Air Cable
Author: admin
Aerial cable
Distinguish from “cable running to an aerial”.
Air cable redirects here. Distinguish from usage in subscription television services.
An air cable is an insulated cable usually containing all conductors required for an electrical transmission system or a telecommunication line, which is spun between utility poles or pylons. As air cables are completely insulated there is no danger of electrical shocks when touching them and there is no requirement for mounting them with insulators on pylons and poles. A further advantage of air cables is, that they require less right of way than overhead lines for the same purpose. They can be designed as shielded cables for telecommunication purposes. If the cable falls, it may still operate if its insulation is not damaged.
As air cables are installed on pylons or poles, they may be cheaper to install than underground cables as no work for digging is required, which can be very expensive in rocky areas.
Use
Air cables are mostly used for telecommunication systems or for power transmissions with voltages below 1000 volts. Air cable for voltages around 10000 volts have also been built, for the supply of farms, waterworks, transmitters and other facilities outside urban areas. A further common use is the replacement of overhead telecommunication lines, for example, along railway line, by air cables as they can be installed on existing poles and make the facility more reliable.
Telecommunication systems running along power lines or aerial tramways are often built as air cables as they can be easily installed on the pylons or tramway support towers. However these cables must be designed for higher forces as span lengths are longer.
As powerlines the air cable can serve also as ground conductor on the top of the pylon. It can be also installed in form of a separate strand on the conductor. A special method was used at former EVS ( now EnBW)in Germany until the mid 1980s, where the air cable was installed like a garland on the ground conductor or an auxiliary rope.
Air cable spun like a garland on a 110kV-powerline of EnBW AG near Leonberg in Germany
For reasons of electromagnetic interference air cables running along powerlines are most often of fibreoptic types. As these are dielectric, it is even possible to install them directly in the conductors.
Air cables are also used sometimes for power transmission from the transmitter building to the antenna at radio stations.
See also
overhead powerline
Categories: Power cables | Electricity distribution
About the Author
I am a professional writer from China Bags Wholesale, which contains a great deal of information about manual coin counter , manual coin sorter, welcome to visit!
Cable Air Show 2011 Clips
|
|
CDN Digital Programmable Probe Thermometer $23.62 If you’ve ever opened the oven door to check on a roast only to watch the heat escape while an “instant read” thermometer measures temperature, you’ll appreciate this impressively-accurate, remote cable thermometer. Simply insert its high-heat stainless steel probe into meat, shut the oven door, and monitor internal food temperature on a large, easy-to-read digital display. You can even program an… |
|
|
Koolatron Multi-Purpose Adapter 110AC to 12 Volts DC ( Model AC-15) $29.99 Power your Koolatron(r) Cooler/Warmer at home or office with this AC Adapter. For use with all Koolatron(r) 12V Coolers and warmers and other 12V items. Over-load and over-charge protected…. |
|
|
115V AC Cooling Fan. 120mm x 38mm HS with Power Plug $15.99 Overview The high speed 120 by 120 by 38 millimeter 115V AC axial fan is housed in die cast aluminum with thermoplastic blades. Containing long life dual ball bearings, the fan can run continuously for 67,000 hours and be mounted in any direction. Includes a 4 foot power cord which allows the fan to be plugged into a standard outlet. Cooltron fans are certified by CE, UL, TUV, and RoHS; and found … |
|
|
Antennas Direct DB8 Multidirectional HDTV Antenna $64.59 This powerful multidirectional HDTV antenna lets you receive over-the-air high-definition signals and features up to a 15.8dB gain for improved reception…. |
|
|
The Canadian Brass – High, Bright, Light & Clear: the Glory of Baroque Brass $12.99 … |
|
|
Messiah $5.98 … |
|
|
Cars 2 (Five-Disc Combo: Blu-ray 3D / Blu-ray / DVD / Digital Copy with Lightning McQueen Globe) $34.75 The Collector’s Combo Pack box set includes Blu-ray 3D, Blu-ray, DVD and Digital Copy editions of the film, plus a Lightning McQueen glowing globe! From the creators of Cars and Toy Story 3 comes a new, laugh-out-loud, heartwarming adventure in a high-octane 5-disc Combo Pack. Star race car Lightning McQueen (Owen Wilson) and the incomparable tow truck Mater (Larry the Cable Guy) take their friend… |
|
|
Cars 2 (Blu-ray Combo Pack Gift Set) [Blu-ray] $29.00 From the creators of Cars and Toy Story 3 comes a new, laugh-out-loud, heartwarming adventure in a high-octane 2-disc Combo Pack. Star race car Lightning McQueen (Owen Wilson) and the incomparable tow truck Mater (Larry the Cable Guy) take their friendship on the road from Radiator Springs to exciting new places when they head overseas to compete in the first-ever World Grand Prix to determine the… |
|
|
Cars 2 (5-Disc Combo Pack + Exclusive LEGO Bonus Disc) [Blu-ray 3D + Blu-ray + DVD + Digital Copy] Toys “R”Us exclusive edition including an exclusive LEGO Cars 2 bonus disc featuring animated shorts, videos and more. From the creators of Cars and Toy Story 3 comes a new, laugh-out-loud, heartwarming adventure in a high-octane 5-disc Combo Pack. Star race car Lightning McQueen (Owen Wilson) and the incomparable tow truck Mater (Larry the Cable Guy) take their friendship on the road from Radiato… |
|
|
Toro 51585 Power Sweep 7 amp 2-Speed Electric Blower $34.96 7.0A motor generates a powerful air speed of 160 mph with a minimum speed of 130 mph. Air volume at 155 cfm. 2 speed air control is perfect for clearing leaves and debris from sidewalks, decks, and driveways. Lightweight and easy to use. Unit weight: 4.6 lb. 2 year warranty…. |
