What is the correct armoured cable for your installation?
Finding the right low voltage (LV) armoured cable for your installation need not be a hassle. In this blog, we’ll explore the role of armoured cable and discuss how you can make the right choice for your project.
Electric circuits that may be at risk of physical damage should be protected. Armoured cables provide the ideal and efficient solution that is suitable for indoor and outdoor applications.
Armoured cable explained
As the name suggests, armoured cables act as bodyguards for electrical circuits. An armoured cable, also known as steel wire armoured (SWA) cable, or booklet armoured cable, is a low voltage (LV) power cable or control cable that is designed for use in mains supply at maximum 600/1000 V.
Indoor armoured cables can be used in places such as plantrooms, where cables may be susceptible to damage from heavy machinery. Outdoor armoured cables also need to withstand temperatures, harsh weather conditions, mechanical stresses, and third-party damage.
Prysmian LV armoured cables: BS 5467 and BS 6724
Prysmian manufactures the two most common types of low voltage armoured cable: Prysmian BS 5467 and Prysmian BS 6724. Both cables are made in our UK factories, so you can be sure of a high quality, dependable solution.
Prysmian's XLPE insulated, PVC sheathed SWA and AWA cables are manufactured in accordance with BS 5467.
Single core cables feature aluminium wire armour (AWA). This is because single core energised conductors produce an alternating magnetic field inducing a small current in the steel wires causing heating. Aluminium is non-magnetic and remains unaffected.
Multi-core armoured cables feature galvanised steel wire armour (SWA). Current would be induced in the steel wires, however this effect is cancelled out in multi core cables. Therefore, induction heating is eliminated in these cables.
Although steel wires can prevent physical damage to the inner cores, a zinc coating is applied to protect them from exposure to air, water, or moisture to reduce rusting. Rust (iron oxides) not only makes the wires physically weak, but it does not conduct electricity. If the armour wires are designed to play an electrical role in the circuit, then the rust can increase the risk of circuit failure and may even cause a fire. It is very important to note that the zinc coating must be applied consistently onto each of the armour wires to ensure longevity and to ensure a safe and reliable circuit.
Prysmian BS 5467 is suitable for industrial wiring and mains distribution. The cable features aluminium wire armour for the single core and a steel wire armour for all multi cores. BS 5467 is particularly robust and makes it well suited to areas at risk of mechanical damage.
Prysmian BS 5467 has a PVC sheath and XLPE insulation. XLPE is a thermoset material, which has a maximum working temperature of 90°C. This allows the cable to run a high current through its conductors. The molecules of XLPE are chemically bonded together, which gives the insulation greater ductile strength and impact resistance.
Prysmian BS 6724 is a Low Smoke Zero Halogen (LSOH) armoured cable designed for the interconnections of systems as control cables or as power cables. BS 6724 can directly replace standard PVC sheathed BS 5467 armoured cables for applications where low smoke, zero halogen performance and reduced flame propagation is required.
When exposed to fire, PVC cables will produce dense black smoke, toxic fumes and acid gas. As a result, LSOH cables are often specified for indoor public areas including hospitals, shops, train stations and airport terminals.
Similarly, to other cables, armoured cables can be installed in a range of different methods including in air, surface, tray/basket or in ducts, and each method affects the CableApp rating. The added method is direct burial installation. Armoured cables have built-in protection, so they can be installed directly into a trench without further physical protection.
Making the right choice with CableApp
Of course, identifying the right size armoured cable to use on your project is just as important. This is where CableApp comes in. CableApp is the efficient, easy-to-use cable calculator designed to help electrical professionals to choose the right cable for any job. CableApp works by offering two calculation methods: cable type and cable calculator. Cable type allows you to choose the product family, voltage etc, and cable calculator allows you to select the installation parameters. Whether you’re looking for LSOH, armoured or fire performance cables, CableApp can help you find the best solutions for the job.
The Prysmian Extended Warranty
Armoured cables BS 5467 and BS 6724 are included in the Prysmian Extended Warranty. We take immense pride in the quality and reliability of our electrical products and understand that when it comes to your electrical installations, peace of mind is paramount. To demonstrate this further, we have introduced the Prysmian Extended Warranty – a ten-year warranty when you purchase and install Prysmian SWA cable and Bicon glands or cleats. With the Prysmian Extended Warranty, you can be assured that your investment in our products is safeguarded for a decade.
Visit our webpage for full terms and conditions: https://uk-stage.prysmian.com/markets/trade-and-installers/power-cables/extended-warranty
Power cables that deliver
We are the experts in power cables. Our range of power cables enable a wide range of applications, including indoor and outdoor LV installations, such as lighting systems and other building services systems. Find out how Prysmian Group can power your projects.