Type of Ground Connectors

Question 1

Exothermic welding cannot be used on copper wire-to-steel connections because these are two different metals

Answer 1

false

Question 2

After igniting the powder in an exothermic mold, one should wait approximately ? for the weld to cool and solidify before opening the mold.

Answer 2

30 seconds

Question 3

The recommended ignition source for exothermic welding is a ? .

Answer 3

flint-type spark generator

Question 4

The extreme temperatures of exothermic reactions produce temperatures of ? in the crucible of the mold.

Answer 4

4,000°F

Question 5

Of the most commonly used connections, the ? type presents the greatest hazards to the substation worker during installation.

Answer 5

exothermic weld

Question 6

When making connections in an existing substation, a person can be subject to electric shock when bridging across a point in the grid. Which of the following is the proper safety procedure?

Answer 6

Use a temporary jumper before making the permanent connection.

Question 7

Which of these statements regarding wedge type connections is true?

Answer 7

There are no temperature or weather restrictions.

Question 8

IEEE 80 rates the maximum allowable temperature limits for welded connections on ground grids only.

Answer 8

False

Question 9

A bonding of the conductors at a molecular level is the result of a(n) ? type connection.

Answer 9

exothermic

Question 10

After the area to be connected is cleaned, the application of conductive grease is necessary if ? connectors are used. This type of connector is normally shipped dry.

Answer 10

C-clamp

Question 11

When engineers select the type of connectors to be used, they take into account the maximum fault current that will be imposed on the connectors and the ? of the connectors.

Answer 11

temperature limits

Question 12

Over tightening of a mechanical wedge type connector is avoided by the ? .

Answer 12

bolt head that shears off when fully tightened

Question 13

The presence of ? in an exothermic mold will result in an explosion when the metal powder is ignited.

Answer 13

water

Question 14

The trademark name of a manufacturing company specializing in exothermic connections is ? .

Answer 14

Cadweld

Question 15

The exothermic welding process uses powdered metals such as copper oxide and ? to produce the chemical reactions necessary.

Answer 15

aluminum

Question 16

A wedge connector produces a molecular bond with a current-carrying capability equal to or greater than that of the conductors being joined.

Answer 16

False

Question 17

A substation ground grid is typically constructed ? below the finish grade.

Answer 17

12” to 18”

Question 18

Graphite is used to make an exothermic mold.

Answer 18

True

Question 19

Carbon traces found when inspecting exothermic connections is evidence of ? .

Answer 19

oil on the cable strands

Question 20

Cotton gloves should always be worn when making exothermic welds.

Answer 20

False