, SWA Cables are used for power distribution and lighting. They offer good protection and lessen the chances of overheating whilst being easy to maintain. Ok, it makes them suitable for high traffic places.

• Remote and Temporary Installations

As you may have noted, SWA cables are often used in construction areas and temporary event setups. Because of its simplistic, remote and temporary installations, it is ideal for harsh situations.

5) SWA vs Other Armoured Cable Types

Alright! When selecting an armoured cable, you have a variety of options. Now, let’s analyse other armoured cables in comparison with SWA so that you can make a wise decision.

SWA vs AWA (Aluminium Wire Armour)

SWA employs steel wires for mechanical protection. It works well in general, particularly for three-phase and multi-core cables. On the other hand, AWA uses aluminium wires. It is lighter and predominantly used for single-core cables where magnetic interference from steel needs to be avoided.

In dealing with multi-core systems, SWA is generally the go-to choice. In contrast, for single-core cables, AWA reduces overheating caused by induced currents due to heavy magnetic fields.

SWA vs STA (Steel Tape Armour)

Well, in STA cables, steel tape replaces wire. The tape provides safety and is lighter and more flexible. It works well for indoor or fixed installations that have a low chance of damage.

On the other hand, SWA gives greater protective covering and is ideal for above-ground or outdoor use. To be honest, SWA is the best option if protection against impact and strength are most important.

Choosing Armour for Multi-core vs Single-core

Here’s a simple guideline:

For multi-core cables, there is no risk of magnetic interference, so you can use SWA. On the other hand, use AWA for single-core cables; this protects against heat from eddy currents in the steel caused by magnetic fields. Thus, making the right choice here can boost functionality while improving safety.

EMI ( ELctromagentic Interference) and Cable Heating Considerations

EMI and heating are important issues of concern, especially in high-power systems. EMI can be increased, or the cable may overheat due to using incorrect armour types.  

The use of steel armour in centre cables gives rise to circular currents that generate heat. That is why AWA is used instead. Also, shielding poorly protects from EMI, enabling it to influence nearby devices.

6) Things to Consider When Choosing SWA Cable

To be honest, choosing the appropriate SWA cable is not as simple as it seems. Yes, you have to consider a lot of factors, including project-specific requirements and advanced considerations. Let’s discuss the key points to consider when choosing SWA cable:

a) Cable Size and Load

First, you should assess whether the cable can support the amount of power you want to supply. This is called the current load. You know that too small a cable would overheat or fail, while oversizing would simply mean unnecessary expenditure.

A cable size calculator or professional assistance will help choose the right size.

b) Single Core vs Multi-Core

Always remember, it is important to know if you need a single-core or multi-core cable. A single core can be found in some high-voltage configurations, as they are more common than multi-core cables, which are used in homes and commercial setups.

As noted before, single-core SWA cables must use AWA wiring to prevent overheating issues.

c) Installation Environment

Where do you intend to install the cable? Is it placed on a surface that is wet or dusty? Although SWA cables are relatively durable, their environment will still have an impact on their longevity.

If the installation site is rough and requires additional protective measures, then a harsher environment and foot or vehicular traffic will demand even more protection.

d) Earthing and Grounding

Whatever happens, safety must come first! SWA cables will commonly utilise the steel wire as a ground conductor, but this requires proper installation. You should always ensure that grounding complies with regulations to minimise shock hazards or equipment failure.

e) Certification 

Once more, make sure the cable is certified for use in your application’s industry. It is important if it is intended for risky areas.

7) SWA Cable in Explosion-Proof Systems

Alright! Safety is everything in high-risk locations, for example, gas stations, oil refineries, and chemical plants. That’s why choosing the right cable is important. In explosion-proof systems, Steel Wire Armoured cable is often one of the top choices.

Why SWA Cable Is a Smart Choice

SWA cable’s construction allows it to bear physical damage, which makes it well-suited for explosive environments. In such locations, even the tiniest spark or wire malfunction can be dangerous. Hence, the steel armour enhances the shielding and further resists failure due to crushing forces or impacts.

Moreover, SWA cables are easier to properly ground. Well, it helps in controlling electrical abnormalities. This is important when there are risks of flammable gases or vapours since it reduces the chances of ignition from short circuits.

Wiring Precautions You Should Know

When SWA cable is used in explosion-proof equipment, some important measures need to be followed:

• Grounding the Armour: Most importantly, the outer layer, composed of steel wires, should be earthed as this guarantees that there are no leakage currents can ignite stray sparks. So, current drains safely into the ground.

• Explosion-Proof Terminals: Hazardous areas require the use of special explosion-proof Terminals, which are appropriately rated. Such terminals prevent gas or dust from entering equipment and also seal the cable ends tightly.

• No Sharp Bends: It is important to avoid partial or sharp bends on the cable. It can compromise the armouring or damage the insulation, increasing the chances of malfunction.

Using SWA with ATEX or IECEx Equipment

Alright! When working in an explosion-proof area, the entire system—including the cable—must comply with safety regulations. Hence, SWA cables are appropriate for use with equipment certified under ATEX or IECEx, provided they are properly installed.

Always check out that the cables and their fittings match the classification zone’s rating. When in doubt, seeking advice from the manufacturer’s representatives or safety professionals is wisest.

8) Conclusion

Alright! Steel Wire Armoured (SWA) cables are best for normal everyday use as well as for explosion-proof zones, providing safety and strength. So, if you know their functionally and structural composition, it will help you make wise decisions on your projects.

If you’re sourcing reliable explosion-proof electrical solutions, Hexlon offers a comprehensive range of products including explosion-proof distribution boxes, junction boxes, and lighting fixtures — all engineered for hazardous zones and compliant with international safety standards. Our products are trusted by professionals across industries like oil & gas, chemical processing, and heavy manufacturing.

Contact us today to get expert support and high-performance Ex-proof products tailored to your project needs.