Search results
Results From The WOW.Com Content Network
A time-domain reflectometer; an instrument used to locate the position of faults on lines from the time taken for a reflected wave to return from the discontinuity.. A signal travelling along an electrical transmission line will be partly, or wholly, reflected back in the opposite direction when the travelling signal encounters a discontinuity in the characteristic impedance of the line, or if ...
The conventionally used aid in cable fault testing and location is the cable test van. The van is installed with conventional cable measuring systems for quickly reaching the location of any cable fault. In 20 years that followed, over 2000 fault location vehicles were manufactured, more than half of which were intended for the former USSR.
In an electric power system, a fault or fault current is any abnormal electric current. For example, a short circuit is a fault in which a live wire touches a neutral or ground wire. An open-circuit fault occurs if a circuit is interrupted by a failure of a current-carrying wire (phase or neutral) or a blown fuse or circuit breaker.
A common type of ground loop is due to faulty interconnections between electronic components, such as laboratory or recording studio equipment, or home component audio, video, and computer systems. This creates inadvertent closed loops in the ground wiring circuit, which can allow stray 50/60 Hz AC current to be induced and flow through the ...
Stray voltage is the occurrence of electrical potential between two objects that ideally should not have any voltage difference between them. Small voltages often exist between two grounded objects in separate locations by the normal current flow in the power system.
This is a potentially dangerous fault condition. With ABC, a simultaneous disconnection of all conductors is more likely. In moister climates, tree growth is a significant problem for overhead power lines. ABC will not arc over if touched by tree branches. Although persistent rubbing is still a problem, tree-trimming costs can be reduced.
The lifetime cost difference is smaller for lower-voltage distribution networks, in the range of 12-28% higher than overhead lines of equivalent voltage. [12] Whereas finding and repairing overhead wire breaks can be accomplished in hours, underground repairs can take days or weeks, [13] and for this reason redundant lines are run.
Each phase of the circuit is run in a separate grounded metal enclosure. The only fault possible is a phase-to-ground fault, since the enclosures are separated. This type of bus can be rated up to 50,000 amperes and up to hundreds of kilovolts (during normal service, not just for faults), but is not used for building wiring in the conventional ...