Cable basics

  Medium Voltage (MV) are power cables widely used in commercial, industrial, and electrical utility applications. At Keystone, our MV cables have a voltage rating from 6kV to 30kV. In this blog, we will discuss the construction of MV cables and explain how each layer contributes to their overall functionality. Construction of a MV Cable ConductorThere are 2 types of conductors that we use for the construction of our MV cables: Copper and Aluminium. Copper: Made from electrolytic copper with a purity exceeding 99.95%. Aluminium: Drawn from aluminium ingots with a minimum purity of 99.70%. Conductor ScreenOur conductor screen is an extruded cross-linked semi-conducting compound that covers the metallic conductor. This layer acts as a stress point in the insulation, potentially weakening its long-term durability. Insulation ScreenThe insulation screen is a cross-linked semi-conducting compound extruded over the insulation. It provides a smooth surface, serving as a transition material between the insulation where an electric field exists and the conductive metallic screen, where the electric field is zero. Thus, this reduces the stress at the insulation layer. Metallic ScreenThe metallic screen typically consists of a layer of helically applied copper tape with an overlap, over the insulation screen. The metallic screen in a 3-Core cable ensure that the electric field remains contained within the cable core. Cable Assembly (Optional)For 3-Core cables, identification taoes (Brown, Black, Grey) are placed under the metallic screen before the cores are laid up. A non-hygroscopic polypropylene filler is applied between the laid-up cores to provide a circular shape for the overall cable. Polypropylene tape(s) or PETP (Polyester) tape(s) is used as a barrier tape over the laid-up cores. Separation Sheath (Optional)All armoured cables include an extruded layer of Black PVC [1], MDPE [2], or LSZH [3] separation sheath, applied over the core or laid-up cores to prevent corrosion by separating different metals and avoiding galvanic effects. Armour (Optional)In armoured cables, the armour is applied over a separation sheath for additional mechanical protection. Single-core cables use aluminium wires (AWA), double aluminium tape armour (DATA), while multi-core cables use galvanised steel wire armour (SWA), or double galvanised steel tape armour (DSTA). Outer SheathAll cables have an extruded layer of PVC [1], MDPE [2], or LSZH [3] outer sheath over the core, laid-up core, or the armour. This outsheath, usually black, protects the cables from sunlight and termites. Another colour may also be provided upon agreement between the manufacturer and purchaser. [1] Polyvinyl Chloride[2] Medium Density Polyethylene[3] Low Smoke Zero Halogen For more information, check out our Medium Voltage Cables catalogue. Download Catalogue Keystone’s Commitment to Our Clients We are committed to providing exceptional customer satisfaction for our clients through a quality management system. Our experienced and highly skilled inspectors ensure that newly manufactured MV Cables are tested in a clean dust-free room environment and that each cable meets international standards such as IEC 60502-2 and BS 6622. For any enquiries regarding Keystone’s MV Cables, please check in with our sales team. Contact Sales

Optical Fibre Cables (OFCs) are used in many important telecommunication applications to transmit data. These cables are suitable for long-distance applications due to their wide bandwidth. They are also known for having high transmission rates against any form of electromagnetic interference (EMIs).

Power and control cables transmit and distribute electrical energy in various applications. In cases where Electromagnetic Compatibility (EMC) is required, Variable Speed Drive (VSD) cables become an attractive choice. What are VSD Cables? VSD cables are 3-core cables specially designed to limit the effects of Electromagnetic Interference (EMI). They are screened, heavy-duty cables for machinery that requires speed control.  They are used in control and motor systems supply in industrial water pumps, conveyor systems, textile machines, cranes, and paper industries. Symmetrical Design VSD cables are designed symmetrically, where 3 earth conductors are situated in the interstices of the 3 phase conductors. This enables us to achieve a minimal ground current, reducing the chances of bearing fluting and thus preventing motor bearing failure. Keystone Cable’s VSD Cables Our VSD cables have been selected for iconic projects in Singapore and Australia, such as the Jurong Island Desalination Plant in Singapore, Amazon Data Centre in Singapore, and overseas, such as BHP Billiton – Macedon in Australia. We have a strong cable specialist technical team to provide recommendations for your projects. Please contact us should you require more information. Contact Sales

