3rd year final

Réussis tes devoirs et examens dès maintenant avec Quizwiz!

Where supplementary overcurrent protection is used for luminaires, appliances, and other equipment or for internal circuits and components of equipment, it shall be permitted to serve as a substitute for required branch-circuit overcurrent devices or in place of the required branch-circuit protection. a. True b. False NEC Reference Answer:

false 240.10

identify seale pattern

large wires on outside small wires on inside

An approach limit at a distance from an exposed energized electrical conductor or circuit part within which a shock hazard exists

limited approach boundary

. Safety factor is the ratio of a components breaking strength to its rated ___. Load Swing Safety factor Breaking strength

load

Informational Note No. 2 located after Table 130.5(C) provides the rationale that improper or inadequate maintenance may result in the protecting-OCPD taking longer to clear the fault current than its specified published clearing time. Select one: True False

true

. The 1995 edition of NFPA 70E included the concepts of ? and the establishment of an arc. The 2000 edition continued to focus on establishment of flash protection boundaries, the use of personal protective equipment, and ? to assist the user in applying appropriate protective clothing and personal protective equipment for common tasks. Select one: a. electrical protection / recommendations b. GFCI / guidance c. limits of approach / charts d. short circuit calculations / load calculations

c. limits of approach/charts

Separate motor and branch-circuit overload protection is sized based upon the _?_ . a. Full load current based on motor horsepower in NEC Tables 430.247 to 430.250 b. maximum locked-rotor current c. motor nameplate full-load current d. start-up current NEC Reference Answer:

c. motor nameplate full-load current 430.6 (A)(2)

Which part of Article 250 provides the requirements for grounding electrodes and the grounding electrode system? Select one: a. Part I b. Part II c. Part III d. Part IV

c. part III

Fuses and circuit breakers are required to be marked with all but which of the following? Select one: a. Ampere interrupting current rating (AIC) b. Normal current rating c. Resistance d. voltage

c. resistance

Which of the following is not permitted as a grounding electrode? Select one: a. Concrete footings b. Structural steel in contact with the earth for not less than 10' c. Underground metal gas piping d. Underground water pipe

c. underground metal gas piping

type V sling

continuous loop, endless sling, grommet

Medium- and high-voltage cables above ? are generally required to be shielded, and this shielding is usually in the form of either a conductive tape or stranded conductors. Select one: a. 150 V b. 600 V c. 1,000 V d. 2,000 V

d. 2,000 V

In some cases, momentary high inrush currents during motor starting can reach as high as _?_ times the normal running current amperes during the first 1/2 cycle. Select one: a. 2 b. 4 c. 10 d. 20

d. 20

NEC Table _?_ is required to be used for minimum sizing of equipment grounding conductors for branch circuits and feeders. Select one: a. 250.4 b. 250.66 c. 250.102(C)(1) d. 250.122

d. 250.122

The maximum delay (retard) for a waterflow switch is _?_ . Select one: a. 30 seconds b. 45 seconds c. 60 seconds d. 90 seconds

d. 90 seconds

What Annex in NFPA 70E provides information on various calculation methods to determine the AFB and incident energy? Select one: a. A b. B c. C d. D e. E

d. D

Which of the following are required to be included on an energized electrical work permit? I. Date of the most recent calibration of the upstream overcurrent protective device protecting the circuit II. Documentation of the arc flash risk assessment method used III. Justification for why the work must be performed in an energized condition IV. Personal and other protective equipment required by NFPA 70E to safely perform the assigned task and to protect against the shock hazard V. Results of the arc flash risk assessment Select one: a. I., II., III., IV., and V. b. I., III., and V. c. II., III., and IV. d. III., IV., and V.

