ground grids

Question 1

Soils with high conductivity have the ability to dissipate power surges. A type of soil with this property is ?

Answer 1

clay

Question 2

The resistivity of the soil determines the ? in the ground grid.

Answer 2

spacing between cables

Question 3

The grounding network for a transmission substation is typically made from bare copper in a grid pattern with conductors spaced about ? apart.

Answer 3

10’

Question 4

An ongoing testing program is required when ? are used as a method to lower the resistance of a substation grounding grid.

Answer 4

soil additives

Question 5

The most effective method of reducing the resistance of a ground grid is by ?

Answer 5

increasing the grid area

Question 6

Having a grid that bonds structures, equipment, and fencing reduces the risk of ? between different elements.

Answer 6

potential differences

Question 7

The minimum conductor size for a distribution substation ground grid is typically ? copper.

Answer 7

1/0

Question 8

The grid network for a transmission substation is typically made from ? bare copper.

Answer 8

4/0

Question 9

The final substation surfacing material is a ? layer of crushed stone.

Answer 9

3’’ to 6’’

Question 10

Because of the failure possibility during a high fault current event, ? ground grid connections are not allowed.

Answer 10

soldered

Question 11

When a fault occurs in a substation or on one of the circuits feeding in or out of the substation, ?

Answer 11

a voltage rise in the earth and ground grid occurs