Power cables are ubiquitous for different industrial applications. In cases where ordinary power cables cannot operate under certain harsher conditions, H07RN-F neoprene cables become an attractive choice. What does H07RN-F mean? H – conformity to harmonized standards (set by CENELEC that standardizes electrotechnical specifications)07 – voltage rating is 450/750VR – EPR insulationN – PCP jacketF – Flexible copper conductors H07RN-F neoprene has the following properties that make it a good heavy-duty electrical cable: Flexible In addition to the rubber properties, which give it good flexibility, neoprene cables also use Class 5 copper conductors, which indicate finer copper strands to make up the conductor core. This prevents the cable with high flexibility properties and allows neoprene cables to be installed either as a fixed or mobile cable. Chemical Resistance The cables have great chemical resistance and thus can be installed under adverse conditions such as oily, acidic, and alkaline environments. Scratch Resistance Neoprene has superior resistance to abrasions and scratches. Therefore, they are suitable and commonly used at worksites. Wide Temperature Range Compared to standard PVC insulated cables, which have a temperature rating of 5°C to 70°C, neoprene cables have a larger range of temperature rating of -25°C to 90°C; under high-temperature conditions, the neoprene cable insulation will not melt, and at low-temperature conditions, neoprene cables can still maintain its flexibility and not crack. It is thus a popular choice for use under environmental hazards, including water, sunlight, sand, and snow. Given the distinct advantages of neoprene cables, they are popular for industrial use and use in worksite equipment such as power tools, pumps and generators.  For more information on how EPR insulation may compare with other common cable materials, we have a summarized table for reference. Certified Neoprene Cables Given the heavy-duty use of such cables, selecting a brand where the neoprene cables have been certified is important. Keystone Cable’s neoprene cables are certified by VDE, a German third-party organization in standardization, testing and certifications. Our neoprene cables have been selected for use in iconic projects such as Amazon Data Centre, Singapore MRT, Jurong Port, Sengkang General Hospital, and Singapore F1. We have a strong cable specialist technical team to provide recommendations for your projects. Contact us should you require more information.

In search of a clean and sustainable energy source for the future, solar remains the most promising renewable energy source for Singapore and most Southeast Asian countries. Singapore aims to harness 1.5 gigawatt-peak (GWp) of solar energy by 2025 and will accelerate the country’s goal to at least 2GWp of solar power by 2030. As a result, there is an increasing demand for Solar PV systems: solar modules, inverters, substructures, plugs, fuses, terminal boxes, and solar cables. In response to the rapidly growing demand of the solar industry, at Keystone, we play our part in contributing to renewable energy sources by providing high-quality Keystone photovoltaic cables that meet stringent requirements. A solar cable is used in photovoltaic power generation. Solar cables are designed to be UV- and weather-resistant and can be used within a wide temperature range for indoor and outdoor applications. Solar Cable Construction Keystone solar cables are double-insulated with cross-linked polyolefin (XLPO). Compared to common power cable insulations such as PVC and XLPE, XLPO has a higher nominal temperature rating of -40°C to 120°C. XLPO insulation has excellent UV resistance, flame retardancy, chemical resistance, and durability. In addition, XLPO is halogen-free, meaning it will not emit toxic gases when exposed to fire. Using poor-quality solar cables may reduce the lifespan of entire solar PV installations, whereas high-quality solar cables prevent pre-mature ageing processes when installed under appropriate guidelines. To ensure the quality of the solar cables, Keystone solar cables are manufactured in accordance with EN 50618 (H1Z2Z2-K) and certified by TÜV Rheinland. EN 50618:2014 consists of a series of stringent tests for cables used in PV systems, which include electrical properties test, constructional and dimensional test, insulation and sheathing material test, cold impact and cold bending test, ozone resistance test, weather/UV resistance test on the sheath, dynamic penetration test, damp heat test, shrinkage test, vertical flame propagation and smoke test. The entire testing process is extensive to ensure the quality and reliability of the solar cables. Keystone solar cables are reliable for the entire solar PV system lifespan as they have a service life of more than 25 years under normal use with proper installation. Here are some installation tips we have gathered to ensure a good solar cable lifespan: Avoid using installation bundles with many cables, as this could raise the ambient temperature of the cables and cause derating. Avoid having cables completely exposed to the weather and laid haphazardly or transversely. Avoid laying cables in the rain gutter. Pay attention to clamped points or cables that lean over sharp edges to prevent damage to the sheath or insulation. Do adhere to the minimum cable bending radius. For instance, please do not install the solar cables in a tight loop formation, as it would likely exceed the bending radius. As solar cables are important to the entire PV system, Keystone technical team can help provide professional guidance on choosing the most appropriate solar cables for your installation. Our solar cables have been selected for large solar farms in Singapore, Indonesia and Vietnam, such as Singapore Solar Nova HDB Rooftop solar project(25Mw), JTC Jurong Island Solar Farm in Singapore, Trung Nam Solar Power Plant(200Mw), Tra Vinh Solar Power Plant(95Mw) in Vietnam and Gangga Island Resort and Spa Solar project in Indonesia. To learn more about Keystone’s solar cables, please contact our team. Contact Sales