d. III,IV, and V

Which of the following can be thought of as the foundation of an electrical system? Select one: a. The electrical service equipment b. The equipment grounding conductor c. The grounding electrode conductor d. The grounding electrode system

d. The grounding electrode system

. A duct smoke detector actuation is permitted to cause a(n) _?_ . Select one: a. alarm signal b. supervisory signal at a constantly attended location c. trouble signal at a constantly attended location d. a. and b. only

d. a and b only

If present, which of the following grounding electrodes must be used to form a grounding electrode system for a building or structure served by a feeder or branch circuit? Select one: a. Ground rods b. Metal in-ground support structures c. Underground metal water pipe d. All of the above must be used

d. all of the above must be used

. Mechanical covers or protection for notification appliances may _?_ . Select one: a. reduce the effectiveness of the appliance b. require derating of the appliance c. require reduced spacing of the appliances d. all of the above

d. all the above

In addition to determining the proper OCPD ampere rating for an application, what criteria is/are important when selecting overcurrent devices? Select one: a. Interrupting rating b. Short-circuit current ratings c. Voltage rating d. All of the above

d. all the above

The ground fault protection system shall be performance tested when first installed on site. What else is required as part of this performance testing? a. 230.95(C) requires GFPE to be performance tested when installed using the primary current injection test process. b. A written record of this test must be available to the authority having jurisdiction. c. The test shall be conducted in accordance with instructions that are required to be provided with the equipment. d. All of the above. NEC Reference Answer:

d. all the above 230.95 (c)

The main bonding jumper in a service disconnecting means enclosure can be in which of the following forms? Select one: a. Bus b. Green screw c. Wire d. Any of the above

d. any of the above

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. Select one: a. arc-fault circuit interrupter b. circuit breaker c. current-limiting fuse d. ground-fault circuit interrupter

d. ground fault circuit interruptors

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. Select one: a. approved b. certified c. identified d. listed

d. listed

_?_ of Article 250 specifically applies to grounding systems and circuits over 1,000 volts. Select one: a. Part I b. Part V c. Part IX d. Part X

d. part x

Which of the following is not accomplished through electrical bonding? Select one: a. Conductivity b. Connecting together c. Continuity d. Providing overcurrent protection

d. providing overcurrent protection

The grounding electrode conductor for a separately derived system is required to be connected to the grounded conductor at the same location where the _?_ is installed. Select one: a. equipment bonding jumper b. first overcurrent device enclosure c. grounding electrode d. system bonding jumper

d. system bonding jumper

The maximum spacing of visible appliances used in a corridor is _?_ . Select one: a. 15' b. 30' c. 50' d. 100'

d.100'

Sound pressure level (SPL) is always measured using the _?_ scale. Select one: a. A-weighted b. B-weighted c. C-weighted d. D-weighted

a. a-weighted

For current to be present in electrical circuits, the circuit has to be ? . Select one: a. complete b. connected to earth c. single-phase d. 3-phase

a. complete

If the voltage of a DC circuit is 24 volts, and the resistance of the circuit is 10 ohms, what is the amount of current present in the circuit? Select one: a. 0.24 A b. 2.4 A c. 240 A d. 2400 A

b. 2.4 A

For a grounded service, the _?_ is the intentionally constructed, low-impedance, effective ground-fault current path addressed in 250.4(A). Select one: a. equipment grounding conductor b. grounded conductor c. system bonding jumper d. ungrounded conductor

b. grounded conductor

An in-building fire emergency voice/alarm communications system is usually found in a _?_ . Select one: a. dwelling b. high-rise building c. small office building d. warehouse

b. high rise buildings

The primary purpose of dwelling fire warning equipment or systems is _?_ . Select one: a. heritage protection b. life safety c. mission continuity d. property protection

b. life safety

Strobes must be synchronized when there are _?_ . Select one: a. ceiling-mounted appliances b. more than two appliances in a room c. multiple appliances that can be viewed from outdoors d. none of the above

b. more than two appliances in a room

a type of short circuit defined as an unintentional connection between an ungrounded conductor and ground, an equipment gorunding conductor, or grounded equipment is a a) current limiter b) ground conductor c) ground fault d) overload

c) ground fault

a __ is a current greater than the equipment rated current or conductor ampacity, which is confined to the normal conductive paths provided by the conductors and other equipment a) branch-circuit overcurrent device b) overcurrent c) overload d) supplementary overcurrent device

c) overload

A metal underground water pipe that is in direct contact with the Earth for _?_ or more is a Code-recognized as a grounding electrode and must be included in the grounding electrode system. Select one: a. 3' b. 5' c. 10' d. Any of the above

c. 10'

