Final Exam 2 for 2023 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%

How well did you know this?

Not at all

Perfectly

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

How well did you know this?

Not at all

Perfectly

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

15 Ampere switch x 80% = 12 amperes
FLC of motor – 12 amperes x 125% = 15 amperes

How well did you know this?

Not at all

Perfectly

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

How well did you know this?

Not at all

Perfectly

Fill in the blank:

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

How well did you know this?

Not at all

Perfectly

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.

How well did you know this?

Not at all

Perfectly

Fill in the blank:

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

6 in.

How well did you know this?

Not at all

Perfectly

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

How well did you know this?

Not at all

Perfectly

Fill in the blank:

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

branch circuits not exceeding 30 amperes.

How well did you know this?

Not at all

Perfectly

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

How well did you know this?

Not at all

Perfectly

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

How well did you know this?

Not at all

Perfectly

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%

How well did you know this?

Not at all

Perfectly

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.

How well did you know this?

Not at all

Perfectly

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 wire-type copper conductor required to bond the ground rods together?

6 AWG

How well did you know this?

Not at all

Perfectly

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.

How well did you know this?

Not at all

Perfectly

Which of the following statements about the emergency shut-off device provided for gasoline motor fuel dispensers is true?

a.It must simultaneously disconnect all grounded conductors of the circuit, and ungrounded conductors, if any, from the source of supply.
b.It must be a 2-pole circuit breaker.
c.It must be located at least 6 ft. above final grade.
d.All of these statements are true.

a. It must simultaneously disconnect all grounded conductors of the circuit, and ungrounded conductors, if any, from the source of supply.

How well did you know this?

Not at all

Perfectly

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

How well did you know this?

Not at all

Perfectly

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.

How well did you know this?

Not at all

Perfectly

Fill in the blank:

Type UF cable is not permitted to be used as _________.

service-entrance conductors

How well did you know this?

Not at all

Perfectly

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%

How well did you know this?

Not at all

Perfectly

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.

How well did you know this?

Not at all

Perfectly

Fill in the blank:

As required by the NEC®, plate grounding electrodes shall be installed not less than _________ below the surface of the earth.

30 in.

How well did you know this?

Not at all

Perfectly

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 in.

How well did you know this?

Not at all

Perfectly

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%

How well did you know this?

Not at all

Perfectly

# Fill in the blank: The Code mandates 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 at least over \_\_\_\_\_\_\_\_\_ wide or more, 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 2 feet wide.

4 feet

What is the calculated demand load, in kW, on the service and feeder ungrounded conductors for four (4) household electric ranges rated at 4.5kW, 5 kW, 8.5 kW, and 5 kW?

11.50 kW ## Footnote 4.5 kW + 5 kW + 8.5 kW + 5 kW + 23 kW 23 kW x 50% (column B, 4 ranges) = 11.5 kW

# Fill in the blank: As a general rule, luminaires and lamp holders 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, 240-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

# Fill in the blank: Receptacles rated 125-volts through 250-volts, 60-amperes or less,within \_\_\_\_\_\_\_\_\_ of the inside wall of a permanently installed swimming pool must be provided with GFCI protection.

20 feet

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

# Fill in the blank: For other than one-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 nipplesshall 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.

# Fill in the blank: When are remote disconnecting controls not required for critical operations data systems?

* an approved fire suppression system suitable for the application is in place * wiring is under raised floors

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?

6½ 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 atleast \_\_\_\_\_\_\_\_\_ 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 \_\_\_\_\_\_\_\_\_, \_\_\_\_\_\_\_\_\_, or \_\_\_\_\_\_\_\_\_ with the conductors of electric light and power circuit conductors unless, they are separated by a barrier.

device box, cable tray, 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 - 44°C Your task is to select the required 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 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 attached to a building, final spans of outside overhead conductors,not over 1,000 volts, shall have a horizontal 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 \_\_\_\_\_\_\_\_\_.

1/0 AWG

# Fill in the blank: The service equipment for a marina shall be located on land no closerthan \_\_\_\_\_\_\_\_\_ horizontally from and adjacent to the structure served.

5 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: Given: A junction box with a flat blank cover and no internal clamps will contain the following conductors: * six – size 14 AWG THHN * eight – size 12 THWN * three – size 10 THW The junction box is required to have a volume, in cubic inches, of \_\_\_\_\_\_\_\_\_.

37.5 cubic in. ## Footnote Size 14 AWG – 6 wires x 2.00 cu. in. = 12.0 cu. in. Size 12 AWG - 8 wires x 2.25 cu. in. = 18.0 cu. in. Size 10 AWG - 3 wires x 2.50 cu. in. = 7.5 cu. in. Total = 37.5 Cu. 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

What information is not required to be marked on a motor's nameplate?

overcurrent protection

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

3/0 AWG ## Footnote I = P ÷ E x 1.732 I = 72,000 VA/208 x 1.732 = 72,000/360.25 = 199.8 amperes Size 3/0 AWG THWN cu conductors with an ampacity of 200 amperes should be selected from Table 310.16.

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 circuit modification be identified or marked?

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: For new installations in residential outdoor areas where permanently installed swimming pools are located, ceiling-suspended (paddle) fans installed above the pool or the area extending 5 feet horizontally from the inside walls of the pool, shall be installed at a height of not less than \_\_\_\_\_\_\_\_\_ above the maximum water level of the swimming pool.

90°C

# Fill in the blank: Strut-type channel raceways are permitted to be suspension mounted inair 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 ## Footnote 100 ft. x 300 ft. = 30,000 sq. ft. x 2.2 VA = 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 smaller 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 a driveway or concrete. What is the minimum required burial depth of the cable?

12 in.

# Fill in the blank: In theaters and similar locations, \_\_\_\_\_\_\_\_\_ is not permitted to be installed 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 unitand a wall-mounted oven rated 6 kW, what minimum size NM cable isrequired?

8/3 AWG with ground ## Footnote 8 kW + 6 kW = 14 kW (treat as one range) 14 kW – 12 kW = 2 kW x 5% = 10% increase in column C 8 kW (column C) x 110% = 8.8 kW I = P ÷ E I = 8.8 kW x 1000/240 volts = 8800/240 = 36.7 amperes Size 8 AWG NM cable with an ampacity of 40 amperes should be selected from the 60°C column of Table 310.16.

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: Given: 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

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

25 ## Footnote 15,000 sq. ft. x 3 VA = 45,000 VA (load) 120 volts x 15 amperes = 1,800 VA (one circuit) 45,000 VA (load)/1,800 VA (1 ckt.) = 25 (15 ampere general lighting circuits)

# 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, inland 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 wire-type conductor permitted for use as the equipment grounding conductor?

1/0 AWG

Where a 120-volt, single-phase branch circuit using 10 AWG copper conductors is supplying a sign with a 16-ampere load, located 100 ft. from the panelboard, determine the approximate voltage drop. (K = 12.9)

5.16 volts

Where should the remote disconnect controls for electronic computer/data processing equipment and HVAC systems be located in an information technology equipment room?

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

Confirm mastery of NEC 2023 concepts, simulate the real Master Electrician exam, and finalize preparation strategies. (100 cards)