2023 Commercial Electrical Inspector – Practice Quiz (Untimed)

2023 Commercial Electrical Inspector (Untimed)

80 Questions

3.5 Hours

1 / 80

1. The size of the DC system bonding jumper shall not be smaller than what conductor?

A) The system grounding electrode conductor specified in 250.166

B) The largest derived ungrounded conductor

C) The neutral conductor

D) 4 AWG copper

2 / 80

2. What term describes a building or portion thereof used on a 24-hour basis for the medical, psychiatric, obstetrical, or surgical care of four or more inpatients?

A) Nursing Home

B) Ambulatory Health Care Occupancy

C) Hospital

D) Limited Care Facility

3 / 80

3. In industrial installations only, secondary conductors not over 7.5 m (25 ft) long are permitted without protection at the secondary connection if the sum of the ratings of the overcurrent devices does not exceed what value?

A) 125 percent of the connected load

B) The secondary current rating of the transformer

C) The maximum connected load

D) 80 percent of the feeder conductor ampacity

4 / 80

4. How is the requirement for ground-fault protection of equipment determined for the overcurrent protection device of the Power Production Source service disconnecting means?

A) It is always required for systems over 150 volts to ground.

B) It is determined by the total available fault current.

C) It is based on the service conductor ampacity.

D) The rating of the overcurrent protection device of the power production source service disconnecting means shall be used to determine if ground-fault protection of equipment is required in accordance with 230.95.

5 / 80

5. The bottom of transformer enclosures installed in a marina shall not be located below what designated point?

A) 300 mm (12 in.) above the deck

B) The electrical datum plane

C) The highest high tide level

D) The pier deck surface

6 / 80

6. Other outlets not specifically covered in 220.14(A) through (J) shall be calculated based on how many volt-amperes per outlet?

A) 180 volt-amperes

B) 90 volt-amperes

C) 300 volt-amperes

D) 120 volt-amperes

7 / 80

7. The means of bonding to wire mesh or conductive elements of an equipotential plane in agricultural buildings must be by pressure connectors or clamps made of what materials, or other approved means?

A) Aluminum or galvanized steel

B) Steel or zinc

C) Brass, copper, copper alloy, or other approved means

D) Flexible metal conduit

8 / 80

8. Exposed elements of impedance heating systems must be protected against contact by personnel by being physically guarded, isolated, or thermally insulated with what component?

A) A weatherproof jacket

B) A metal screen

C) A nonmetallic enclosure

D) A glass fiber barrier

9 / 80

9. What type of battery must have insulating support if a voltage is present between the container and ground?

A) All lithium-ion batteries

B) Batteries constructed of plastic containers

C) Batteries constructed of an electrically conductive container

D) All valve-regulated lead-acid batteries

10 / 80

10. If the grounded conductor terminal in a polarized attachment plug is not visible, how shall the conductor entrance hole be identified?

A) Colored white or marked with the word "white" or the letter "W"

B) Colored blue or marked with the letter "B"

C) Engraved with a lightning bolt symbol

D) Marked with the word "neutral" or the letter "N"

11 / 80

11. Tap conductors supplying electric ranges from a branch circuit not exceeding 50 amperes must have an ampacity of not less than 20 amperes and shall not be longer than necessary for what purpose?

A) Conductor identification

B) Voltage drop compensation

C) Future load expansion

D) Servicing the appliance

12 / 80

12. If fused cutouts are not interlocked to prevent opening under load, what must be placed at such cutouts?

A) An operating instruction manual

B) A lockout/tagout procedure

C) A conspicuous sign identifying that they shall not be operated under load

D) A remote operation handle

13 / 80

13. Which type of backfed circuit breaker is permitted to omit the additional fastener normally required by 408.36(D)?

A) Circuit breakers where the line and load terminals are marked.

B) Listed plug-in-type circuit breakers backfed from electric power sources that are listed and identified as interactive.

C) Circuit breakers rated for 100% continuous duty.

D) Circuit breakers rated for reverse current.

14 / 80

14. EVSE shall have a listed system of protection against electric shock of personnel. When is a personnel protection system NOT required for EVSE?

A) If the EVSE is permanently wired

B) If the EVSE supplies less than 60 volts dc

C) If the EVSE is located outdoors

D) If the EVSE is located in a secured area

15 / 80

15. What is the maximum length permitted for flexible metal conduit used to connect physically adjustable equipment in ducts specifically fabricated to transport environmental air?

A) 1.2 m (4 ft)

B) 3.0 m (10 ft)

C) 0.9 m (3 ft)

D) 1.8 m (6 ft)

16 / 80

16. Where a feeder supplies guest rooms and guest suites of hotels and motels, what protection device is required to be installed?

