Grounding and Bonding Flashcards
A grounding electrode system is generally required for each building or structure served by a feeder.
True
According to the NEC, that which is built or constructed, other than equipment, best defines which of the following?
Structure
If the overcurrent protective device is located on a generator outside that supplies a separate building or structure, then the feeder is on the load side of an overcurrent device. In this case, the equipment bonding jumper (load side) with the feeder is sized based on the requirements in Section 250.102(C).
False
If the overcurrent protective device is not located on a generator outside that supplies a separate building or structure, then the feeder is on the line side of an overcurrent device. In this case, the supply-side bonding jumper with the feeder is sized based on the requirements in 250.102(C).
True
A structure is constructed or built and does not include electrical equipment.
True
Which of the following electrical systems is required to be grounded?
a. 120V, single-phase system
b. 240V, 3-phase, 3-wire, delta-connected system
c. 480V, 3-phase, 3-wire, delta-connected system
d. 2,300V, 3-phase, 3-wire, delta-connected system
e. 4,600V, 3-phase, 3-wire, delta-connected system
a. 120V, single-phase system
Correct
Which of the following systems is not required to be grounded because, if grounded, the phase-to-ground voltage would exceed 150?
a. 50V, single-phase system
b. 120V, single-phase system
c. 120/240V, single-phase, 3-wire system
d. 480V, 3-phase delta system
d. 480V, 3-phase delta system Correct
Class 2 load-side circuits for suspended ceiling low-voltage power grid distribution systems are required to be supplied by grounded systems.
False
Which of the following systems is required to be grounded?
a. 120V, single-phase system
b. 240V, 3-phase, 3-wire, delta system
c. 480V, 3-phase, delta system
d. 600V, 3-phase system
a. 120V, single-phase system Correct
Where a system bonding jumper for a separately derived system is a wire type, it is required to be sized using Table 250.102(C)(1) or the 12.5% rule based on the size of the largest derived ungrounded phase conductor(s) or the total circular mil (cm) area of all conductors connected to any one ungrounded phase at the source.
True
If a generator is installed on a premises wiring system, it must be grounded as a separately derived system if there is a switching action in the grounded conductor through the transfer switch.
True
The grounding electrode conductor for a single separately derived system is required to be sized using which NEC table?
Table 250.66
The grounding electrode conductor for a single separately derived system in accordance with ? must be sized at a minimum in accordance with the sizes in ? , based on the circular mil area of the largest ungrounded system conductor.
250.33(A)(5)/ Table 250.66
Where grounding electrode conductor taps are used for multiple separately derived systems, each grounding electrode conductor tap must be sized using Table 250.66 based on the largest ungrounded derived phase conductor(s) of the individual derived system it serves.
True
Metal water piping and interconnected metal building framing that exists in the area served by a separately derived system is required to be bonded to the grounded conductor of that separately derived system, and ? is used to size this bonding jumper or conductor.
Table 250.102(C)(1)
What is the minimum size required for the bonding conductor for an equipotential plane in an agricultural facility?
8 AWG Copper
A distance of at least ? must be maintained from a nonmetallic conduit containing a high-voltage circuit operating at above 100 hertz.
1 3/4”
Remote parts of a section sign or outline lighting system supplied by a Class 2 power supply are required to be bonded to the equipment grounding conductor of the branch circuit supplying the system.
False
A(n) ? is a specific grounding and bonding device that provides a means for connecting bonding conductors for communications systems to the grounding electrode system.
Intersystem Bonding Termination
The bonding conductor or grounding electrode conductor for a communications system is required to be ? and shall be permitted to be insulated, covered, or bare.
Listed
In existing buildings or structures where any of the intersystem bonding and grounding electrode conductors required by 770.100(B)(2), 800.100(B)(2), and 810.21(F)(2) exist, installation of the intersystem bonding termination is not required. In this case, an accessible means external to enclosures for connecting intersystem bonding and grounding electrode conductors is permitted at the service equipment and at the disconnecting means for any additional buildings or structures by which one of the following means?
a. An exposed grounding electrode conductor
b. Approved means for the external connection of a copper or other corrosion-resistant bonding or grounding electrode conductor to the grounded raceway or equipment
c. Exposed nonflexible metallic raceways
d. Any of the above locations
d. Any of the above locations
Correct
Which of the following are common shock severity factors for humans?
a. Amount of current
b. Frequency of the circuit
c. Length of time
d. Path across the body
e. Size of the person
f. All of the above
f. All of the above
Correct
Ground-fault circuit interrupters provide protection for persons.
True
A(n) ? is a device intended for the protection of personnel that functions to deenergize a circuit or portion thereof within an established period of time when a current to ground exceeds the values established for a Class A device.
Ground-fault Circuit Interrupter
The circuit-breaker types of GFCI open the entire branch circuit if a ground fault occurs, while outlet types only open a portion of the circuit.
True
A ground-fault circuit interrupter operates simply by measuring the current in the supply and return current-carrying conductors of the circuit and by monitoring for an imbalance that exceeds ? .
4 to 6 mA
A non–grounding-type receptacle is permitted to be replaced with another non–grounding-type receptacle where no grounding means exists in the outlet.
True
? is defined as a system intended to provide protection of equipment from damaging line-to-ground fault currents by operating to cause a disconnecting means to open all ungrounded conductors of the faulted circuit.
Ground-fault protection of equipment
Which of the following are common methods of grounding systems over 1,000 volts?
a. Grounded through an impedance device
b. Grounded through a set of grounding transformers
c. Solidly grounded I
d. All of the above
d. All of the above
Correct
Which of the following are the primary purposes of shielding for medium- and high-voltage cables?
a. To carry the ground-fault current to facilitate operation of ground-fault protective devices in the event of an electrical cable fault
b. To confine the voltage stresses to the insulation
c. To dissipate insulation leakage current
d. To drain off the capacitive charging current
e. All of the above
e. All of the above
Correct
All metallic shields (ribbon tape shields or concentric stranding) are required to be directly connected to which of the following?
I. A grounding busbar II. A grounding electrode III. A grounding electrode conductor IV. An equipment grounding conductor V. A neutral conductor VI. An ungrounded phase conductor
a. I., II., III., and IV. Correct
Note: The question seeks the Code answer. While the neutral may be connected to any of the conductors in choices a., b., c., or d., the NEC does specify the connection locations, and the neutral of a grounded or ungrounded system is not provided. See NEC 310.10(E).
The correct answer is: I., II., III., and IV.
