Posts Tagged ‘hardware’
Air Cable
Sunday, July 17th, 2011
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
|
|
Jump-N-Carry JNC300XL 900 Peak Amp Ultraportable 12-Volt Jump Starter with Light $55.21 Ultra-portable jump starter can be stored virtually anywhere and weighs just 9 lbs. Delivers 900 Peak Amps of jump starting power 27″ #4 gauge cables provides efficient power transfer to vehicle’s battery Built-in flashlight is great for emergencies and everyday use 12 Volt outlet to power accessoriesA great balance of power and portability, the SOLJNC300XL packs the punch of 900 Peak Amps of sta… |
|
|
CDN Digital Programmable Probe Thermometer $19.19 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… |
|
|
Lifeline First Aid AAA Explorer Road Kit … |
|
|
Cars 2 (Five-Disc Combo: Blu-ray 3D / Blu-ray / DVD / Digital Copy with Lightning McQueen Globe) $33.99 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] $29.97 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] $60.00 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… |
|
|
Kintrex IRT0421 Non-Contact Infrared Thermometer with Laser Targeting $41.16 The IRT0421 Non-Contact Infrared Thermometer with Laser is designed to accurately measure temperature from a distance. Simply pull the trigger and aim the pistol grip thermometer at an object using the laser indicator and the unit will provide an accurate temperature measurement in less than a second. The IRT0421 has an advanced highly accurate infrared sensor with a Distance to Spot Ratio of 12 t… |
|
|
Andis RC-2 Ionic 1875W Ceramic Hair Dryer with Folding Handle and Retractable Cord $19.99 ANDIS ECO HAIR DRYER TOURMALINE IONIC CERAMIC… |
|
|
Microlife PF 100 Peak Flow Meter for Spirometry with FEV1 $38.98 This device is used to measure Peak Expiratory Flow (PEF) and Forced Expiratory Volume in 1-second (FEV1) in both children and adults. PEF is the fastest speed air can be blown out of the lungs after inhalation. FEV1 measures the volume after exhaling in 1-second. Peak Flow (PEF) and Forced Expiratory Volume in 1-second (FEV1) measurements can tell how well lungs are breathing by monitoring airflo… |
|
|
HONEYWELL HCM890 Cool Moisture Duracraft Humidifier $26.35 KAZ COOL MOISTURE HUMIDIFIER *Automatic moisture balance system *Low/high moisture output settings *Clear tank *Easy to fill, carry and clean *High impact packaging *Replacement filter is Ace No. 4237962… |