Rate-of-rise heat detectors usually operate when the temperature rise is _?_ per minute. Select one: a. 10-15° b. 10-20° c. 12-15° d. 15-20°

c. 12-15°

The bonding conductor or grounding electrode conductor for a communications system shall not be smaller than _?_ copper or other corrosion resistant material. Select one: a. 10 AWG b. 12 AWG c. 14 AWG d. 16 AWG

c. 14 AWG

. Waterflow switches are permitted to have a time delay, or retard, up to _?_ . Select one: a. 30 seconds b. 60 seconds c. 90 seconds d. 120 seconds

c. 90 seconds

If a motor nameplate shows a service factor of 115%, the motor is designed to operate at _?_ its rated horsepower. Select one: a. 1.15 times b. 0.115 times c. 115% d. both a. and c. e. none of the above

d both a and c

The ground-fault protection system must operate to cause the service disconnect to open all ungrounded conductors of the faulted circuit. The maximum setting of the ground-fault protection permitted is _?_ , and the maximum time-delay setting is _?_ for ground-fault currents equal to or greater than 3,000 amperes. Select one: a. 500 A / 1 second b. 1,000 A / 1 second c. 1,000 A / 3 seconds d. 1,200 A / 1 second

d. 1,200 A / 1 second

If a feeder supplied by a 4,160-volt system is protected at 400 amperes, what is the minimum-size aluminum equipment grounding conductor required for the circuit? Select one: a. 1 AWG b. 2 AWG c. 3 AWG d. 6 AWG

a. 1 AWG

The arc flash boundary shall be the distance at which the incident energy equals _?_ .

a. 1.2 cal/cm2

The system bonding jumper for a separately derived system has to be installed and sized in accordance with _?_ . Select one: a. 250.28(A) through (D) b. 250.122 c. NEC Table 8, Chapter 9 d. Table 310.15(B)(16)

a. 250.28(A) through (D)

A separately derived system is required to be grounded in accordance with 250.30(A), and it is located 50 feet from a building structural metal electrode and 100 feet from a metal water pipe electrode. Which of the following grounding electrodes is required to be used to meet the minimum requirements in the NEC? Select one: a. The system shall be grounded by connection to the building grounding electrode system. b. The system shall be grounded by connection only to the metal building frame electrode. c. The system shall be grounded to both the water pipe electrode and the metal building frame electrode. d. Any of the above

a. The system shall be grounded by connection to the building grounding electrode system.

The Underwriters Laboratories (UL) requirement for _?_ ground-fault circuit interrupters (GFCIs) is that tripping shall occur when the continuous 60-hertz differential current exceeds six milliamperes, but it shall not trip at less than four milliamperes. Select one: a. Class A b. Class B c. Class C d. Class D

a. class A

chapter 1 through 4 of the nec apply ___ a. generally b. only to special conditions c. only to special equipment d. only to special occupancies

a. generally

Notification appliances used outdoors may result in _?_ unless listed for such use. Select one: a. ground faults b. open circuits c. both a. and b. d. none of the above

a. ground faults

The highest current at rated voltage that a device is identified to interrupt under standard test conditions best defines which of the following? Select one: a. Interrupting rating b. Maximum impedance c. Maximum resistance d. Maximum voltage

a. interrupting rating

GFPE is required for a 1,000-ampere service disconnect with 800-ampere fuses for a 480/277-volt, 3-phase, 4-wire, solidly grounded wye electrical system. a. True b. False NEC Reference Answer:

a. true 230.95

The Informational Note to the definition of arc flash boundary states that, according to the Stoll skin burn injury model, the onset of a second degree burn on unprotected skin is likely to occur at an exposure of ? for one second. Select one: a. 1.2 cal/cm2 b. 2 cal/cm2 c. 4.8 cal/cm2 d. 5 cal/cm2

a.1.2 cal/cm2

When an arc flash hazard exists, an approach limit from an arc source at which incident energy equals 1.2 cal/cm2 (5 J/cm2 )

arc-flash boundary

what electrical circuit condition best describes a phase or ungrounded conductor that comes into contact with another phase conductor a) overload b) short circuit c) too many loads connected to a circuit d) ungrounded circuit

b) short circuit

The appointment of the NFPA 70E Committee was announced on January 7, _?_ , and was formed to assist _?_ in preparing electrical safety standards that would serve its requirements. Select one: a. 1970 / OSHA b. 1976 / OSHA c. 1981 / NFPA d. 1983 / NFPA

b. 1976/OSHA

. A rod or pipe electrode is generally required to be driven to a depth of not less than _?_ . Select one: a. 6' b. 8' c. 10' d. 12'

b. 8'

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 Select one: a. I., II., and V. b. I., II., III., and IV. c. II., IV., and VI. d. III., V., and VI.

b. I., II., III., and IV.

