Keystone Academy

Whether getting a LAN cable for home use or selecting a LAN cable while planning for industrial needs or business network infrastructure, you may have questions about which cable to use. You may notice several types to choose from, namely Cat 5, Cat 5e, Cat 6, Cat 6A, Cat 7, Cat 7A, and up to the latest Cat 8. The Cat ratings stand for the category, and the different numbers represent different speeds and specifications for each cable type. The higher the number, the newer the technology and the higher the data rate supported. The basic differences to look for across the categories would be : Maximum data rate (measured in megabits per second, Mbps or gigabits per second; Gbps) Bandwidth (measured in megahertz; MHz) Shielding (to protect against interference) To generalize, Cat 5 is mostly obsolete now as it only goes up to 100Mbps.  Cat 5e is suitable for installation in residences and small offices with network speeds below 1Gbps. It supports bandwidths from 100 MHz up to 350 MHz. An easy way to think of bandwidths would be similar to traffic flow; the wider the road or higher the bandwidth, the more cars or data can pass through at a go. In Cat 5e, the pairs are twisted together tighter than in Cat 5 to reduce crosstalk (the interference caused by electromagnetic signals affecting another electronic signal). Cat 6 is recommended for larger installations like University campuses and big office buildings. Cat 6 can support 1Gbps up to 100 meters and 10Gbps up to 55 meters. It supports bandwidths up to 500 MHz. The pairs are twisted even tighter than Cat 5e to help with crosstalk. Keystone Cable’s Cat 6 also has a spline between the pairs to minimize crosstalk. Cat 6 can be shielded to improve performance (earlier network cables were all unshielded). For example, an unshielded twisted pair cable would be satisfactory for a short run between a computer and router, but a foil-shielded cable is better for longer runs or where the cable would pass through areas of high electrical noise, such as in an industrial factory. At Keystone, our Cat 6 stock include U/UTP and F/UTP. Cat 6A is suitable for industrial, commercial, and data centre applications. Cat 6A handles 10Gbps up to 100 meters and supports up to 500 MHz bandwidth. The pairs are twisted tighter than Cat 6 to help with crosstalk and allow higher bandwidth. It is common to find each pair individually foil-shielded and with an overall braided shield. At Keystone, our Cat 6A stock include F/FTP and F/UTP. Cat 7 and Cat 7A are commonly found in bandwidth-intensive applications like data centres or other places where extra interference protection is needed. Cat 7 and Cat 7A handle 10Gbps up to 100 meters and support bandwidth up to 600 MHz. What helps this cable category perform better than the previous ones are more strict and precise manufacturing processes to increase the tightness of the twists, the individual shield and the overall shield to reduce crosstalk and interference dramatically. Cat 7 and Cat 7A have shown in test results to deliver 40 Gbps over distances up to 50 meters and 100 Gbps up to 15 meters. The one drawback of using Cat 7 or 7A may be that it is not recognized by EIA/TIA (wiring standards for commercial and telecommunications wiring) and uses its proprietary non-RJ45 connector, which may be more challenging to purchase. At Keystone, our Cat 7 stock includes S/FTP. Cat 8 is new and explored for use between servers and switches in large data centres with an insanely high bandwidth requirement. It is uncommon to use Cat 8, although it does jump several iterations in performance. It can handle 25Gbps/ 40Gbps up to 30 meters and supports bandwidth up to 2000 MHz. The development of Cat 8 is subdivided into Cat 8.1 and Cat 8.2 under IEC standards. Cat 8.1 is backwards compatible with Cat 6A, Cat 6 and Cat 5e, while Cat 8.2 is backwards compatible with Cat 7 and Cat 7A. This is due to the connector relationship where Cat. 8.1 uses a standard RJ45 while Cat 8.2 uses a non-RJ45 connector. As a rule of thumb, your network is only as fast as the slowest part of your entire channel. For example, if your internet connection is 300 Mbps but your router’s ports can transfer only 100 Mbps, then your whole network would be limited to 100 Mbps instead of 300 Mbps. Hence when you consider the Cat type, you may scrutinize the rest of your system to ensure compatibility. However, we recommend future-proofing, especially if you intend the cable installation to be concealed within walls. In such cases, we recommend getting a LAN cable one step higher than your current requirements to future-proof your installation. For more enquiries, please check in with our sales team. Contact Sales

What is the difference between unarmoured and armoured cables? As the name implies, an armoured cable has added protective armour that helps protect the cable core. This is important in places where there could be accidental damage to the cable due to mechanical stress or impact. To put it in context, typically, armoured cables would be used when you require the cable to be buried directly underground for outdoor installation or in tunnels. There may be instances where the ground is opened up again, and in the process, a spade or mechanical excavator may hit the buried cable by accident. In this case, the armour would help protect the cable conductor core from being exposed easily and prevent electric shocks and interruptions in power delivery. You may come across aluminium wire armour (AWA) or steel wire armour (SWA) for standard power cables. Steel is naturally a stronger material, but you will notice that single-core cables are ALWAYS paired with AWA and never SWA. This is because aluminium is non-magnetic. What is AWA vs SWA for armoured cables? If a single-core cable is paired with steel wire armour, a magnetic field will be induced when current flows through – the whole cable becomes a giant magnet. The higher the current, the larger the field. The magnetic field will induce an electric current (eddy current) in the steel, which would cause overheating and massive derating of the cable. Aluminium, due to its non-magnetic nature, would not cause this issue. However, once we move past single-core into two or more cores, it is safe to revert to galvanized steel wire armour because magnetic fields produced in such multi-core cables will have a cancelling out effect by the other cores’ fields thereby preventing the magnetic flux. Armoured cable construction This would be a typical armoured cable construction at Keystone: Conductor Class 2 stranded plain annealed copper Insulation Cross-linked polyethene (XLPE) is recommended over polyvinyl chloride (PVC) to provide a higher maximum operating temperature, better water resistance and stronger dielectric properties. Bedding A protective layer between the insulation and the armour. Armour Steel or aluminium armour to provide mechanical protection. Sheath  PVC or LSZH (Low Smoke Zero Halogen) outer sheath that holds the cable together. LSZH would be recommended for public areas or in tunnels. At Keystone, we would include UV stabilizers and anti-termite additives in our cable sheath material. Please check in on with our sales team for more information. Contact Sales

