Audio jacks are found in lots of different audio equipment and musical instruments, that accept external sound sources. This type of cable is used to connect appliances such as lamps or extension cables to the power outlet sockets. Owing to their high quality, our cables have found wide usage in various electronic and electric equipment, where conditions of high temperature persist. Heat shrink cable termination hv 33kv single core xlpe. This article considers why it is important to ensure steel wire armour swa cables are effectively earthed.
In single core armoured cables, you do not have the magnetic fields generated by the other two phases. Method g g single core cables laid flat and spaced in free air this method applies to cables installed on cable. Note that single core cables armoured with steel wire or tape must not be used for a. Cable earthing conductors shall be copper strip with appropriate section laid in formed cable trenches or. Home technical articles ehvhv underground cable sheath earthing part 12 2540. Figure 10 typical 3core 12 kv cable with copper tape earth screens and steel wire armour. What is the best method of earthing such cable, single end or both the end earthing. Multicorecables on racks or trays may be bunched in a maximum of two layers. Because, in multi core cables, the resultant or the residual flux available for linking with the armour would be zero.
Earlier the generators and transformers were of small capacities and hence the fault current was less. When single core cable armor is used as grounding medium, the point and the method of armor grounding becomes critical. If both ends are earthed, circulating currents will be induced. Choose between high quality cables in copper or aluminium, single or three core, light or heavy duty screened, armoured or unarmoured, pvc, high density polyethylene or low smoke zero halogen sheathing. Armoured cable is covered by a metal sheath which protects the cable from water and extreme temperatures, allowing it to be used in underground or external projects as well as indoor applications.
Monday, august 10, 2015 alternating current flowing in a conductor sets up an alternating magnetic field which is much stronger if the conductor is surrounded by an ironrich material, for example if it is steel wire armoured or if it is installed in a steel conduit. In any armoured cable system the armour is an exposedconductivepart and has to be connected to earth as. Wide selection of quality armoured cable at which is ideal for many. Guide to lighting and power cables the engineering mindset. Swa cable, which means steel wire armoured is heavy and difficult to bend which helps to reduce the risk of pinching and damage. If single core cable armor is grounded at both ends through cable glands, continuous high circulating armor currents may create high temperatures at armor. Often single phase connections will use 3 core as its nearly the same price as 2 core and the electrician will use the 3rd core as earth. In a single core cable, there is no cancelling effect, so. For multi core cables steel wire armour is most often used. Armoured cable swa and awa cable products steel wired. Use of armoured single core cables in hv installations may be the designers choice.
When cable has only one core, aluminium wire armour awa is used instead of steel wire. It is possible to improve existing speakers bringing new life with new cables and leads. The earthing is obtained from an earth rod and the cu, hot tub and other peripherals are all ttd. On trays or racks hv cables shall be segregated from the lv cables. It should be noted, however, that the armour provides no protection for climatic conditions.
Our wide range includes submersible pump cables, earthing cables, heavy duty single core power cable, welding cables, battery cables, multi core flexible cables and earthing conductors among others. Is it okay to have single end earthing in the 11 kv single core cables of around 3. Armor of single and multi core cable going to junction box shall be terminated at cable gland. The thickness of the protective conduits must be at least 4. Single core cables produce a magnetic field which induce current and losses in steel. Find great quality conduit cables, coaxial cables, cable reels, twin and earth cables, 3core and earth cables, armoured cables, ethernet cables and more. Bs5467 single core xlpe awa power cable 600v data sheet. Hardwearing power cables armoured cable or as it is better known swa steel wired armoured or awa aluminium wired armoured is a hardwearing power cable specifically designed for the supply of the mains cable, the armour provides mechanical protection allowing the cable to withstand higher stresses, be buried directly, and can be used in internal, external and underground projects. The metallic sheath and armour of multicore cables shall be bonded together and earthed. Figure 11 singlecore cables supplied twisted together to form a.
Medium voltage single core cable armor grounding issues. What means by circulating current in single core cable. And, in single core cables, there would not be any compensating flux from any neighbouring core and thus there would be appreciable residual flux available for linking with the armour and, if the armour is made of a magnetic material, such a resultant flux would induce. Single core cables up to and including 800 mm2 3 core cables up to and including 400 mm2 applicable standards iec 60502 part 2 xlpe insulated cables single core 3 core bs 6622 for xlpe insulated armoured cables any other customer of international standards e. 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. For a better experience on riyadh cables group company, enable javascript in your browser. Current rating for xlpe land cable systems continuous current ratings for single core cables are given in tables 14. Armoured cables are often referred to as steel wire armoured cables, swa cable, mains power cable, single core power cable, and multi core booklet armoured cable.
