Final Exam 2 for 2020 Master Electrician

Fill in the blank:

For individual dwelling units with single-phase, 120/240-volt electrical systems of not over 400 amperes, the NEC® permits the service conductors to have an ampacity not less than ________ of the service ampere rating.

83%

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Fill in the blank:

Where multiple driven ground rods, driven pipes or buried plate grounding electrodes are installed to meet the rules set forth by the NEC®, the electrodes shall not be spaced less than ________ apart.

6 feet

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Fill in the blank:

When an ac general-use snap switch is used as a controller for a single-phase, 2 hp, 240-volt, ac motor, the switch is required to have an ampere rating of at LEAST ________.

15 amperes

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Fill in the blank:

Conductors shall be permitted to be tapped to feeder conductors without overcurrent protection at the tap where the length of the tap conductors does not exceed 25 feet. However, the tap conductors are to have an ampacity of not less than ________ of the ampacity of the feeder conductors to which they are tapped.

one-third

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Fill in the blanks:

Luminaires are permitted to be supported by framing members of suspended ceilings when securely fastened to the ceiling framing members by mechanical means such as ________, ________, and ________.

screws, rivets, listed clips

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Which of the following listed is not a requirement for an intersystem bonding termination?

a. Consist of not less than three (3) terminals.
b. Connected to the meter enclosure only with a minimum size 8 AWG conductor.
c. Terminals shall be listed for grounding and bonding.
d. Be accessible for connection and inspection.

b. Connected to the meter enclosure only with a minimum size 8 AWG
conductor.

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Fill in the blank:

Polyvinyl chloride conduit (PVC) larger than trade size ________ shall not be used.

6 in.

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Fill in the blank:

Nonmetallic sheathed cable, Type NM, is permitted to enter the top of surface-mounted cabinets and boxes through non flexible raceways of not less than 18 inches in length and not more than ________ in length, provided all the mandated conditions are met.

ten feet

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Flat cable assemblies (Type FC) shall be permitted for use as:

branch circuits not exceeding 30 amperes.

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Fill in the blank:

As a general NEC® rule, where a building or structure is supplied with a 3-phase, 480Y/277-volt electrical system, each disconnecting means rated at LEAST ________ or more shall be provided with ground-fault protection.

1,000 amperes

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Fill in the blank:

Power-limited fire alarm (PLFA) circuit conductors shall be protected from physical damage up to ________ above the floor when passing through a floor or wall.

7 feet

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Fill in the blank:

A fused disconnecting means for a 3-phase, 480-volt motor shall have an ampere rating of not less than ________ of the full-load current rating of the motor.

115 percent

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Fill in the blank:

A MINIMUM separation between heating elements of electric space-heating cables installed in ceilings and the edge of outlet boxes and junction boxes used for surface-mounted luminaires shall not be less than ________.

8 in.

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Where multiple driven ground rod electrodes make up the entire grounding electrode system for a building or structure having a 480Y/277-volt, 1,200 ampere rated service, what is the MINIMUM size copper conductor required to bond the ground rods together?

6 AWG

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Fill in the blank:

Where conduits or other raceways enter floor-standing switchboards, panelboards or switchgear from the bottom, the conduits or raceways, including their end fittings, shall not rise more than ________ above the bottom of the enclosure.

3 in.

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True or False:

The emergency shut-off device for gasoline motor fuel dispensers must simultaneously disconnect all grounded conductors of the circuit and ungrounded conductors, if any, from the source of supply.

TRUE

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In motion picture studios, television studios and similar locations, each receptacle of dc plugging boxes shall be rated not less than how many amperes?

30 amperes

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Fill in the blank:

Where sizes 1/0 AWG through 4/0 AWG single conductor cables are installed in ladder type cable tray, the MAXIMUM allowable rung spacing for the ladder type cable tray shall be ________.

9 in.

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Fill in the blank:

Type UF cable is not permitted to be used ________.

as service-entrance conductors

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Fill in the blank:

When applying the general method of calculations for dwelling units, the permitted demand factor, in percent, on the feeder and service conductors for five (5) household clothes dryers is ________.

85%

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Fill in the blank:

Where installed in commercial occupancies or industrial facilities, the MINIMUM height (headroom) of working spaces about service equipment, switchboards, switchgear, panelboards, motor control centers and similar equipment of 1000-volts or less is ________ or the height of the equipment, whichever is greater.

78 in.

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Fill in the blank:

As per the NEC®, plate grounding electrodes shall be installed not less than ________ below the surface of the earth.

30 in.

