2-5-8 Flashcards
The layer of a medium or high voltage shielded power cable that must be grounded is the cables __?__.
metalic sheild
If no grounding specifications are available for a cable installation, the ground(s) should be located at __?__, as well as aerial pole-mount locations.
access point
Cables are usually grounded at cable accessories because they share the same grounding locations.
true
Most cable accessory kits contain instructions and materials for making a ground connection. These materials must be used for grounding at the job site location.
false
When grounding is not specified, it is common practice to ground at each __?__. (Check all correct answers.)
elbow, splice, termination
The ground conductor size that has traditionally been recommended for non-specified jobs is __?__ AWG, which can be solid copper or ground braid.
6
For single-point grounding, the cable is grounded at only one location, usually at a __?__.
termination
Single-point grounding is used to prevent induced currents (circulating currents), by eliminating a closed-circuit (loop) of ground conductors.
true
Single-point grounding is usually limited to relatively __?__.
short runs
One disadvantage of single-point grounding is that the full magnitude of any fault is forced down __?__ to ground.
a single path
Double-end grounding reduces fault currents by dividing the current between the two grounds.
true
A shield break disrupts the shield continuity of a termination or splice. To prevent shield breaks on splices and terminations, the __?__.
shielding is overlapped
A shield break disrupts the shield by overlapping the shield ends and separating them with a layer of insulation. This leaves the cable or splice fully shielded radially, but without __?__.
longitudinally continually
Cross bonding has two advantages, one of single-point grounding by neutralizing shield currents, and also the advantage of double-end grounding, by reducing __?__.
falut current
Shield cross bonding is connected among the three phases of a circuit by connecting __?__ across the breaks.
insulated jumpers
A government agency which provides regulations and standards for rural electric utilities is known as the __?__
rural utility service
The Quarter Mile Grounding rule for rural electric utilities for direct buried, jacketed distribution cables is that they must have at least __?__ grounds per mile, minimum.
4
In addition to the standard shield functions, concentric neutral wires also serve as a current carrying component of the electric circuit, by providing a path for the return current.
true
The ground wire used for connecting a concentric neutral cable to ground is __?__.
the entire concentric itself
On a premolded splice or elbow, the bleeder wire’s function is to minimize any voltage drop formed across a splice’s or elbow’s semi-conducting jacket, thereby dissipating any unsafe voltage to ground.
true
The traditional method for connecting a cable accessory’s metallic ground to a cable’s metallic shield is by __?__.
soldering
Most contemporary cable accessory kits eliminate the need to solder. The most common solderless ground connection provided in kits today is the __?__.
constant force string