Electric cable conductors must be isolated from other conductors and the environment to prevent short circuits. To do so, we extrude a layer of insulation around the conductor. Here, we examine Polyvinyl Chloride (PVC) and Crosslinked Polyethylene (XLPE), the two most common insulation materials used in the cable industry. Why PVC Insulation? PVC is the most widely used insulation material in power cables. This is because PVC insulated cable is:  1) A cost-effective material for electrical and physical protection for standard low-voltage building cables2) Has a small bending radius and is very easy to install in narrow places Applications for PVC cables include general low voltage cabling such as lighting and public building use.However, standard PVC has certain limitations: 1) Standard PVC has a maximum operating temperature of 70°C2) It is not as hardy a material when it comes to resistance to water and environmental stress cracking (ESC) When should you choose XLPE Insulation? XLPE has a maximum operating temperature of 90°C. This means that if we compared an XLPE insulated cable and a PVC insulated cable for the same conductor size, an XLPE insulated cable could carry a higher current load. This also means that based on your current load requirements, there may be instances where you would be able to select a smaller cable size if you used an XLPE insulated instead of a PVC insulated cable. XLPE is a hardier material compared to PVC due to the cross-linking process. XLPE provides greater tensile strength, elongation and impact resistances compared with PVC. This cross-linking process also enhances the material’s resistance to oil and chemicals even at elevated temperature; this makes XLPE a popular pick as insulation for LSZH Flame Retardant or Fire Resistant cables. Applications for XLPE insulated cables are therefore popular as main risers in buildings, LSZH flame retardant and fire resistant cables, as well as beyond low voltage applications such as medium to extra high voltage. The table below shows a simple comparison of the properties of these materials. Speak with our sales if you would like more information on what to choose for your requirements. Contact Sales

LSZH Flame Retardant (FRT) and LSZH Fire Resistant (FR) cable are two distinct types of cable properties, although these terms are often misused. Flame and Fire can be used interchangeably, but confusion occurs between Retardant and Resistant. Knowing what these cable properties mean can help ensure you get the suitable cable for your application. LSZH Flame Retardant (FRT) Cable LSZH FRT cable is a cable that does not promote the spread of fire. But the cable will not maintain circuit integrity in the presence of fire. The international standards on flame propagation are IEC 60332-1-2 for a single insulated wire or cable or IEC 60332-3 for vertically mounted bunched wires or cables under fire conditions.  To ensure safety during a fire, FRT cable typically uses LSZH material. LSZH produces little smoke or acidic gas when burned**, so LSZH FRT cable also undergoes acid gas emission tests to IEC 60754 or BS EN 60754 and smoke emission tests to IEC 61034 or BS EN 61034.  LSZH FRT cable is a vital cable to be used in enclosed areas with high foot traffic, such as underground passenger systems, airports, schools, hotels, hospitals, and high-rise buildings.  LSZH Fire Resistant (FR) Cable LSZH FR cable is a fire safety product, which means it not only reduces the spread of fire, it will maintain circuit integrity in the presence of fire. FR cable has a layer of mica tape around individual copper conductors. Mica is an incombustible natural inorganic mineral with high dielectric strength and excellent heat resistance. Hence during a fire, the mica acts as a fire barrier to the conductor and maintains circuit integrity. In addition to LSZH FRT tests (IEC 60332, IEC 60754, and IEC 61034), LSZH FR cable is also tested to SS 299, SS299-1, BS 6387, IEC 60331. These tests cover the cable’s resistance to fire, resistance to fire with water and resistance to fire with mechanical shock. LSZH FR cable is an important cable to be used when you require critical electrical installations to perform during a fire evacuation: fire alarm systems, voice alarm systems, and emergency lighting systems. At Keystone, we ensure that our LSZH FR cables fulfil BS 6387 Cat. CWZ provides the highest performance and safety levels for such cables. **What is Low Smoke Zero Halogen (LSZH)?  To understand the properties of LSZH, we compare it to the most commonly used cable material, PVC or polyvinyl chloride. In the event of a fire where PVC burns, black carbon smoke and hydrogen chloride gas (HCl) are released. Black smoke impedes general vision. And when gaseous hydrogen chloride comes in contact with moisture, such as a person’s eyes, mouth, throat and nose, it dissolves to form hydrochloric acid, causing extreme irritation and choking, hindering escape. (CH2CHCl)n + O2 → CO2 + CO + HCl + H2O LSZH, because of inorganic additives such as aluminium hydroxide or magnesium hydroxide, releases gaseous water when burned, which helps envelop the flame and exclude oxygen from the fire. In this chemical reaction, the decomposed products are non-toxic and the mineral phases MgO and Al2O3 are alkaline, reducing the likelihood of acidic gas irritations. When burned, LSZH also emits less optically dense smoke, thus allowing better vision and escape.  Mg(OH)2 → MgO + H2O or 2Al(OH)3 → Al2O3 + 3H2O For more information on LSZH cables, please get in touch with our sales team.