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Fill in the blank:

Size 14 AWG branch circuit tap conductors that serve individual outlets other than receptacles, are permitted to be tapped from 20-ampere rated branch circuit conductors when the ________.

size 14 AWG conductor length is not more than 18 inches

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Fill in the blank:

The branch-circuit, short-circuit and ground-fault protection for a hermetic motor-compressor shall have a rating or setting not exceeding ________ of the motor-compressor rated-load current or branch-circuit selection, whichever is greater, where the protection specified is sufficient for the starting current of the motor and modifications are not necessary.

175 percent

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# Fill in the blank: Where an electrical equipment room houses large equipment that contains overcurrent protective devices or switching devices, and the equipment is 1000-volts or less, rated 1,200-amperes or more and over 6 feet wide, for the purposes of entering and exiting the working space, two (2) entrances are required, one at each end. The doors are required to be not less than 6½ ft. high and not less than \_\_\_\_\_\_\_\_ wide.

2 ft.

Given: A trade size 1 in. Schedule 40 PVC conduit is run horizontally out of the side of a panelboard for 50 feet, then turns at a 90° angle vertically for 40 feet where it enters the building through a LB conduit body. How many expansion fittings are required for this installation?

two

# Fill in the blank: As a general rule, luminaires and lampholders shall have no live parts exposed to contact, an exception to this rule is where cleat-type lampholders are located at LEAST \_\_\_\_\_\_\_\_ or more above the floor, they shall be permitted to have exposed terminals.

8 feet

What MINIMUM size 75°C copper feeder conductors are required to supply the following listed 3-phase, 230-volt, continuous-duty, ac motors? * one (1) 15 hp wound-rotor * one (1) 7½ hp induction-type

4 AWG THWN

# Fill in the blank: AC or DC general-use snap switches may be used for control of inductive loads not exceeding \_\_\_\_\_\_\_\_ of the ampere rating of the switch at the applied voltage.

50%

# Fill in the blank: In general, cables or raceways shall be permitted to be laid in notches of wooden studs where the cable or raceway at those points is protected by a steel plate at LEAST \_\_\_\_\_\_\_\_ thick to cover the area of the wiring.

1/16 in.

Given: A service for a commercial occupancy will be supplied with three (3) size 300 kcmil copper conductors paralleled per phase. What is the MAXIMUM standard size overcurrent permitted for the paralleled service-entrance conductors where all the termination lugs are rated 75°C?

800 amperes

In an agricultural building, to what must the equipotential plane be bonded according to the NEC®?

* all metal structures * the electrical grounding system * fixed nonelectrical metal equipment that may become energized

# Fill in the blank: The NEC® recommended MAXIMUM total voltage drop on both feeders and branch circuit conductors is \_\_\_\_\_\_\_\_.

5 percent

# Fill in the blank: For other than single-family dwellings, an emergency disconnect switch must be provided for spas and hot tubs not less than \_\_\_\_\_\_\_\_ away from the spa or hot tub and must be readily accessible to the users.

5 feet

# Fill in the blank: When normal power is lost, legally required standby systems must be able to supply standby power in at LEAST \_\_\_\_\_\_\_\_ or less.

60 seconds

# Fill in the blank: Where conduit or tubing nipples having a length not to exceed 24 inches are installed between boxes, cabinets and similar enclosures, the nipples shall be permitted to be filled not to exceed \_\_\_\_\_\_\_\_ of their total cross-sectional area.

60%

# Fill in the blank: Receptacles supplying power to freestanding-type office furnishings shall not be more than \_\_\_\_\_\_\_\_ from the furnishing that it is connected to it.

1 foot

# Fill in the blank: A type of fuse not permitted for new installations and shall be used only for replacements in existing installations is a/n \_\_\_\_\_\_\_\_ fuse.

Edison-base

Given: A 10-unit multifamily dwelling with a 120/240-volt, single-phase electrical system will be provided with a 7.5 kW electric range in each dwelling unit. Apply the general method of calculations for dwelling occupancies and determine the demand load, in kW, on the ungrounded (line) service-entrance conductors.

25.5 kW

# Fill in the blank: Given: A 120/240-volt, single-phase service has a metal chain link fence opposite exposed live parts of the service equipment. The required depth of clear working space in front of the service equipment must be at LEAST \_\_\_\_\_\_\_\_.

3 ft.

When are remote disconnecting controls not required for critical operations data systems?

When an approved fire suppression system suitable for the application and a smoke-sensing fire detection system are in place.