A) Oversized neutral conductor

B) Surge-protective device (SPD)

C) Arc-fault circuit interrupter

D) Ground-fault equipment protection

17 / 80

17. Where permitted, Type 1 SPDs may be connected to the supply side of the service disconnect as permitted in which section?

A) 242.14

B) 242.54

C) 230.70(A)

D) 230.82(4)

18 / 80

18. Which type of luminaire, when supplied by a circuit exceeding 120 volts but not exceeding 277 volts to ground, must have its medium-base or smaller screw shell lampholders supplied at 120 volts or less from an integral stepdown power supply?

A) Luminaires equipped with mogul-base screw shell lampholders

B) Luminaires without lampholders

C) Electric-discharge luminaires with integral ballasts

D) Incandescent or LED luminaires

19 / 80

19. Is RTRC permitted for the support of luminaires?

A) Only if the conduit is Schedule 80

B) Yes, always

C) No, for the support of luminaires or other equipment not described in 355.10(H)

D) Yes, only if the luminaire weighs less than 7 kg (15 lb)

20 / 80

20. If the ESS disconnecting means has line and load terminals that could be energized in the open position, what warning must the device be marked with?

A) DANGER: HIGH SHORT CIRCUIT CURRENT

B) WARNING: DO NOT DISCONNECT UNDER LOAD

C) WARNING ELECTRIC SHOCK HAZARD TERMINALS ON THE LINE AND LOAD SIDES MAY BE ENERGIZED IN THE OPEN POSITION

D) CAUTION: MULTIPLE SOURCES OF POWER

21 / 80

21. Plug fuses of 15-ampere and lower rating must be identified by what specific configuration?

A) White color coding

B) Nonrenewable design

C) Metallic screw shell

D) Hexagonal configuration of the window, cap, or other prominent part

22 / 80

22. Routinely operated control and instrument transfer switch handles or push buttons shall be in a readily accessible location at an elevation of not over what maximum height?

A) 6 ft.

B) 1.7 (m) / 66 (in)

C) 6ft 7in

D) 8ft 2in

23 / 80

23. Which grounding electrodes, if present at each building or structure served, must be bonded together to form the grounding electrode system?

A) Only the nearest metal underground structure

B) Only plate and rod electrodes

C) All grounding electrodes described in 250.52(A)(1) through (A)(7)

D) Only metal structural frame and water pipe

24 / 80

24. What type of plate must be installed at each end of the flexible bus system?

A) A fire-rated plate

B) A caution plate

C) A system nameplate

D) A serial number plate

25 / 80

25. A single installation of surge arresters is permitted to protect a number of interconnected circuits if no circuit is exposed to surges while disconnected from what device?

A) The surge arresters

B) The service disconnect

C) The transformer

D) The grounding electrode

26 / 80

26. What is the maximum size required for a copper bonding conductor connecting exposed structural metal?

A) 500 kcmil copper

B) 4/0 AWG copper

C) 3/0 AWG copper

D) 2/0 AWG copper

27 / 80

27. Secondary conductors operating over 1000 volts shall be separated from each other and from all objects other than insulators or neon tubing by a spacing of not less than what distance?

A) 30 mm (1 1/4 in.)

B) 25 mm (1 in.)

C) 50 mm (2 in.)

D) 38 mm (1 1/2 in.)

28 / 80

28. The EVSE load shall be calculated at the nameplate rating of the equipment or what minimum wattage (volt-amperes), whichever is larger?

A) 7200 watts

B) 5000 watts

C) 6000 watts

D) 6500 watts

29 / 80

29. When using fixed electrostatic equipment, goods being coated shall be supported on conveyors or hangers arranged to ensure that the parts are electrically connected to ground with a resistance of what maximum value?

A) 10(kilohms) or less

B) 1 (megohm) or less

C) 500(kilohms) or less

D) 100(kilohms) or less

30 / 80

30. What are the permitted flat copper conductor sizes (equivalent AWG) used in concealable nonmetallic extensions?

A) 16 AWG or 14 AWG

B) 10 AWG or 8 AWG

C) 6 AWG or 4 AWG

D) 14 AWG or 12 AWG

31 / 80

31. Type RFHH-3 heat-resistant fixture wire requires a nominal insulation thickness in mils of:

A) 15 (mils)

B) 30 (mils)

C) 45 (mils)

D) 8.4 (mils)

32 / 80

32. Unused current transformers associated with potentially energized circuits shall be:

A) Labeled as disconnected

B) Short-circuited

C) Removed from the circuit

D) Protected by a supplemental fuse

33 / 80

33. What demand factor percentage applies to the portion of health care receptacle load from 5001 VA to 10,000 VA using Table 220.110(1)?

