2023 Commercial Electrical Inspector – Practice Quiz (Untimed)

2023 Commercial Electrical Inspector (Untimed)

80 Questions

3.5 Hours

1 / 80

1. Surge arresters shall be made inaccessible to unqualified persons unless they are what?

A) Installed at a height greater than 3.0 m (10 ft)

B) Listed for installation in accessible locations

C) Protected by a fence

D) Mounted on the exterior of the building

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2. If multiple switches are permitted as the disconnecting means for one set of fuses, how must they be interlocked?

A) They must not be interlocked

B) Electrically interlocked to permit access to the fuses only when one switch is open

C) Mechanically or electrically interlocked to permit access to the fuses only when all switches are open

D) With a key interlock requiring a qualified person to hold the key

3 / 80

3. Adjustment factors shall not apply to conductors installed in raceways having a length not exceeding what maximum distance?

A) 1.8 m (6 ft)

B) 600 mm (24 in.)

C) 1.0 m (40 in.)

D) 300 mm (12 in.)

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4. Ampacities of conductors not shown in the tables but meeting general wiring requirements shall be permitted to be determined by interpolation based on what characteristic?

A) Conductor diameter

B) Conductor’s circular-mil area

C) Conductor weight per foot

D) Conductor length

5 / 80

5. What specific warning wording must be applied adjacent to the back-fed circuit breaker from a Power Source when the 120% busbar rule (705.12(B)(2)) is used?

A) DANGER: TWO SOURCES OF POWER

B) CAUTION: DO NOT OPERATE UNDER LOAD

C) WARNING: HIGH VOLTAGE TERMINALS

D) WARNING: POWER SOURCE OUTPUT DO NOT RELOCATE THIS OVERCURRENT DEVICE.

6 / 80

6. When Power Sources are operating in Island Mode, how must the voltage and frequency be controlled?

A) Must match the utility supply exactly.

B) Must be maintained at 60 Hz and 120/240 V only.

C) Controlled so that voltage and frequency are supplied within limits compatible with the connected loads.

D) Must be continuously monitored by a qualified person.

7 / 80

7. For a circuit operating at 25 kV between phases, what is the minimum required elevation for unguarded live parts above the working space?

A) 2.7 m (9 ft)

B) 3.0 m (10 ft)

C) 2.9 m (9 ft 6 in.)

D) 2.8 m (9 ft 3 in.)

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8. For equipment provided with threaded entries for metric-threaded fittings, how many threads must be fully engaged when metric-threaded fittings are installed?

A) Seven threads

B) Three threads

C) Five threads

D) Ten threads

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9. The surge arrester must be connected to which of the following locations?

A) The supply side of the service disconnect

B) Equipment grounding terminal in the service equipment

C) The grounded service conductor

D) The nearest structural steel

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10. Which of the following is considered an acceptable means for connecting 10 AWG conductors to terminal parts?

A) By solder lugs without mechanical security

B) By pressure connectors only

C) By means of wire-binding screws or studs and nuts that have upturned lugs or the equivalent

D) By wire-binding screws only

11 / 80

11. If a short-circuit and ground-fault protective device is used for both windings of a part-winding motor (Exception), and time-delay (dual-element) fuses are used, what is the maximum permissible rating?

A) 125 percent of the motor full-load current

B) 150 percent of the motor full-load current

C) 200 percent of the motor full-load current

D) 175 percent of the motor full-load current

12 / 80

12. Luminaires permitted in commercial cooking hoods must be constructed so that what materials are excluded from the lamp and wiring compartment?

A) Condensation and moisture

B) Steam and heat

C) Salt and corrosive agents

D) Exhaust vapors, grease, oil, or cooking vapors

13 / 80

13. In industrial establishments, if the cord or cable between the busway plug-in device and the tension take-up support device exceeds 1.8 m (6 ft), what is the maximum support interval required for the cord or cable?

