They also intend to insure that the installation of foc is done in accordance with telecommunication standards. The circuit installation also includes grounding boxes, screen earthing connection boxesand the related earthing and bonding cables. Departures from this specification shall be fully documented in the tender. Cables installed into conduits or trays have installation parameters such as maximum pulling tensions, sidewall pressure, clearance, and jamming, which must be considered. Single phase underground service meter installation figure 9. Thus, some mvu cables are more susceptible to the effects of voltage surges, such as lightning, that can lead to failure. With more than 14,000 km of cables, 30,000 terminations and 18,000 joints installed and commissioned since 1962, general cables silec underground cabling solutions are your best partner for the life of the entire cable system. Cables may be ordered from the factory with pulling eyes already installed. For constructing transmission lines of the same distance at the identical voltage level, underground lines cost roughly 4 to 14 times more than overhead lines 1. Cables installed in ground shall be laid in a single, horizontal layer spaced 450mm apart. Construction of underground cables studyelectrical.
For underground cables less than 345 kv, the connection from overhead to underground lines require the construction of a transition structure, also known as a riser. Use um master specification 260543, underground services for electrical systems as basis for design and specifying underground electrical and telecommunication pathway systems. Thermal performance of 69 kv underground cables by tong. This tests underground cables using lowenergy signals that do not cause insulation damage, making it possible to locate a faulty section. This practice covers the basic guidelines for installation of fiberoptic cable in underground cable. All dielectric self supporting adss fiber optic cable. Environmental aspects of hvdc underground cables trench width in directly buried cables hvdc underground cables are typically installed in a circuit comprising 2 cables bipole installation. Ieee guide for the design and installation of cable systems in power generating stations ansiieee std 4221986 revision of ieee std 4221 977 published by the institute of electrical and electronics engineers, inc 345 east 47th street, new york, ny 10017, usa april 4, 1986 sh10447 withdrawn.
Undergrounding is the replacement of overhead cables providing electrical power or telecommunications, with underground cables. O digging operation is separate from cable placement. The installation company responsible for laying the cables must heed the following parameters. The major disadvantages associated with using underground power cables are the added cost of installation, increased environmental disruption and increased repair time due to underground cable failure. The minimum bend radius of each cable is relative to the cables diameter.
When installing a high voltage electrical underground cable, a temporary working strip is normally fenced off to permit the construction of the underground cable. Apart armouring of single core cables is provided by round aluminium wires, multicore cables will have galvanized round steel wires. These cables are of course, constructed accordingly. Specification for installation of underground conduit systems. Installation of high voltage underground cables national grid. Underground cable installation manual western power underground cables on western powers distribution system the specifications, procedures,practices and instructions contained in theucim detail the technical requirements to be followed by service providers. Technical specification for underground power cables and. Mvu cables that experience prolonged, wet conditions may have degraded insulation, based upon the insulation material. The selection, handling and installation of electric power cables of rating not exceeding 33kv part 9. Land issues underground cables and overhead lines have significantly different footprints through the countryside when completed. Figures 5 and 6 depict sample transition structure designs. Tdr results are displayed as a graph, and properly functioning cables send back a return signal in a known timeframe based on.
Introduction optical fiber cables for telecommunication application have been installed in pipesducts for many years. An underground cable essentially consists of one or more conductors covered with suitable insulation and surrounded by a protecting cover. For long distance power transmission, the charging current. Ns specification for laying underground cables up to and including 11kv amendment no 3. For higher voltages, 3 cored constructions become too bulky, and hence, even with some limitations we employ single cored cables. Underground cables are usually employed to deliver 3 phase power. Cable installation manual for power and general cable. Industry best practices for radiating cable installation in. This tension is then locked in by the latersetting grout cartridges and the resulting installation is a fully tensioned, fully grouted rockbolt. Ei 020019 installation of underground cables lv to 2kv. It demonstrates the higher technology in developed countries for fire prevention and to make the power lines less susceptible to outages during. Any underground cables which are damaged during installation should be immediately repaired with equal quality material.
Installation of underground cables lv to 2kv document number. Installation of cables in ducts is a common practice today, for both telecommunications and energy transport, ranging from single optical fibres to energy cables of over 100 mm diameter, and a. Epub underground power cable distribution cable overhead. Keywords manholes, winches, sheaves, jetting method. This document refers to other horizon power documents to provide reference standards for underground cable installation work. Cable shall be installed between 750mm and 1200mm cover section 14. The tenderer is also required to offer a recommendation for the two voltage classes of cable. Method statement for installation of high voltage hv. Ieee guide for the design and installation of cable systems. The installation process is influenced by local conditions, local climate, customers.
Installation of cables 4 introduction electric power can be transmitted or distributed by two systems overhead power line or underground cable system. Typically, an underground cable has either one, three or four cores. Diagnostic testing of underground cable systems cable diagnostic focused initiative doe award no. Lines is more, so the voltage regulation is better in case of underground cables low voltage drop. Underground cables are, of course, meant to be installed or laid under the ground.
