ch 5

Question 1

The ? is/are defined as the conductors and equipment for delivering electric energy from the serving utility to the wiring system of the premises served.

Answer 1

service

Question 2

Where a system is grounded, the service must be supplied with a(n) ? conductor.

Answer 2

grounded

Question 3

What is the minimum-size aluminum main bonding jumper (wire-type) for a service if the largest ungrounded service conductor is 500 (kcmil) copper?

Answer 3

1/0 AWG

Question 4

The grounded conductor of a service must always be a neutral conductor.

Answer 4

false

Question 5

Where the utility transformer supplying a service is located outside the building, a grounding connection is not required to be made outside a building or structure served by a grounded electrical service.

Answer 5

false

Question 6

A grounding electrode connection is required to be made at a(n) ? location anywhere from the load end of the overhead service conductors, service drop, underground service conductors, or service lateral up to and including the terminal or bus to which the grounded conductor is connected in the service disconnecting means.

Answer 6

accessible

Question 7

A meter socket enclosure sealed by the utility makes the enclosure inaccessible, by definition.

Answer 7

false

Question 8

Which of the following is not one of the four conductors in the grounding and bonding scheme for a service supplied by a grounded system?

Answer 8

System bonding jumper

Question 9

Where a service is supplied by an ungrounded system, the grounded conductor is required to be routed to the service disconnecting means enclosure and bonded to it.

Answer 9

false

Question 10

Where a service is supplied by a grounded system, the grounded conductor is required to be routed to the service disconnecting means enclosure and bonded to it.

Answer 10

true

Question 11

The grounded conductor is required to be routed to the service equipment along with its associated ungrounded service conductors.

Answer 11

true

Question 12

The main bonding jumper in a service disconnecting means enclosure can be in which of the following forms?

Answer 12

Bus

Green screw

Wire

Question 13

If a service disconnecting means is made up of six disconnects in separate enclosures, how many main bonding jumpers will be required for the service?

Answer 13

6

Question 14

Where the service disconnecting means is made up of two to six disconnects in a single listed service equipment assembly, how many main bonding jumpers are required within the listed assembly?

Answer 14

1

Question 15

If a main bonding jumper is a wire type, what NEC table is used to size it?

Answer 15

Table 250.102(C)(1)

Question 16

The grounded neutral conductor serves which two purposes for a grounded service?

Answer 16

Carries the maximum unbalanced return neutral load

Serves as an effective ground-fault current path in gro

Question 17

If a main bonding jumper is a screw, the screw is always required to be identified using the color green.

Answer 17

true

Question 18

The ? is a conductor connected to the neutral point of a system that is intended to carry current under normal conditions.

Answer 18

neutral conductor

Question 19

For a grounded service, the ? is the intentionally constructed, low-impedance, effective ground-fault current path addressed in 250.4(A).

Answer 19

grounded conductor

Question 20

If the ungrounded service conductors are 600 kcmil copper, what is the minimum size required for the grounded conductor supplying the same service?

Answer 20

1/0 AWG

Question 21

Where a service is supplied from a corner-grounded system, and the ungrounded conductors are sized at 750 kcmil copper, what is the minimum size required for the grounded conductor?

Answer 21

750 kcmil copper

Question 22

Where a grounded service is supplied using two 500 kcmil copper conductors in parallel (in two separate raceways) for each ungrounded service conductor, what is the minimum size required for the grounded conductor in each raceway supplying the service?

Answer 22

1/0 AWG

Question 23

Which of the following characteristics are required for ungrounded conductors installed in parallel?

Answer 23

Must be not smaller than 1/0 AWG (generally)

Must be the same conductor material

Must be the same insulation type

Must be the same length

Same size

Terminated the same

Question 24

Grounding connections to the grounded conductor are generally not permitted on the load side of the service equipment enclosure.

Answer 24

true

Question 25

A grounded conductor (often the neutral) larger than 6 AWG is required to be identified by which of the following methods?

Answer 25

A bare conductor that is part of a listed service-entrance cable assembly

A continuous white or gray outer finish

A distinctive white or gray marking at terminations that encircles the conductor

Three continuous white or gray stripes along its entire length on other than green insulation

Question 26

The service disconnecting means used for a grounded supply system is required to be listed as suitable for use as service equipment.

Answer 26

true

Question 27

Service equipment that is listed as suitable for use only as service equipment always includes a main bonding jumper.

Answer 27

false

Question 28

The NEC requires that a(n) ? be provided in the grounded conductor for service equipment.

Answer 28

disconnecting means

Question 29

If a service switchboard is supplied from an ungrounded 240-volt system, which of the following markings are required on the switchboard?

Answer 29

Caution: Ungrounded System Operating 240 Volts Between Conductors

Question 30

The NEC generally requires all metal enclosures and raceways for service conductors to be grounded except for metal components such as metal elbows in a run of nonmetallic service raceway that are isolated from contact by persons by not less than ? of cover to any part of the elbow.

Answer 30

18 inches

Question 31

Ground detectors are required to be installed on services supplied by ungrounded systems, and the ground detection sensing equipment must be connected as close as practicable to the service or source.

Answer 31

true

Question 32

If the size of the largest ungrounded service conductor for a service is 3,600 kcmil (six 600 kcmil conductors in parallel per phase), what is the minimum-size copper wire-type main bonding jumper required?

Answer 32

500 kcmil copper

Note: Review sizing methods for the 12.5% rule when the size of the largest ungrounded service conductor exceeds the values in Table 250.102(C)(1). Use of Table 8, Chapter 9 should be reviewed.

3600 x 12.5% = 450 kcmil

Take that value to Table 8 in the left column and find that the minimum kcmil required is 450 (larger than 400 kcmil), then round up to 500 kcmil copper.
The correct answer is: 500 kcmil copper

Question 33

Referring to the drawing, what is the minimum size required for a copper wire-type main bonding jumper for this service?

Answer 33

2 awg

Question 34

What is the minimum size required for a copper grounded conductor of a 3-phase, 3-wire, corner grounding delta system if the ungrounded phase conductors are sized at 500 kcmil copper?

Answer 34

500 kcmil

Note: Refer to Section 250.24(C)(3) to confirm the answer. The grounded conductor of this system must be not less that the size of the ungrounded conductors of this system.
The correct answer is: 500 kcmil

Question 35

Because in-ground swimming pools provide an excellent grounding connection to the Earth, when they are installed on a property, they are required to be included in, and bonded to, the grounding electrode system installed for a building or structure served.

Answer 35

false

Question 36

Where the utility transformer supplying the service is located outside the building or structure served, at least one additional grounding connection shall be made from the grounded service conductor to a grounding electrode at which of the following locations?

Answer 36

At the transformer

Elsewhere outside the building