A) 2.5 m (8 ft)

B) 3.0 m (10 ft)

C) 1.8 m (6 ft)

D) 3.7 m (12 ft)

14 / 80

14. When calculating shore power using Table 220.120, if individual kilowatt-hour submeters are installed for each slip, the total demand amperes shall be permitted to be multiplied by what factor to achieve the final demand amperes?

A) 0.9

B) 1.25

C) 0.85

D) 1.1

15 / 80

15. All sections of contact conductors must be mechanically joined to provide which condition?

A) A continuous physical path

B) Overcurrent protection

C) A grounded connection

D) A continuous electrical connection

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16. Which insulated conductor type is explicitly exempted from the rooftop ampacity adjustment (temperature adder)?

A) Type TW insulated conductors

B) Type RHH insulated conductors

C) Type THWN-2 insulated conductors

D) Type XHHW-2 insulated conductors

17 / 80

17. What must be done to all cut ends of HDPE conduit?

A) Sealed with approved compound

B) Painted with corrosion-resistant enamel

C) Trimmed inside and outside to remove rough edges

D) Tapered for a standard fitting

18 / 80

18. What is the maximum length permitted for a flexible cord used as a transition between manufactured wiring system components and utilization equipment not permanently secured?

A) 2.5 m (8 ft)

B) 1.8 m (6 ft)

C) 3.0 m (10 ft)

D) 1.5 m (5 ft)

19 / 80

19. The overall system governing the starting, stopping, direction of motion, acceleration, speed, and retardation of the moving member is defined as the:

A) Control System

B) Controller

C) Utilization Equipment

D) Control Circuit

20 / 80

20. How is the maximum current for a Solar PV source circuit calculated if using the standard method (not the industry standard design method)?

A) The sum of the short-circuit current ratings of the PV modules connected in parallel multiplied by 125 percent.

B) The rated short-circuit current of the largest PV module multiplied by 125 percent.

C) The sum of the PV module short-circuit current ratings multiplied by 100 percent.

D) The sum of the PV module rated current multiplied by 125 percent.

21 / 80

21. Where used at a point on a circuit, to which conductors must a surge arrester be connected?

A) All conductors, including the static wire

B) Only the phase conductors

C) Only the grounded conductor

D) Each ungrounded conductor

22 / 80

22. When operating portable and vehicle-mounted generators, exhaust must be vented away from structures and other areas where what might occur?

A) People might congregate

B) High winds might occur

C) Animals might be present

D) Flammable vapors might accumulate

23 / 80

23. A multiwire branch circuit is permitted to supply line-to-line loads if the circuit supplies only one piece of utilization equipment. True or False?

A) False, only line-to-neutral loads are permitted

B) True

C) False, unless the equipment is rated less than 1/4 hp

D) True, provided the load is noncontinuous

24 / 80

24. When calculating the floor area for a dwelling unit, which area must NOT be included?

A) Unfinished areas not adaptable for future use as a habitable room

B) Open-sided carports

C) Garages with finished ceilings

D) Storage rooms connected by interior access

25 / 80

25. If required by the AHJ, a diagram showing feeder details must be provided prior to installation. Which detail is NOT required to be shown on this diagram?

A) The size and type of conductors to be used

B) The total calculated load before applying demand factors

C) The demand factors used

D) The resistance value of the equipment grounding conductor

26 / 80

26. Flexible cord used for connecting showcases must be of the hard-service type, have conductors not smaller than the branch-circuit conductors, and include what third component?

A) A 90 (C) temperature rating

B) An equipment grounding conductor

C) A metallic outer sheath

D) A strain relief device

27 / 80

27. In addition to its control thermostat, all storage or instantaneous-type water heaters must be equipped with what to disconnect all ungrounded conductors?

A) An internal fuse

B) A temperature-limiting means

C) A pressure relief valve

D) An auxiliary disconnect

28 / 80

28. When the depth of the working space is doubled (twice that required by 110.26(A)(1)), what is permitted regarding the entrance to and egress from the working space?