A) 60 percent

B) 35 percent

C) 75 percent

D) 50 percent

34 / 80

34. Which enclosure type is suitable for outdoor use and provides a degree of protection against incidental contact, rain, snow, and sleet, but NOT windblown dust?

A) Type 4

B) Type 3R

C) Type 3

D) Type 3X

35 / 80

35. When PVC, RTRC, or HDPE conduit is used underground below classified locations, RMC or IMC conduit must be used for the last 2 ft. of the run to emergence, and what must also be included?

A) An equipment grounding conductor

B) A lightning arrester

C) A conduit seal

D) A bonding jumper

36 / 80

36. An SPD shall not be installed on ungrounded systems unless listed specifically for use on which systems?

A) Any system with a single point ground

B) Any system over 480 volts

C) Only solidly grounded wye systems

D) Ungrounded systems, impedance grounded systems, or corner grounded delta systems

37 / 80

37. No overcurrent device shall be connected in series with any conductor that is intentionally grounded, unless the overcurrent device meets one of two conditions. What is one of the permitted conditions?

A) The overcurrent device opens all conductors of the circuit, including the grounded conductor, and is designed so that no pole can operate independently

B) It is rated for supplementary protection

C) It is a circuit breaker designed for motor circuits only

D) It is a fuse rated 150 volts or less to ground

38 / 80

38. What must be provided for galvanized steel, stainless steel, and red brass RMC installed in concrete, direct contact with the earth, or direct burial applications?

A) Only stainless steel fittings

B) A continuous PVC coating

C) Corrosion protection approved for the condition

D) A layer of noncinder concrete not less than 50 mm (2 in.) thick

39 / 80

39. What must be coordinated to prevent damaging or dangerous temperatures in conductors or conductor insulation under short-circuit conditions?

A) Phase rotation, system voltage, and conductor material

B) The operating time of the protective device, the available short-circuit current, and the conductor used

C) Grounding method, bonding requirements, and equipment listing

D) Cable length, ambient temperature, and load

40 / 80

40. For a wye-start, delta-run connected motor, what is the minimum required ampacity percentage for the conductors between the controller and the motor?

A) 72 percent of the motor full-load current rating

B) 58 percent of the motor full-load current rating

C) 125 percent of the motor full-load current rating

D) 80 percent of the motor full-load current rating

41 / 80

41. For horizontal runs of RTRC supported by openings through framing members, they must be securely fastened within what maximum distance of termination points?

A) 1.2 m (4 ft)

B) 1.8 m (6 ft)

C) 1.5 m (5 ft)

D) 900 mm (3 ft)

42 / 80

42. What is the required calculated load for each 2-wire small-appliance branch circuit in a dwelling unit?

A) 1000 volt-amperes

B) 1800 volt-amperes

C) 1200 volt-amperes

D) 1500 volt-amperes

43 / 80

43. A system or circuit conductor that is intentionally grounded is defined as the:

A) Equipment Grounding Conductor

B) Grounded Conductor

C) Bonding Jumper

D) Supply-Side Bonding Jumper

44 / 80

44. In no case shall the distance between supports for nonmetallic wireways exceed what maximum distance?

A) 0.9 m (3 ft)

B) 3 m (10 ft)

C) 2.5 m (8 ft)

D) 1.5 m (5 ft)

45 / 80

45. A listed Class A GFCI device providing personnel protection must be installed in which type of location?

A) Concealed location

B) Readily accessible location

C) Accessible location

D) Any location per manufacturer instructions

46 / 80

46. Which of the following listed cords is NOT permitted for use in show windows and showcases?

A) Type ST

B) Type SEO

C) Type HPD

D) Type SJOOW

47 / 80

47. In dry locations, conductors in open wiring on insulators enclosed in flexible nonmetallic tubing must be in continuous lengths not exceeding what distance?

A) 4.5 m (15 ft)

B) 6.0 m (20 ft)

C) 3.7 m (12 ft)

D) 3.0 m (10 ft)

48 / 80

48. For devices mounted within a cabinet where the nominal voltage is 251 to 1000, what is the minimum required airspace between the walls, back, or door and the nearest exposed current-carrying part?

A) 12.7 mm (0.500 in.)

B) 19 mm (3/4 in.)

C) 22.2 mm (7/8 in.)

D) 25.4 mm (1.00 in.)

