Grounding and Protective Grounds

Question 1

System grounding on a power system means electrically connecting the ? of every wye-connected transformer or generator to earth.

Answer 1

Neutrals

Question 2

Under normal conditions, an electrical system delivers power without good grounding.

Answer 2

true

Question 3

Good system grounding can ? a dangerous voltage rise that can occur on the neutral and everything connected to it.

Answer 3

limit

Question 4

Good system grounding provides both protection for people and ?

Answer 4

circuit protection

Question 5

To improve the likelihood of a circuit breaker, recloser, or a fuse tripping out the circuit for a phase-to-ground fault, ? is/are essential.

Answer 5

Good grounding

Question 6

A ? device is installed to reduce step and touch potentials around equipment such as a pad-mount transformer or a switching station

Answer 6

ground-gradient control grid

Question 7

Crushed rock is used around equipment in a substation because it ? under the feet of workers.

Answer 7

increases electrical resistance

Question 8

Grounding the system neutral at frequent intervals provides a good return path for current from a line-to-ground fault.

Answer 8

true

Question 9

Grounds are connected from transformer tanks and metal clad equipment to earth because grounding reduces ?

Answer 9

shock hazards

Question 10

When a energized circuit neutral is cut or opened, voltage can be ? the circuit voltage across the open point.

Answer 10

equal to

Question 11

Wire used as a down ground to a ground rod on a single bushing transformer may be opened at any time without fear of electrocution.

Answer 11

False

Question 12

All the current leaving a source must return to the source to form a complete circuit.

Answer 12

True

Question 13

In a balanced 3-phase circuit, the return flow occurs in the ?

Answer 13

phase conductor

Question 14

In a single-phase, wye-distribution circuit, the current finds its way back to the source through the ?

Answer 14

neutral

Question 15

During a ground fault, the current uses the ? as return paths to flow back to the source.

Answer 15

neutral and earth

Question 16

Under a ? condition, the voltage on a neutral can become very high.

Answer 16

Line to Ground fault

Question 17

If a live conductor falls to the ground, the fuse or breaker will open and isolate the line if there are frequent groundings of the neutral to good earth.

Answer 17

true

Question 18

Good grounding does not help to dissipate a voltage (lighting) surge.

Answer 18

false

Question 19

The ground resistance of a driven ground rod should be low, preferable below ?

Answer 19

25 ohms

Question 20

The best place to install a ground rod is in ?

Answer 20

Loam

Question 21

If investigating tingle voltage, high-neutral voltage, excessive vulnerability to lighting, or failure of protective switchgear to operate, first measure the ground resistance with an instrument such as a clamp-on tester.

Answer 21

True

Question 22

A system of grounding called “counterpoise” is normally made of ? seven-strand soft-drawn copper.

Answer 22

1/0

Question 23

A “swinging” ground on a primary circuit is a way of describing a ground that is intermittent and is present at irregular intervals

Answer 23

True

Question 24

? is due to differences in the potentials of copper and steel is buried in the soil.

Answer 24

Galvanic Action