A smoke detector that has a laser particle counter is best suited for _?_ . Select one: a. attics b. clean rooms c. garages d. kitchens

b. clean rooms

An electrical hazard is defined as a dangerous condition such that contact or _?_ can result in electric shock, arc flash burn, thermal burn, or _?_ . Select one: a. approach / other electrically-related hazards b. equipment failure / arc blast injury c. exposure / other hazards d. working in the proximity / incurable burn

b. equipment failure/ arc blast injury

Ground-fault protection of equipment is not permitted for _?_ or required for a continuous industrial process where a non-orderly shutdown would introduce additional or increased hazards. a. electronically-actuated fuses b. fire pump circuits c. industrial buildings d. phase converters

b. fire pump circuits

If a conductive part is connected to ground or to a conductive body that extends a ground connection, it is _?_ . Select one: a. bonded b. grounded c. guarded d. protected

b. grounded

Which type of smoke detector works best in large open areas? Select one: a. Ionization-type b. Projected beam-type c. Spot-type d. All of the above

b. projected beam type

Supervising stations that only monitor property owned by the supervising station operator are called _?_ . Select one: a. central supervising stations b. proprietary supervising stations c. protected premises systems d. remote supervising stations

b. proprietary supervising stations

The time difference between the ceiling temperature and the sensing element reaching the same temperature is called _?_ . Select one: a. response time index b. thermal lag c. thermal response characteristic d. time-delay response

b. thermal leg

A ground-fault circuit interrupter operates by measuring the current in the supply and return current-carrying conductors of the circuit and by monitoring for an imbalance that exceeds _?_ to _?_ . Select one: a. 1 to 2 mA b. 3 to 5 mA c. 4 to 6 mA d. 20 to 30 mA

c. 4 to 6 mA

. A _?_ equipment grounding conductor is the minimum size required for a 1,000-ampere feeder supplying a separate building or structure. Select one: a. 1/0 AWG copper b. 2/0 AWG aluminum c. 4/0 AWG aluminum d. 3/0 AWG copper

c. 4/0 awg aluminum Table 250.122

Which of the following are required to be included on an energized electrical work permit? I. Arc flash boundary II. Available incident energy at the working distance or arc flash PPE category III. Name(s) of person(s) performing the arc flash risk assessment IV. Personal and other protective equipment required by NFPA 70E to protect against the arc flash hazard V. Results of the shock risk assessment Select one: a. I., II. III., and IV. b. I., II., III., IV., and V. c. I., II., IV., and V. d. I., III., and V.

c. I,II,IV, and V

. Electrical systems that are grounded shall be connected to earth to provide which of the following functions? I. Facilitate overcurrent device operation II. Limit line surges, or unintentional contact with lines of higher voltage III. Limit the voltage imposed by lightning IV. Stabilize voltages during normal operation Select one: a. I., II., and III. b. I., II., and IV. c. II., III., and IV. d. III., and IV. Only

c. II, III, and IV

Which of the following are required to be included on an energized electrical work permit? I. Date and duration of the permit II. Energized work approval signature(s) III. Evidence of completion of a job briefing, including a discussion of any job-specific hazards IV. Means employed to restrict the access of unqualified persons from the work area V. Name(s) of person(s) qualified to perform the task energized Select one: a. I., II., III., and IV. b. I., II., III., IV., and V. c. II., III., and IV. d. IV. and V.

c. II, III, and IV

If a main bonding jumper is a wire type, what NEC table is used to size it? Select one: a. Table 8, Chapter 9 b. Table 250.66 c. Table 250.102(C)(1) d. Table 250.122

c. Table 250.102 (C)(1)

. The term branch circuit has different meanings as used in the NEC. Which of the following statement(s) is/are correct? Select one: a. A branch circuit is a type of circuit in an electrical distribution system connected from the final OCPD to the outlets and is not limited to the type of wiring method used. b. A category of overcurrent protective device used for services, feeders, branch circuits and equipment providing a full range of protection against short circuits, ground faults and overloads. c. Both a. and b. are correct. d. Neither a. nor b. is correct.