Bs5467 cables are widely used power cables both in the uk and prevalent in international projects specified to british standards. Steel wire armour is only used on multi core cables. Three core cable is for class i or single insulated which must have earth. If the junction box made from metal, then it only needs to connect the earth stud bolt to the nearest steel structure. This is a training video for single core medium voltage heat shrink terminations. Bs5467 cable low voltage bs5467 swa xlpe armoured power. A wide variety of earthing cable specification options are available to you, such as conductor material, conductor type, and type. On larger cables it is moreorless mandatory to use an additional copper conductor because the armour does not have adequate crosssection. Riyadh cables is among the regions leading manufacturers of wires and cables for use in power, lighting and internal wiring for homes and offices.
Cable earthing conductors shall be copper strip with appropriate section laid in formed cable trenches or ducts, or fixed to walls, concrete or steel work, by means of clamps or claw type cleats, appropriately secured into suitable wall plugs or tapped holes. In a three phase cable, the sum value of the three magnetic fields is zero. We stock a huge range of highquality electrical cables that are suitable for indoor, outdoor and underground installation. Mv cable accessories installation best practice ensto. This would induce an electric current in the steel wire, which could cause overheating. Method of electrical earthing and bonding multicore cables. Earthing on single core cables with aluminium wire armours. Other installations, such as buried and aerial, have different installation parameters. The insulation level for cable for unearthed system has to be more. The armour also enables the cable to withstand higher pulling loads. In general used, the earth bus bar is made from copper and. The flex cable flexible cord cable has three cores being live, earth and neutral. Note that cables installed on unperforated cable trays are classified under method c. I have tested the advocates of the use of 3 core cables on single phase as to why they think 2 core cable is correctly coloured for single phase use.
The suppliers earth is only being used to protect the feeder cable by using the third core and connecting it to the armour. If the remote building has an alternative means of earthing then the swa armour or separate cpc would need to. Two core and earth cable new colours two core and earth cable old colours. Armour earth continuity for xlpeawa single core joints. Use of aluminium wire armour for single core cables cr4. About 42% of these are electrical wires, 31% are power cables. Exporter and manufacturer of power cables, armoured power cables, unarmoured power cables, armoured electrical cables, pvc armoured cables, xlpe armoured cables, unarmoured cable, armoured control cable from grid india power cables private limited, gurgaon, haryana, india. Single core high voltage xlpe cables represent an extended capacitance with a homogenous. High voltage xlpe cable systems technical user guide. Earthing method standing voltage at cable ends sheath voltage limiters required typical application bothend bonding no no. I have used sea for 40 odd years and have always specified a three core for single phase and 5 core for three phase.
The swa is supplying the outdoor consumer unit with a line and neutral only. Audio cables and leads carry electrical current between the speakers and amplifiers. You connect the armour to earth so that should the cable be penetrated, the chances are the fault current will go down the armour and trip the protection. Iet forums connections of single awa cable from private. Where it is intended to connect the cables in this table to equipment or accessories designed to operate at a temperature lower than the maximum operating temperature of the cable, the cables should be rated at the maximum operating temperature of the equipment or accessory see regulation 512. A magnetic field is produced by the current in a single core cable. Tf trifurcating set to seal 3 core armoured cables. Earthing on single core cables with aluminium wire armours awa if single core aluminium wire armoured awa cables are earthed only at one end, a voltage will appear at the other end.
So depending on the circumstances, either method may be ok. Hv and lv single core cables shall be laid in trefoil groups with 150 mm clear spacing between trefoils. Multi core swa cable, is a cable with two or more cores. They are hardwearing and suitable for indoor, underground direct burial in free draining soil or embedded in concrete and outdoors without additional protection due to the mechanical protection afforded by their armour and the uv stable and water resistant nature. The main purpose of armour is to provide mechanical protection, although it can also provide part of the earth fault path.
1006 1217 430 810 808 602 302 1614 886 146 557 1207 1127 1146 1207 319 618 287 1281 1090 175 1143 1440 1132 814 525 1491 1388 146 262 1393 859 1266 289 1046 1341 485 633 592 730 1158 1225 1405 892 1340 193 313