Given: A retail jewelry store has two (2) large show windows having a length of 15 feet each. One show window is on each side of the entry door. How many single-phase, 125-volt, 15- or 20-ampere rated receptacles must be provided for the show window lighting?

two per window

# Fill in the blank: All emergency systems switchboards and panelboards shall be provided with \_\_\_\_\_\_\_\_ protection.

surge

What is the MINIMUM wire bending space required at the top and bottom of a panelboard that has one (1) size 3/0 AWG conductor connected to each busbar in the panelboard?

61⁄2 in.

# Fill in the blank: Given: A six (6) foot high chain-link fence topped with razor-wire, used to deter access by persons who are not qualified, encloses an outdoor installation of electrical apparatus rated 12 kV. The razor-wire shall be at LEAST \_\_\_\_\_\_\_\_ in height to comply with the NEC® standards.

12 in.

# Fill in the blank: When used as service entrance conductors, size 250 kcmil Type IGS cable has an ampacity of \_\_\_\_\_\_\_\_.

119 amperes

# Fill in the blank: Where a fused disconnect switch is used as the disconnecting means for an air-conditioning unit, the disconnect switch shall have an ampere rating of at LEAST \_\_\_\_\_\_\_\_ of the nameplate rated-load current of the equipment or branch-circuit selection current, whichever is greater.

115%

# Fill in the blank: Metal plugs or plates used to close unused openings in non metallic enclosures shall be recessed at LEAST \_\_\_\_\_\_\_\_ from the outer surface of the enclosure.

1/4 in.

# Fill in the blank: In the bedroom of a residence, any wall space having a width of \_\_\_\_\_\_\_\_ or more (including space measured around corners) and unbroken along the floor line by doorways or similar openings or fixed obstructions shall have a 125-volt, 15- or 20-ampere receptacle installed.

2 feet

# Fill in the blank: As a general rule, cables and conductors of Class 2 and Class 3 circuits shall not be placed in any \_\_\_\_\_\_\_\_ with the conductors of electric light and power circuit conductors unless, they are separated by a barrier.

device box, cable tray or manhole

Given: An induction-type, 3-phase, continuous-duty, ac motor has the following related information marked on the nameplate: FLA -54 amperes Temperature rise - 50°C Your task is to select the MAXIMUM size overload devices, in amperes, that is responsive to motor to protect the motor from overload. Assume the value you select will allow the motor and start without tripping and modification of this value is not necessary.

62.1 amperes

# Fill in the blank: The connection between the grounded circuit conductor and the equipment grounding conductor or the supply-side bonding jumper at the electrical service is recognized as the \_\_\_\_\_\_\_\_ in the NEC®.

main bonding jumper

# Fill in the blank: In guest rooms and guest suites of hotels and motels, at LEAST \_\_\_\_\_\_\_\_ 125-volt, single-phase, 15- or 20-ampere receptacle(s) is/are required to be readily accessible.

two

# Fill in the blank: Where a 225-ampere rated panelboard is equipped with snap switches rated for 30-amperes or less, the MAXIMUM overcurrent protection permitted for the panelboard has a rating of \_\_\_\_\_\_\_\_.

200 amperes

# Fill in the blank: Given: A 3-phase, 480-volt, squirrel-cage, Design B, 50 hp motor has a nameplate FLA rating of 59 amperes. The MAXIMUM initial standard size non-time delay fuses permitted for use as branch-circuit, short-circuit and ground-fault protective devices for the motor is \_\_\_\_\_\_\_\_.

200 amperes

# Fill in the blank: As a general rule, all fixed metal parts such as metal piping, metal fences, and metal awnings in the proximity of a permanently installed swimming pool are required to be bonded. An exception to this rule is when the metal parts are located at a horizontal distance at least greater than \_\_\_\_\_\_\_\_ from the inside walls of the pool they shall not be required to be bonded to the equipotential bonding grid.

5 feet

# Fill in the blank: The rating of a cord-and-plug connected room air-conditioner unit shall not exceed \_\_\_\_\_\_\_\_ where the unit is connected to a single receptacle supplied by a 30-ampere dedicated branch circuit.

24 amperes

# Fill in the blank: When exceptions are not a consideration, when attached to a building, final spans of outside overhead conductors, not over 1,000 volts, shall have a clearance of not less than \_\_\_\_\_\_\_ from windows designed to be opened, doors, porches balconies, stairs and fire escapes.

3 feet

# Fill in the blank: As a general NEC® rule, The MINIMUM size grounded or ungrounded copper or aluminum conductors permitted to be connected in parallel (electrically joined at both ends) is \_\_\_\_\_\_\_\_.