Ieee guide for the design and installation of cable. Ausgrid maintains a copy of this and other network standards together with updates and amendments on. Obtain consultants approval before cables are covered and trenches backfilled. The extra cost of underground installation includes the higher cost of the. Installation procedure for hv cables in tray the total cable route shall be inspected to ensure that the routing is complete, as per approved layout and it is coordinated with other services. These limits should not be used for cables subjected to pulling tensions during installation. The range of recommended installation temperatures of cables is much smaller than the operating temperature ranges. Specification for installation of underground conduit systems revision date. Diagnostic testing of underground cable systems cable. O possibility of damaging underground cables or other utilities. Underground network installation is more expensive than oh lines, since the cost of cables include cable charges along with road restoration charges which make the per unit coat of ug cabling system several times greater than overhead system. Installation of high voltage underground cables april 2018ver2mh the width of the working strip is dependent upon the the voltage of the underground cable, the number of cables and how many trenches are required.
Electrical power cables may be installed as permanent wiring within. There are three main methods of laying underground cables, which are i direct laying, ii drawin system and iii. Underground cables can help power projects to transmit power past sensitive areas of human habitation and address the concerns of stakeholders. Nsp002 policy for the installation of distribution power. Xlpe cable has become the national standard for underground electric transmission lines less than 200 kv. The connection of the hvdc underground cable to the hvdc overhead line can be placed in a small transition yard. When installing a high voltage electrical underground cable, a temporary working strip is normally fenced off to permit the construction of the underground cable safely and efficiently. When cables are installed in a raceway, underground electrical duct or cable tray. The tests specified within this procedure are the mandatory minimum requirements. This guide is generic yet contains sufficient specific information applicable for most installations of adss cable. All horizon power workers engaged in installing underground cables. Each cable trench is a metre across and over a metre deep fillin must be well compacted to aid the removal of heat concrete cable covers prevent accidental damage to cables and electrocution cementbound sand the conductor is. This part of the specification deals with the material requirements, installation, testing and commissioning of medium and low voltage underground cables in. Armor mechanical damage during installation and operation.
Why underground power cable installations need soil thermal. The installations and maintenance of underground cables are far more expensive than overhead lines. Rockbolts and cables 6 30 minutes, the bolt can be tensioned within two or three minutes of installation after the fast anchor resin has set. Laying uf underground feeder cable directly into the ground. The company is an indirect, whollyowned subsidiary of fortis inc. The proposed cable will be installed in a steel pipe, which provides protection from accidental digins. Direct in the ground in trenches underground cables. The method enables the installation of continuous sections of power cables in one step into a duct up to 3. Undergrounding high voltage electricity transmission. Installation of an underground transmission cable generally involves the following sequence of. Pdf new technique to install power cables into ducts. Power cables are mainly used in distribution networks of power utilities, in industries, in mines etc. Clarified cable sealing, exposed cables and terminated cables requirements, section 14. In addition to the issues discussed above, there are several sitespecific issues that need to be taken into account when designing and implementing underground power cable installations.
Single mobile home underground service pressure treated post figure 9a. Classification based upon number of conductors in the cable. Power cable installation guide cables installed into conduits or trays have installation parameters such as maximum pulling tensions, sidewall pressure, clearance, and jamming, which must be considered. Cables incorporating an armour layer have an extruded bedding of polyvinyl chloride pvc or zero halogen material lszh. Section two covers all topics for correctly installing kerite cable, from selecting conduit and duct sizes, pulling tensions, minimum bending radius, proper cable support and field testing the installed cable. Temperature range the temperature range of the cable is of great importance for both the. Undergrounding high voltage electricity transmission lines. The solid dielectric material replaces the pressurized liquid or gas of the pipetype cables. When editing the specification, turn on hidden text and follow the spec editor notes. The selection, handling and installation of electric power cables of rating not. Underground commercial distribution ucd installation and. Assessment of 69 kv underground cable thermal ratings. It may be increased at certain points, for example road, rail, river and canal crossings, to accommodate the more.
The crosslinked polyethylene xlpe underground transmission line is often called solid dielectic cable. These guidelines on fiber optic cables underground installation aim at avoiding any damage to existing underground infrastructure such as existing foc, sewage or water pipes, electrical cables or other telecommunications cables. These include tradeoff analysis between depth of installation, cost of installation, and thermal stabilization. Welcome to the ninth edition of general cables cable installation manual for power and control cables. For issue to all ausgrid and accredited service providers staff involved with the design and installation of underground cables and conduits, and is for reference by field, technical and engineering staff. Some of the important parameters that need special attention during cable pulling installation are. An introduction to high voltage direct current hvdc. Premise cables these cables are designed to handle the stresses of indoor applications. Transmission cables are often 35in 75125mm in diameter and may be installed directly buried or in, typically, 68in 152203mm plastic conduits with commercial installations up to 500kv. Installation guide for optical fibre cable edition 05. Ns specification for laying undgerground cable up to. Although several types of underground cables are available, the type of cable to be used will depend upon the working voltage and service requirements in general, an underground cable must fulfill the following necessary requirements. The reliability of underground cable network highly depends upon proper laying of cables, quality of cable joints and branch connections etc.