A) Two entrances are still required

B) The width of the entrance can be reduced

C) No entrance is required if serviced remotely

D) A single entrance shall be permitted

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29. Which types of RMC are permitted under all atmospheric conditions and occupancies?

A) All listed types of RMC

B) Only galvanized steel RMC

C) Galvanized steel, stainless steel, and red brass RMC

D) Aluminum and galvanized steel RMC

30 / 80

30. According to Table 722.135(B), are General-Purpose cables (non-plenum rated) permitted to be installed in other spaces used for environmental air (plenums)?

A) No (N)

B) Yes, if installed in metal raceway

C) Yes, only if smaller than 6.35 mm (0.25 in.) in diameter

D) Yes, if less than 3.05 m (10 ft) in exposed length

31 / 80

31. Reconditioned motors identified for use in hazardous (classified) locations must be listed as reconditioned if installed in what type of location?

A) Hazardous (classified) locations

B) Dry locations

C) Wet locations

D) Indoor industrial locations

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32. Where grounded conductors of different nominal voltage systems originate, the means of identification used must be documented in a manner that is readily available or must be permanently what?

A) Submitted to the AHJ

B) Kept on file at the main office

C) Embossed on the equipment panel

D) Posted

33 / 80

33. For which size conductors is protection against abrasion referenced in an informational note regarding EMT entry into an enclosure?

A) Size 6 AWG or larger

B) All conductors regardless of size

C) Size 1/0 AWG or larger

D) Size 4 AWG or larger

34 / 80

34. In commercial garages, how are precast cellular concrete floor raceways permitted to be used?

A) Only for supplying wall outlets

B) Not permitted at all

C) Only for supplying ceiling outlets or extensions to the area below the floor but not above

D) Only for lighting circuits

35 / 80

35. Fuseholders of the Edison-base type shall only be installed where they are made to accept what type of fuses by the use of adapters?

A) Nonrenewable fuses

B) Renewable fuses

C) Class CC fuses

D) Type S fuses

36 / 80

36. Which requirement must be met by all conductors and equipment used on circuits over 1000 volts, nominal?

A) They must be Type MV cable.

B) They must be permanently enclosed in metal raceway.

C) They shall comply with Part I of this article.

D) They must comply with Part V only.

37 / 80

37. In a completed installation, when must an outlet box containing a ceiling-suspended (paddle) fan be provided with a cover?

A) Always, regardless of canopy installation

B) Unless covered by means of a ceiling-suspended (paddle) fan canopy

C) Only when located in a wet location

D) When the conductors are larger than 12 AWG

38 / 80

38. How must a dimmer or relay system used as a control device for energizing Emergency Systems lighting circuits be listed?

A) Listed as a surge suppression device

B) Listed for use in emergency systems

C) Listed for continuous duty

D) Listed for 100% selective coordination

39 / 80

39. Besides limited smoke, what is another special characteristic that fixture wires listed in Table 402.3 are permitted to be surface marked to indicate?

A) Sunlight resistance

B) Abrasion resistance

C) Low temperature flexibility

D) High voltage resistance

40 / 80

40. For bonded portable generators / 15(kW) or smaller), where must GFCI protection be provided?

A) On all 250 volt receptacle outlets

B) Only on 20(ampere) receptacle outlets

C) Only on GFCI listed receptacles

D) On all 125 volt , 15text{-} and 20(ampere) receptacle outlets

41 / 80

41. Each grounded conductor must terminate within the panelboard in what type of terminal?

A) The main neutral terminal

B) An identified busbar

C) A double-lug terminal

D) An individual terminal that is not also used for another conductor

42 / 80

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

A) A lockout/tagout procedure

B) An operating instruction manual

C) A remote operation handle

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

43 / 80

43. Equipment enclosed in a manner that excludes dusts and does not permit arcs, sparks, or heat generated inside the enclosure to ignite exterior accumulations of a specified dust is defined as what?