1/0AWG

# Fill in the blank: Legally required standby luminaires (unit equipment), provided for legally required standby illumination systems are to be permanently fixed in place however, they are permitted to be cord-and-plug connected provided the flexible cord does not exceed \_\_\_\_\_\_\_\_ in length.

3 feet

# Fill in the blank: In regard to electrified track parking spaces, upon loss of the normal power from the local utility company or other electric supply systems, means shall be provided where energy \_\_\_\_\_\_\_\_.

cannot be back-fed through the truck supply equipment

# Fill in the blank: According to the NEC®, handholes in metal or nonmetallic poles supporting luminaires shall not be required for poles \_\_\_\_\_\_\_\_ or less in height above finished grade, if the pole is provided with a hinged base.

20 feet

# Fill in the blank: What MINIMUM size 75°C copper feeder conductors are required to supply the following listed 3-phase, 230-volt, continuous-duty, ac motors? * one (1) 15 hp wound-rotor * one (1) 7½ hp induction-type

37.5 cubic in.

# Fill in the blank: A hazardous location where flammable gases, flammable vapors, or combustible liquid-produced vapors may be present in the air in quantities sufficient to produce explosive or ignitible mixtures, is a \_\_\_\_\_\_\_\_ location.

Class I

Determine the MAXIMUM standard size overcurrent protection permitted for a 480-volt transformer having primary full-load current rating of 40 amperes where primary protection only is required.

50 amperes

# Fill in the blank: All single-phase, 120-volt, 15- and 20-ampere branch circuits supplying outlets or devices installed in residential kitchens or similar rooms shall be protected by a listed arc-fault circuit-interrupter of the \_\_\_\_\_\_\_\_ type.

combination

# Fill in the blank: Outdoor installed spas and hot tubs are permitted to be cord-and-plug connected with a flexible cord not longer than \_\_\_\_\_\_\_\_ where protected by a ground-fault circuit interrupter.

15 feet

# Fill in the blank: Luminaires installed in fountains shall be protected by a ground-fault circuit interrupter and operate at a voltage not to exceed \_\_\_\_\_\_\_\_ between conductors.

150 volts

Which of the following is not required to be marked on the nameplate of a motor? a. manufacturer’s name b. full-load current c. rated temperature rise d. overcurrent protection

d. overcurrent protection

What MINIMUM size ungrounded (phase) THWN copper service entrance conductors are required for a 208Y/120-volt, 3-phase commercial service with a demand load of 72,000 VA?

3/0 AWG

Refer to the previous question and determine the required trade size of rigid metal conduit (RMC) for use as a service riser to enclose the conductors.

2 in.

# Fill in the blank: The ampacity adjustment factors shown in Table 310.15(C)(1), shall only be required to be applied to conductors in a metal wireway, where the number of current-carrying conductors exceeds \_\_\_\_\_\_\_\_ at any cross-section of the wireway.

How must every panelboard circuit and any circuit modifications be identified?

legibly identified at the panelboard to its specific purpose or use.

# Fill in the blank: Where a vertical raceway contains three (3) size 3/0 AWG copper conductors, the conductors shall be supported at intervals not greater than \_\_\_\_\_\_\_\_ with an additional support at the top of the conduit run.

80 feet

# Fill in the blank: In general, flat-top underfloor raceways of not over 4 in. wide shall have a covering of wood or concrete not less than \_\_\_\_\_\_\_\_ above the raceway.

3/4 in.

# Fill in the blank: Branch circuit conductors within 3 inches of a ballast of a fluorescent or HID luminaire shall have an insulation temperature rating of not less than \_\_\_\_\_\_\_\_, unless supplying a luminaire marked as suitable for a different insulation temperature.

90°C

# Fill in the blank: Strut-type channel raceways are permitted to be suspension mounted in air with identified methods at intervals not to exceed \_\_\_\_\_\_\_\_ and within \_\_\_\_\_\_\_\_ of the channel raceway ends.

10 ft., 3 ft.

# Fill in the blank: All 15- and 20-ampere, 125-volt and 250-volt non locking receptacles located in damp or wet locations shall be a listed \_\_\_\_\_\_\_\_ type.

weather-resistant

# Fill in the blank: In the lubrication pit area of a minor repair commercial garage where ventilation is not provided, the pit below floor level shall be a \_\_\_\_\_\_\_\_ location that extends up to the floor level.

