Cables
How to locate underground faults on cable?
A common approach to test cable and determine insulation integrity is to use a Hi-pot test. In a hi-pot test, a DC voltage is applied for 5 to 15 min. IEEE-400 specifies that the hi-pot voltage for a 15-kV class… Read more
Oct 04, 2011 | By Edvard Csanyi
Cables
Ionization (Corona Discharge) Tests
The ionization test is used primarily for detecting ionization (corona discharge) and slot discharge in generator windings. Both ionization and slot discharge may cause deterioration of insulation. Ionization generally occurs in voids inside the insulation within the ground shield section… Read more
Sep 24, 2011 | By Edvard Csanyi
Cables
Understanding Underground Electric Transmission Cables
Underground cables have different technical requirements than overhead lines and have different environmental impacts. Due to their different physical, environmental, and construction needs, underground transmission generally costs more and may be more complicated to construct than overhead lines. The design… Read more
Sep 21, 2011 | By Bipul Raman
Cables
General considerations when choosing power cable
Thousands of cable types are used throughout the world. They are found in applications ranging from fibre-optic links for data and telecommunication purposes through to EHV underground power transmission at 275 kV or higher. Certain design principles are common to… Read more
May 04, 2011 | By Edvard Csanyi
Cables
Polyvinyl chloride (PVC) as jacketing material
PVC is the most widely used nonmetallic jacketing material in the wire and cable industry. Starting in 1935, when it first became available, the use of PVC grew rapidly because of its low cost, its easy processing, and its excellent… Read more
Apr 04, 2011 | By Edvard Csanyi
Cables
Offshore wind farms – transmission cables
The European wind power industry is increasingly turning to the offshore wind resource, and the United States will draw on the Europeans’ experience as we begin to plan offshore wind farms. Short of generating hydrogen, or otherwise using or storing… Read more
Mar 23, 2011 | By Edvard Csanyi
Cables
Electrical Wire – How It’s Made
Wikipedia: Electrical wiring in general refers to insulated conductors used to carry electricity, and associated devices. This article describes general aspects of electrical wiring as used to provide power in buildings and structures, commonly referred to as building wiring. Cant… Read more
Feb 03, 2011 | By Edvard Csanyi
Cables
Oxidation Of Conductors
High-resistance oxides form very quickly on aluminum and copper conductors expose to air. Once the oxides are stabilized, they prevent further oxidation of the parent metal; however, due to this high electrical resistance, these oxides must be broken or removed… Read more
Jan 16, 2011 | By Edvard Csanyi
Cables
Comparison Of Cable Insulating Materials
Electrical insulation materials are employed over the metallic conductors of underground cables at all voltage ratings. Polymeric materials are employed as the insulation, but the nature of the polymer may vary with the voltage class. Since paper insulation was used… Read more
Jan 03, 2011 | By Edvard Csanyi
Cables
Shielding Of Power Cables
Medium and high-voltage power cables, in circuits over 2000 volts, usually have a shield layer of copper or aluminum tape or conducting polymer. If an unshielded insulated cable is in contact with earth or a grounded object, the electrostatic field… Read more
Dec 12, 2010 | By Edvard Csanyi
Cables
Types of Underground Lines
There are two methods of installing underground lines. In the first method, underground raceway systems (ducts) are installed below grade and then cable is pulled through them. Ducts may or may not be provided with concrete encasement. The second method… Read more
Oct 22, 2010 | By Edvard Csanyi