A) Encapsulation

B) Dusttight

C) Pressurized Enclosure

D) Dust-Ignitionproof

44 / 80

44. If conductors of higher ampacity are used for a branch circuit rated 30 amperes, what determines the circuit rating?

A) The calculated continuous load

B) The maximum permitted ampere rating or setting of the overcurrent device

C) The conductor ampacity rating

D) The conductor insulation temperature rating

45 / 80

45. For the optional dwelling unit calculation, the remainder of the General Loads (after the first 10 kVA) is calculated at what percentage?

A) 25 percent

B) 50 percent

C) 40 percent

D) 65 percent

46 / 80

46. If conductors or cables rated at a temperature higher than the listed temperature rating of HDPE conduit are installed, at what temperature shall they be operated?

A) Not at a temperature higher than the listed temperature rating of the HDPE conduit

B) At 75°C (167°F)

C) At the ambient temperature plus 10°C

D) At the temperature rating of the conductor

47 / 80

47. In a completed installation, when must an outlet box be provided with a cover?

A) When the box volume exceeds 1160(mm) squared

B) Always

C) Unless covered by a luminaire canopy, lampholder, receptacle, or similar device

D) Only in wet or damp locations

48 / 80

48. Which type of equipment shall NOT be reconditioned?

A) Permanently installed utilization equipment

B) Cord-and-plug connected equipment rated 1440 VA or less

C) Motors rated less than 1/4 hp

D) Equipment that provides ground-fault circuit-interrupter protection for personnel

49 / 80

49. Mobile servicing equipment (such as vacuum cleaners or air compressors) that is not suitable for Class I, Division 2 or Zone 2 locations must be designed and mounted such that all fixed wiring and equipment will be at least how high above the floor?

A) 18 in.

B) 3 ft.

C) 2 ft.

D) 12 in.

50 / 80

50. Where are angle connectors prohibited from being used with LFNC?

A) For connections to motors

B) For concealed raceway installations

C) Where subject to physical damage

D) In wet locations

51 / 80

51. For Utility-Controlled Equipment, such as meter socket enclosures, where an electric Power Production Source is connected to a service, what is the connection requirement?

A) Connections must be listed for backfeed.

B) Only connections approved by the electric utility shall be permitted.

C) Connection must comply with 230.33.

D) Connections must be made using listed splices or taps.

52 / 80

52. The short-circuit current rating requirement for SPDs does NOT apply to which specific devices?

A) Type 2 SPDs

B) SPD components

C) Type 1 SPDs

D) Receptacles

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

A) 230.82(4)

B) 230.70(A)

C) 242.54

D) 242.14

54 / 80

54. For surface marking, information other than the AWG size or circular mil area shall be repeated at intervals not exceeding what maximum distance?

A) 300 mm (12 in.)

B) 610 mm (24 in.)

C) 1.5 m (60 in.)

D) 1.0 m (40 in.)

55 / 80

55. If ampacity adjustment factors are waived for surface metal raceways (2500 mm² cross-section minimum and 20% fill maximum), what is the maximum number of current-carrying conductors permitted?

A) 25 in number

B) 30 in number

C) 15 in number

D) 20 in number

56 / 80

56. For elevator use in Class III, Division 1 locations, what cable types are permitted for flexible connections?

A) Type PLTC or Type ITC

B) Type EO, Type ETP, or Type ETT

C) Type MC-HL, Type MI, or Type P

D) Type SJOOW, Type SOOW, or Type W

57 / 80

57. 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) 60 amperes

B) 15 amperes

C) 30 amperes

D) 20 amperes

58 / 80

58. What must be installed with high-voltage circuit conductors in tunnels?

A) Only Type MI cable

B) A surge protective device

C) An auxiliary gutter for drainage

D) An equipment grounding conductor shall be run with the circuit conductors inside the metal raceway or multiconductor cable jacket.

