Lesson 8: Grounding Electrical Equipment

If equipment is located more than ? vertically and ? horizontally from ground or grounded objects and not subject to contact by persons, grounding is not required.

1. 8' / 5' 2. 10' / 6'

The mounting strap or yoke of a snap switch can serve as an effective ground-fault current path under which of the following conditions?

1. An EGC or equipment bonding jumper is connected to an equipment grounding termination 2. The switch is mounted with metal screws to a metal box or metal cover that is connected to an EGC or to a nonmetallic box with integral means for connecting to an EGC.

Which of the following types of nonelectrical equipment are required to be grounded if likely to be energized?

1. Frames and tracks of electrically operated cranes and hoists 2. Frames of non-electrically driven elevator cars to which electric conductors are attached 3. Hand-operated metal shifting ropes or cables of electric elevators

For existing range and dryer circuits, the grounded conductor (neutral) is permitted to be used for grounding under which of the following conditions?

1. Grounding contacts of receptacles furnished as part of the equipment are bonded to the equipment. 2. The grounded conductor is insulated, or the grounded conductor is uninsulated and part of a Type SE (service-entrance) cable and the branch circuit originates at the service equipment. 3. The grounded conductor is not smaller than 10 AWG copper or 8 AWG aluminum. 4. The supply circuit is 120/240-volt, single-phase, 3-wire, or 208Y/120-volt derived from a 3-phase, 4-wire, wye-connected system.

Which of the following is permitted as a substitute for grounding electrical equipment under certain conditions?

1. Guarding 2. Insulation 3. Isolation

A GFCI receptacle device is permitted as a replacement for a non-grounding-type receptacle under which of the following conditions?

1. No equipment grounding conductor is installed from the GFCI device to any receptacle outlet downstream. 2. No equipment grounding means exists in the outlet. 3. The GFCI device is marked at the outlet to indicate "No Equipment Ground."

The general requirements and specific requirements for equipment grounding are provided in which part of NEC Article 250?

1. Part I 2. Part VI

If a submersible pump in a metal well casing is protected at 30 amperes, the equipment grounding conductor connected to the motor and the well casing must not be smaller than ? .

10 AWG copper

The equipment grounding conductor for a range circuit protected by a 40-ampere circuit breaker must not be smaller than ? .

10 AWG copper

What is the minimum size required for an isolated/insulated equipment grounding conductor installed for a 30-ampere single receptacle on an individual circuit protected at 30 amperes?

10 AWG copper

If a metal component, such as a metal elbow, is installed in a run of PVC conduit and encased in ? of concrete, the metal component is not required to be grounded.

2"

If a 200-ampere feeder is installed from a service to a panelboard in a building and is run in PVC conduit, a minimum ? copper equipment grounding conductor is required.

6 AWG

Type SE (Style U) cable that contains a bare conductor normally used for a grounded conductor of a circuit or service is permitted to supply which of the following?

A 240V water heater

Which of the following is generally not permitted to be used for grounding panelboards on the load side of the service disconnecting means?

A grounded conductor (usually the neutral)

In which of the following receptacle installations is an equipment bonding jumper or conductor required to be connected from the grounded outlet box to a grounding type receptacle?

A metal box installed in a wall with drywall surface and a standard grounding receptacle is installed

All receptacles installed on 15- and 20-ampere branch circuits shall be of the grounding type.

False

Equipment grounding terminal bars are required in every panelboard even if there are no wire-type equipment grounding conductors installed in the panelboard.

False

If a power factor correction capacitor is mounted on top of a wood pole at a height of 15 feet above ground (earth), the metal capacitor case is required to be grounded.

False

If an isolated grounding-type receptacle is installed, an insulated equipment grounding conductor is required to be installed from the receptacle grounding terminal to the applicable grounding point at the service or separately derived system without connection to any panelboard or other enclosure in the circuit.

False

If equipment is double-insulated, it must be connected to an equipment grounding conductor of the branch circuit.

False

Separable connections, such as those made with receptacles and attachment plugs, are required to be designed and proved for a "last-make" and "first-break" connection of the equipment grounding conductor of the circuit.

False

The interconnected metal frame of a building is permitted to be used as an equipment grounding conductor for branch circuits and feeders under controlled conditions in industrial installations only.

False

Where a short length of metal raceway is installed as a sleeve or for physical protection of a cable wiring method, it is required to be grounded.

False

Flexible cords having an integral insulation and jacket without an equipment grounding conductor are permitted to have a continuous outer finish that is green with one or more yellow stripes.

False 250.119 Exception No. 2

The grounded conductor is permitted for grounding equipment in all but which of the following locations?

In the first panelboard on the load side of the service disconnecting means

Based on the NEC, which of the following is not permitted as a method for identifying the receptacle equipment grounding conductor connection point if the connection point is not visible?

The words "Equipment Ground"

The non-current-carrying metal parts of cord-and-plug-connected equipment that are likely to be energized are not required to be grounded by connection to the equipment grounding conductor of the branch circuit under which of the following conditions?

They are listed equipment protected by a system of double insulation and are distinctively marked.

A non-grounding-type receptacle is permitted to be replaced with another non-grounding-type receptacle only when the outlet does not include an equipment grounding conductor.

True

An equipment grounding conductor is not required to be connected to receptacles that are installed in listed floor boxes that provide satisfactory grounding continuity.

True

Grounding equipment places equipment at or as close to earth potential as possible, which minimizes possible shock hazards and limits voltage to ground due to unintentional contact with higher voltage lines or due to line surges or lightning events.

True

If equipment is supplied by a Class 1 power-limited circuit or system that is grounded, the equipment is also required to be grounded.

True

Separate equipment grounding conductors are required for all new dryer and range circuits installed in dwelling units.

True

The branch circuits installed for wall-mounted ovens, counter-mounted cooking units, ranges, dryers, and associated outlet or junction boxes are required to be connected to an equipment grounding conductor and have to include an insulated grounded circuit conductor if it is needed based on the load served.

True

The color green shall be permitted for use as the ungrounded signal conductor between the output terminals of traffic signal control equipment and the traffic signal heads where an equipment grounding conductor in accordance with 250.118 is installed or a wire-type EGC that is bare or green with one or more yellow stripes is installed.

True

The earth is not permitted as an effective ground-fault current path even if no equipment grounding conductor is installed.

True

The mounting strap of a snap switch is not required to be grounded if the switch is provided as part of a listed kit or assembly with a non-standard nonmetallic faceplate mounting means.

True

Where a metal floor box is designed for and listed as providing satisfactory ground continuity between the box and a grounding receptacle, a wire-type equipment bonding jumper is not required between the grounded floor box and the grounding-type receptacle.

True

Wiring devices such as receptacles and switches are generally required to provide a terminal for connecting an equipment grounding conductor to the device. This grounding terminal can be identified by any one of the following methods except ? .

a green screw that has a round head

A(n) ? is defined as a reliable conductor used to ensure the required electrical continuity between metal parts required to be electrically connected.

bonding conductor or jumper

Where a separate equipment grounding conductor is installed to a receptacle outlet that has no equipment grounding means, as permitted in Section 250.130(C), the separate equipment grounding conductor is permitted to be connected to any of the following except ? .

the grounded metal service riser mast