c. both a and b are correct

Which of the following is a "fail-safe" circuit? Select one: a. Class B b. Class C c. Class D d. Class E

c. class D

Which of the following colors is not permitted to be used to identify a grounded conductor? Select one: a. Bare conductor of Type SEU cable b. Gray c. Green d. White

c. green

The _?_ provides the essential function of connecting the electrical system, equipment, or both to the earth. Select one: a. equipment grounding conductor b. grounded conductor c. grounding electrode d. main bonding jumper

c. grounding electrode

NFPA 70E, Standard for Electrical Safety in the Workplace, consists of _?_ chapters; 17 informative annexes; the Foreword to NFPA 70E; and Article 90, Introduction. Chapter 1 is divided into _?_ articles. Select one: a. 3 / 5 b. 3 / 7 c. 5 / 5 d. 5 / 7

a. 3/5

Which of the following are the primary purposes of shielding for medium- and high-voltage cables? Select one: 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

A grounded conductor (often the neutral) larger than 6 AWG is required to be identified by which of the following methods? Select one: a. A bare conductor that is part of a listed service-entrance cable assembly b. A continuous white or gray outer finish c. A distinctive white or gray marking at terminations that encircles the conductor d. Three continuous white or gray stripes along its entire length on other than green insulation e. Any of the above

e. any of the above

A frequent inspection is a thorough rigging inspection performed before the equipment in placed into service to ensure the equipment meets applicable government regulations and/or industry standards. true or false

false

If a feeder to a separate building or structure is installed in rigid metal conduit, the conduit is not permitted to serve as the required equipment grounding conductor. Select one: True False

false

Improperly grounding of neutral conductors has no effect on a GFPE to detect ground fault currents accurately. Select one: True False

false

The copper ribbon or tape shield of a medium-voltage cable is permitted to serve as the required equipment grounding conductor for a circuit supplied by a 1,500-volt, solidly grounded system. Select one: True False

false

When conducting an arc flash risk assessment in accordance with 130.5, the "condition of maintenance" is not a consideration. Select one: True False

false

An approach limit at a distance from an exposed energized electrical conductor or circuit part within which there is an increased likelihood of electric shock, due to electrical arc-over combined with inadvertent movement

restricted approach boundary

. Per NEC 240.21, overcurrent protection shall be provided in each ungrounded circuit conductor and shall be located at the point where the conductors receive their supply except as specified in 240.21(A) through (H). Select one: True False

true

A connection to ground through a grounding electrode system is generally required at separate buildings or structures to establish a reference to ground at that location. Select one: True False

true

An unqualified person is never permitted to cross the restricted approach boundary. Select one: True False

true

Both audible and visible appliances can be wired on the same circuit. Select one: True False

true

Section 250.50 requires all grounding electrodes that are present at each building or structure served to be bonded together to form the grounding electrode system. Select one: True False

true

The characteristic of the operating mechanism in using the handle to open or close a circuit breaker is referred to as quick-make, quick-break as to prevent the breaker from being able to be "teased" from OFF-to-ON or ON-to-OFF. Select one: True False

true

The operating mechanism, including the handle, opens or closes the circuit breaker contacts. Select one: True False

true

The purpose of the NEC is to provide electrical installation requirements that protect persons and property from electrical hazards arising from the use of electricity. Select one: True False

true

When an AC motor is started across the line, a high inrush current occurs. Select one: True False

true

Where equipment is not properly installed or maintained, PPE selection based on incident energy analysis or the PPE category method might not provide adequate protection from arc flash hazards. Select one: True False

true

ground fault circuit interruptors provide protection for persons true or false

true

if an electrical circuit is not complete it will have no current true or false

true

. A circuit breaker is a device designed to open and close a circuit by nonautomatic means and to open the circuit automatically on a predetermined overcurrent without damage to itself when properly applied within its rating. a. True b. False NEC Reference Answer:

true 100


Ensembles d'études connexes

COMPTIA A+ 220-902 - DOMAIN 3.0 - SECURITY

View Set

Exam #2 (Chp 6-10) - Organizational Behavior

View Set