Of all the decisions you will be making when designing an electrical installation, choosing cables is likely going to be the most critical. There are just so many variables to consider when selecting cable—voltage, current, conditions, safety, etc., and one of the easiest is application or non-application of armoured cable. Your choice will make or break the safety, expense, life, and overall reliability of your project.
Here, we will explain the different armoured and unarmoured cable specifications by the SWA Cable Manufacturers, their benefits and drawbacks, and assist you in deciding what is best for your project.
Learning the Basics
Let us begin by explaining the basics by asking the SWA Cable Suppliers exactly what these terms mean.
Armoured Cable: It consists of a cable that is wrapped in protective metal armour, either in the form of tape or steel wire, over conductors inside. Armoring provides mechanical protection, particularly under harsh environments or where cables are to be exposed to potential external abrasion or pressure.
Unarmoured Cable: The term tells us that there is no metal covering shield. The cables contain the core conductor alone, insulation, and, if wished, environmental protection in a sheath. The cables are lighter than armoured cable but more flexible and less vulnerable to mechanical protection.
Main Differences Between Armoured and Unarmoured Cable
- Mechanical Protection
The most apparent difference is mechanical robustness. Armoured cables resist physical abuse, i.e., crushing, hitting, or being gnawed by wild animals. This makes them appropriate for outdoor or below-ground applications where heavy equipment, ground settlement, or wild beasts would be a concern.
Unarmoured cables, even though normally well-insulated, are not intended to withstand much physical pressure. They are usually laid in buildings or in protected conduit where they can be preserved from mechanical pressure.
- Installation Environment
Armoured cables are used where tough or hostile conditions exist—factory, building, underground, or exposed outdoors. Their sturdy make ensures that installed underground or suspended in the surroundings, they remain electrically continuous and intact.
Unarmoured cables, however, are employed in a range of applications where mechanical abuse is rare or nonexistent—such as within ceilings, walls, or encased cable trays. They should be employed where cabling will be in interior domestic spaces or for inner use inside shielded compartments.
- Cost Factors
Expenses would always be included in any blueprint. Armoured cables are pricier compared to unarmoured cables as they entail additional material (armour of steel) and processing. Armoured cables are heavier and harder to handle, and that is an additional labour expense for the installation.
Unarmoured cable is less expensive to buy and install and therefore more economical for small or highly protected installations. But the initial economic benefit must be balanced against the risk and cost of replacement in the event of the cutting of the cable in service.
- Weight and Flexibility
Presence of a steel sheath in armoured cable causes the cable to be considerably heavier and more rigid compared to unarmoured cable. It is therefore more inconvenient to handle, bend, or route through narrow conduits.
Flexible unarmored cable is easy to handle and therefore appropriate for use in cases where routing in intricate routes or through narrow channels is present.
- Electrical Safety
Both both in electrical as well as in voltage and current ratings offered, both these cables are double insulated, and both are available in similar ratings. But also, the metal sheath of armoured cable can itself be utilized as a conductor to earth in certain circuits in order to direct the fault currents rapidly towards earth for the purpose of an additional feature of protection.
All that being said, there simply must still be proper grounding and earthing systems no matter what cable is used.
When to Apply Armoured Cable?
You should definitely use armoured cable under any of the following conditions:
- Subterranean Installations: Cables that are laid directly in the earth or in trenches are advantaged by the additional protection from pressure and moving material that armour offers.
- External Installations: Armoured cables are stronger and more resistant since they will endure the power of weathering, temperature or exposure to UV radiation.
- Industrial applications: Equipment or factory conditions that physically destroy a cable are the standard in factories, plants, and building sites. Armoured cables would suit such environments.
- High-risk areas: Wherever the cables are likely to be exposed to rodents, equipment, or physical abuse, armoured varieties must be employed for ruggedness and protection.
When to use Unarmoured Cable?
Unarmoured cable can be utilized in:
- Domestic Wiring: Inside walls, ceilings, and ducts where the cable is not exposed to pressure or impact.
- Control Panels and Equipment: Inside control cabinets or equipment where the environment is sealed and dry.
- Temporary Installations: Temporary installation or work that will never be subjected to mechanical stress.
- Cost-Conscious Projects: Where there is little risk of damage and cost is of most concern.
However, as an acceptable practice problem, unarmored cables can be pushed into cover conduits or trunking systems to provide greater mechanical protection.
Long-Term Durability and Maintenance
Longevity is normally a long-term factor that is not quite worth the expense until issues occur. Armoured cables, being pricier up front, will be more robust in extreme conditions and need to be replaced less often. Their longevity means there is less disturbance, repair, or safety hazard during the project.
Unarmoured cables would similarly require more severe planning and guarding when installed to be long-lasting. Incorrectly installed, they are prone to damage that will lead to electrical failure, danger, or costly downtime.
Conclusion: Which Is Suitable for Your Project?
Be it armoured or unarmoured cable, it’s about understanding requirements for your own specific project. If the cable has to withstand stresses from physical, weather, or variable conditions, then the safer, heavier-duty alternative, though more expensive, is armoured cable. It is an investment worth making in the ultimate reliability and integrity of your electrical system.
On the other hand, though, if your installation is indoors, very well shielded, and inexpensive, unarmored cable is adequate for you—especially if it is fitted with protective conduits or other protection. In brief:
- Use armoured cable for external, buried, hazardous, or heavy-duty applications.
- Use unarmored cable for safe, internal, or low-risk installation.
- Every task is different, and the right cable to fit makes a difference to safety, working, and cost.
Uncertain, you may have to refer to an electrical engineer or approved installer to make your best-informed choice for your job needs.
Know More: Flexible Electrical Wire: Top Benefits & Features of Flexible Cables