49 / 80

49. For an outside tap of unlimited length, where must the disconnecting means for the tap conductors be installed?

A) At a readily accessible location complying with 240.21(B)(5)(4)

B) Inside the feeder panel

C) At a readily accessible location outside the building or structure

D) Remote from the tap connection

50 / 80

50. In areas subject to vehicular traffic (Column 6), what is the minimum cover required for direct-buried cables (Column 1), regardless of voltage level?

A) 550 mm (22 in.)

B) 600 mm (24 in.)

C) 500 mm (20 in.)

D) 450 mm (18 in.)

51 / 80

51. What is the maximum length permitted for the cord or cable from a busway plug-in device to a suitable tension take-up support device?

A) 1.5 m (5 ft)

B) 0.9 m (3 ft)

C) 1.2 m (4 ft)

D) 1.8 m (6 ft)

52 / 80

52. What identification information is required to be marked on all IBP?

A) The installer's name or trademark

B) The manufacturer’s name, trademark, or other distinctive marking by which the organization responsible for the product can be readily identified

C) The model number only

D) The date of manufacture

53 / 80

53. What item must be permanently identified at the fire alarm control unit location for a Non–Power-Limited Fire Alarm (NPLFA) Circuit?

A) The location of the nearest surge protector

B) The date of the last inspection

C) The location of the branch-circuit overcurrent protective device

D) The rating of the fire alarm control unit

54 / 80

54. In a working space intended for equipment operating over 1000 volts, if equipment is less than 1.8 m (6 ft) wide, what entrance requirement applies?

A) At least one entrance is required, not less than 610 mm (24 in.) wide and 2.0 m (6 1/2 ft) high.

B) An entrance is required at each end.

C) Two entrances are required only if the equipment is rated over 1200 A.

D) Two entrances are required if the depth is over 1.2 m (4 ft).

55 / 80

55. Airfield lighting cable used in series circuits that are powered by regulators and installed in restricted airport lighting vaults are permitted as exposed cable installations. True or False?

A) False

B) True

C) False, they must be contained in raceways

D) True, only if rated less than 5kV

56 / 80

56. What information must each section of a flexible bus system be marked with?

A) The minimum rated voltage, size, and weight

B) The installation method, phase rotation, and ambient temperature rating

C) The date of manufacture, material type, and maximum ambient temperature

D) The manufacturer's name or trade designation, voltage rating, and current rating

57 / 80

57. What is the minimum thickness required for sheet steel boxes over 1650 cm³ (100 in.³) in size, uncoated?

A) 1.35 mm (0.053 in.)

B) 2.38 mm (3/32 in.)

C) 1.59 mm (0.0625 in.)

D) 3.17 mm (1/8 in.)

58 / 80

58. If a machine has a total connected resistance heating load of 50 A, a highest rated motor of 30 A, and other connected motors/apparatus totaling 40 A, what is the minimum required ampacity of the supply conductor if all loads may operate simultaneously?

A) 125.0 A

B) 105.0 A

C) 117.5 A

D) 110.0 A

59 / 80

59. Load terminals for ungrounded conductors must be located so that it is not necessary to reach across what specific component to make connections?

A) The enclosure frame

B) Energized uninsulated bus

C) The instrument transformer

D) The grounded conductor terminals

60 / 80

60. Which fixture wire type is explicitly limited to 300 Volts service?

A) Type ZF

B) Type FFH-2

C) Type KF-1

D) Type HF

61 / 80

61. For portable utilization equipment used within a hangar, the flexible cord must be approved for what specific usage?

A) Extra-hard usage

B) Intermittent usage

C) Standard usage

D) Hard usage

62 / 80

62. Areas adjacent to classified locations (such as stock rooms or switchboard rooms) shall be unclassified where mechanically ventilated at a rate of four or more air changes per hour, designed with positive air pressure, or what else?

A) Separated by an unpierced wall, roof, or other solid partition

B) Protected by explosionproof equipment

C) Protected by an automatic fire suppression system

D) Provided with dedicated GFCI protection

63 / 80

63. For an installation consisting of not more than two 2-wire branch circuits, what is the minimum required rating of the feeder or branch-circuit disconnecting means?

A) 30 amperes

B) 15 amperes

C) 20 amperes

D) 60 amperes

64 / 80

64. The interrupting rating of power fuses shall not be less than what value?

A) 10 MVA

B) The available fault current the fuse is required to interrupt

C) 125 percent of the continuous current rating

D) The transformer short-circuit rating

65 / 80

65. What is the ampacity for 4/0 AWG bare copper conductors in free air, based on 80°C total conductor temperature and 40°C ambient temperature?