All cables shall be installed with approved identification bands at each end and over their entire length at 30mtr intervals. Standardisedcable installation depth to minimum cover of750 mm and maximum depth of 1500mm, section 14. Increased care during installation and the use of modern cable insulation have resolved the historic. Single mobile home underground service alternate meter pedestal figure 10. All parties installing new underground distribution power cables and auxiliary cables for connection to the ompany s network shall follow the content of this document.
The width of this temporary working area is invariably more than the width of the easement strip required by national grid, and may not necessarily be centred on the underground cable. Section two cable installation the cables ultimate life is optimized by taking proper care during installation. Size and length of the cables to be checked by the engineer in charge and supervisor before cutting the hv cables. This is known as direct burial, and if you do this, the uf cable must be at least 24 inches below the surface of the ground, to minimize the chance of the cable being pierced by routine shoveling. Most extruded cables are ac, but a very few are dc. While underground cables are more reliable than overhead, fault locating and repair can be much more difficult and costly than that of an. Cabling for centralized fiber architecture and olans. Fiber optic cable is also placed underwater across rivers or lakes. Underground network installation is more expensive than oh lines, since the cost of cables include cable charges along with road restoration charges which. During the delivery of the optical cable the offloading.
Industry best practices for radiating cable installation in tunnels in order to identify optimum locations for radiating cables, one must have an understanding of specific requirements for the network and how the radiating cable location impacts signal coverage. Other installations, such as buried and aerial, have different installation parameters. Placing cables underground has the added benefits of reducing transmission losses, aiding planning consent and reduced risk of service supply loss through extreme weather. The purpose of undertaking underground cable testing is to prove cable integrity after installation and jointing work is completed and before connection to the essential energy network. Underground installation of optic fiber cable placing.
Fiber optic cable, underground installation, cable pulling. All optical fiber cables are sensitive to damage during shipping, handling, and installation. The cable should never be bent below its minimum bending radius. Current transformer cabinets, overhead or underground service, window type cts figure 11. An introduction to underground cable installation placing cables underground has traditionally been seen as a more costly solution than an overhead alternative, however lower cost production methods such as xlpe over lead or oil filled cables, improved technologies and installation methods and increased reliability means the cost differential.
Edit the specification and details to make them project specific. Underground cable installation manual western power. Medium voltage underground cables 8 round the conductor it is necessar to provide insulation to prevent electrical short circuits in ediu voltage cables there are two main types of insulation material. It is an assembly of one or more individually insulated electrical conductors, usually held together with an overall sheath. This policy shall be used as the primary source of information for the installation of distribution power cables. In the following paper, we would like to suggest some of these areas for your consideration in. Installation of underground submarine electric cables.
Insulating underground cables a typical cable installation method cables are laid in a trench in groups of three. Method statement for installation of high voltage hv cables. It covers 600 volts through 46 kv insulated copper conductors, however, the cable installation manual is not. Power cable installation guide figure f5 multiple sheaves figure f6 sheave arrangements for feeding into cable tray training radius the training radius is the final positioning of cable ends after the cable has been placed in the raceway. Backbone passive distribution network equipment figure 1. Ppt underground cables powerpoint presentation free to. A guideline for laying of cables and installation of sleeves.
Ieee guide for the design and installation of cable systems in power generating stations ansiieee std 4221986 revision of ieee std 4221 977 published by the institute of electrical and electronics engineers, inc 345 east 47th street, new york, ny 10017, usa. To select the cable it is necessary to consider whether the specific system and installation conditions and requirements can be. Beyond that, insulation required for the cable is too much. Further, the vertical runs where the cable descends into the ground at the house side.
For same reasons, only lszhfr cables can be installed inside premises. Uo kv phasetoground voltage, u 225 kv rated phasetophase voltage, um 245 kv highest permissible voltage of the grid high voltage underground cables 6. The proposed cable will be installed in a steel pipe, which provides protection from accidental dig. Optical fiber cables are designed with a minimum bending radius. This manual provides installation information for power and control cables for industrial. The minimum bend radius of each cable is relative to the cable s diameter. Power cables are used for power transmission and distribution purpose. Commscope cables meet or exceed all telcordia gr409core and ansiicea 696 requirements, as well as gr20core requirements for crush resistance, impact resistance, flexing and twistbend. The other utilities must maintain clearances as outlined in the nesc or by mutual agreement. Further, the vertical runs where the cable descends into the ground at the house side and emerges up from the ground at the outbuilding.
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