Class I, Division 2

What is the MAXIMUM number of times a grounding electrode conductor is permitted to be spliced by the use of split-bolt connectors?

none

What is the general lighting demand load on the ungrounded (phase) conductors, in VA, of an industrial commercial (loft) building having dimensions of 100 ft. by 300 ft.

66,000 VA

# Fill in the blank: In the critical care (Category 1) spaces of health care facilities, a patient care vicinity shall be permitted to have an optional patient equipment grounding point. An equipment bonding jumper not small than \_\_\_\_\_\_\_\_ shall be used to connect the grounding terminal of all grounding-type receptacles to the patient equipment grounding point.

10 AWG

Given: Type UF cable is to be used for direct buried residential branch circuits of 120-volts. The conductors are GFCI protected and overcurrent protection is rated 20-amperes; the UF cable does not cross under any driveways or concrete. What is the MINIMUM required burial depth of the cable?

12 in.

# Fill in the blank: Disregarding exceptions,\_\_\_\_\_\_\_\_ is not permitted to be installed in theaters and similar locations unless it is encased in concrete.

Schedule 40 rigid PVC conduit

When a 240-volt, single-phase residential branch circuit using copper Type NM cable is used to supply an 8 kW rated counter-mounted cooking unit and a wall-mounted oven rated 6 kW, what MINIMUM size NM cable is required?

8/3 AWG with ground

A storage area where flammable liquids are stored in closed containers is classified as what type of hazardous location?

Class I, Division 2

What is the MAXIMUM number of size 4 AWG THHN copper conductors permitted by the NEC® that may be installed in a trade size 1¼ in. electrical metallic tubing (EMT) 18-inch long nipple?

# Fill in the blank: Luminaires installed over highly combustible material shall be of the \_\_\_\_\_\_\_\_ type and located 8 ft. above the floor or guarded.

unswitched

# Fill in the blank: When a rigid metal conduit (RMC) run leaves a Class I, Division 1 hazardous location a conduit sealing fitting must be installed to prevent the transmission of hazardous gasses or vapors. The conduit seal should be installed \_\_\_\_\_\_\_\_.

within 10 ft. on either side of the boundary of the Class I, Division 1 area

# Fill in the blank: When doing conduit fill calculations, for cables that have elliptical cross-sections, the cross-sectional area calculation shall be based on using the \_\_\_\_\_\_\_\_ diameter ellipse as a circular diameter.

major

# Fill in the blank: Where circuit breakers are used as switches in 120-volt and 277-volt fluorescent lighting circuits they shall be listed and marked with \_\_\_\_\_\_\_\_ on the circuit breaker. I. SWD II. HID

either I or II

Determine the MINIMUM number of 120-volt, 15-ampere general-lighting branch circuits required for a 15,000 sq. ft. multifamily dwelling unit.

# Fill in the blank: Wiring located above heated ceilings shall be spaced at not less than 2 inches above the heated ceiling and shall be considered as operating at an assumed ambient temperature of \_\_\_\_\_\_\_\_.

50°C

# Fill in the blank: Unless listed for a higher voltage, surface nonmetallic raceways are not approved where the voltage is \_\_\_\_\_\_\_\_ or more between conductors.

300 volts

# Fill in the blank: At marinas and boatyards, the electrical datum plane, in land areas subject to tidal fluctuation, is a horizontal plane \_\_\_\_\_\_\_\_ above the highest high tide under normal circumstances.

2 feet

Given: A feeder circuit using aluminum conductors is installed in PVC conduit and protected by a 500-ampere rated circuit breaker. What is the MINIMUM size aluminum conductor permitted for use as the equipment grounding conductor.

1/0 AWG

# Fill in the blank: Bends in liquidtight flexible nonmetallic conduit (LFNC) shall be made so that the conduit will not be damaged and the internal diameter of the conduit will not be reduced. Bends are permitted to be made \_\_\_\_\_\_\_\_.

manually without auxiliary equipment

Where should the remote disconnect controls be located in an information technology equipment room housing electronic computer or data processing equipment? They must be at readily accessible approved locations in case of fire.

at readily accessible approved locations in case of fire.

# Fill in the blank: When size 500 kcmil copper conductors with THWN insulation are used as service entrance conductors, the MAXIMUM standard size circuit breaker permitted for use as overcurrent protection has a rating of \_\_\_\_\_\_\_\_.

400 amperes

# Fill in the blank: The disconnecting means for transport refrigerated units (TRUs) located in electrified truck parking spaces of a truck plaza, shall be readily accessible and not more than \_\_\_\_\_\_\_\_ from the receptacle it controls.

30 in.

Final Exam 2 Flashcards

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