A) 444 amperes

B) 382 amperes

C) 401 amperes

D) 466 amperes

66 / 80

66. What marking is required for receptacles rated 20(amperes) or less that are designed for the direct connection of aluminum conductors?

A) 20A-MAX

B) AL/CU

C) AL-RATED

D) CO/ALR

67 / 80

67. What is the minimum thickness required for metal ventilating pipes used in Class III locations?

A) 0.40 (mm)/ 0.016 (in)

B) 0.25 (mm)/ 0.01 (in)

C) 0.50 (mm)/ 0.020 (in)

D) 0.53 (mm)/ 0.021 (in)

68 / 80

68. If a retrofit kit is installed in a luminaire according to the installation instructions, is the retrofitted luminaire considered reconditioned?

A) Yes, if the luminaire is installed in a damp location

B) No

C) Yes, if the luminaire is more than 8 ft. above the floor

D) Yes, unless the kit is provided by the original manufacturer

69 / 80

69. For power conductors below communications conductors on poles, what is the minimum required horizontal climbing space?

A) 650 mm (26 in.)

B) 600 mm (24 in.)

C) 750 mm (30 in.)

D) 700 mm (28 in.)

70 / 80

70. What is the requirement regarding the interconnection components required for a complete heating equipment installation?

A) They must be separated by a minimum distance of 1.0 m (3 ft).

B) They shall be guarded.

C) They must be installed in flexible conduit.

D) They must be isolated from ground.

71 / 80

71. Which component is permitted to be used in lieu of a box or terminal where the conductors emerge from a raceway and enter or terminate at equipment such as open switchboards?

A) A conduit seal

B) A metal locknut

C) A reducing washer

D) A bushing

72 / 80

72. What is the maximum voltage permitted for a listed Class 4 power transmitter (source) output?

A) 600 volts peak or dc

B) 300 volts peak or dc

C) 150 volts peak or dc

D) 450 volts peak or dc

73 / 80

73. When running conductors in parallel, what must be true about the insulation type of all paralleled conductors that comprise each ungrounded conductor, grounded conductor, neutral conductor, equipment grounding conductor, equipment bonding jumper, or supply-side bonding jumper?

A) Must be rated for 90°C

B) Must be shielded

C) Must be the same insulation type

D) Must be suitable for wet locations

74 / 80

74. What is the minimum required ampacity for feeder conductors supplying a combination of continuous and noncontinuous loads, if the overcurrent protective device assembly is NOT listed for 100 percent operation?

A) 125 percent of the total load

B) The noncontinuous load plus 125 percent of the continuous load

C) 100 percent of the total load

D) 100 percent of the noncontinuous load plus 100 percent of the continuous load

75 / 80

75. Field-wired conductors between a resistance-type boiler heater and the supplementary overcurrent protective devices must be sized at not less than what percentage of the load served?

A) 125%

B) 115%

C) 100%

D) 120%

76 / 80

76. Luminaires installed between 1.5 m (5 ft) and 3.0 m (10 ft) horizontally from the inside walls of a swimming pool must have GFCI protection unless what exception applies regarding mounting height?

A) They are low-voltage luminaires.

B) They are cord-and-plug connected.

C) Installed not less than 1.5 m (5 ft) above the maximum water level and rigidly attached to the structure.

D) They are totally enclosed and mounted 3.0 m (10 ft) high.

77 / 80

77. Resistance-type immersion electric heating elements are permitted to be subdivided into circuits not exceeding 120(amperes) and protected at not more than 150(amperes) where they are contained in ASME-rated and stamped vessels, included in listed instantaneous water heaters, or installed where?

A) In low-pressure water heater tanks or open-outlet water heater vessels

B) In dwelling unit basements

C) Only in commercial applications

D) In service equipment panels

78 / 80

78. Which characteristic is required to be marked on a Surge-Protective Device (SPD)?

A) Maximum continuous operating voltage

B) Duty cycle rating

C) Short-circuit current rating

D) Nominal discharge current rating

79 / 80

79. In general, the ampacity of branch-circuit conductors shall not be less than what percentage of the designed potential load of utilization equipment that will be operated simultaneously?

A) 100 percent

B) 80 percent

C) 125 percent

D) 115 percent

80 / 80

80. A conductor having no covering or electrical insulation whatsoever is defined as a/an:

A) Bare Conductor

B) Messenger Wire

C) Covered Conductor

D) Insulated Conductor

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2023 Commercial Electrical Inspector – Practice Quiz (Untimed)

“This untimed practice quiz simulates the ICC exam format, giving you full exposure to real-style questions while allowing unlimited time to navigate, learn, and build confidence without time pressure.”