59 / 80

59. The minimum load used for calculating an individual household electric clothes dryer in a dwelling unit shall be the nameplate rating or what minimum wattage, whichever is larger?

A) 3000 watts

B) 5000 watts (volt-amperes)

C) 4800 watts

D) 4500 watts

60 / 80

60. No overcurrent device shall be inserted in a grounded service conductor except for which device?

A) A current limiter

B) A current transformer

C) A fuse link

D) A circuit breaker that simultaneously opens all conductors of the circuit

61 / 80

61. Where CNG or LNG dispensers are installed beneath a canopy or enclosure, what must the canopy or enclosure be designed to prevent, unless all electrical equipment installed beneath it is suitable for Class I, Division 2 locations?

A) Accumulation or entrapment of ignitible vapors

B) Static electricity buildup

C) Water ingress

D) Physical damage to the dispensers

62 / 80

62. Which type of SPD component assemblies shall only be installed by the equipment manufacturer?

A) Type 4 component assemblies and other component type SPDs

B) All SPDs connected to the grounded conductor

C) Type 3 SPDs

D) Type 1 and Type 2 SPDs

63 / 80

63. For RTRC intended for use aboveground, what characteristic is required regarding heat?

A) It must be able to withstand 90°C ambient temperature

B) It must be resistant to distortion from heat under conditions likely to be encountered in service

C) It must be resistant to sunlight effects

D) It must be UV resistant

64 / 80

64. Suitable covers shall be installed on all boxes, fittings, and similar enclosures to prevent accidental contact with energized parts or what other type of damage?

A) Exposure to sunlight

B) Contaminant accumulation

C) Physical damage to parts or insulation

D) Vibration

65 / 80

65. In industrial establishments, the isolation transformer output voltage is permitted to be up to 132 Volts ac to ground, provided the pipeline or vessel being heated is completely enclosed in what?

A) A grounded metal enclosure

B) Thermal insulation

C) An accessible control cabinet

D) Rigid nonmetallic conduit

66 / 80

66. Battery and other low-voltage circuits in a park trailer must be physically separated from circuits of a different power source by at least what minimum gap?

A) 10 mm (3/8 in.)

B) 13 mm (1/2 in.)

C) 20 mm (3/4 in.)

D) 6 mm (1/4 in.)

67 / 80

67. The 38 mm (1 1/2 in.) spacing requirement under metal-corrugated sheet roof decking is NOT required if the roof decking is covered with a minimum thickness of what material?

A) 32 mm (1 1/4 in.) gravel

B) 50 mm (2 in.) concrete slab

C) 45 mm (1 3/4 in.) wood decking

D) 25 mm (1 in.) rigid insulation

68 / 80

68. What additional marking is required on LFMC, besides being marked according to 110.21?

A) The ampacity rating

B) The maximum conductor size

C) The maximum voltage rating

D) The trade size and other information required by the listing

69 / 80

69. When PVC or RTRC conduit is used underground in Zone 1 locations, how far must RMC or IMC conduit extend for the last portion of the underground run to emergence?

A) 12 in.

B) 24 in.

C) 18 in.

D) 36 in.

70 / 80

70. What is the maximum voltage permitted between conductors for supply circuits operating swimming pool underwater luminaires?

A) 250 volts

B) 120 volts

C) 300 volts

D) 150 volts

71 / 80

71. The rating of the service disconnect for GFPE consideration is considered to be the rating of the largest fuse that can be installed or what setting for a circuit breaker?

A) 125 percent of the continuous load trip setting

B) The highest continuous current trip setting

C) The short-time current rating

D) The lowest instantaneous trip setting

72 / 80

72. When using actual maximum demand data for existing installations, the maximum demand at 125 percent plus the new load shall not exceed what requirement?

A) 80 percent of the conductor ampacity

B) The overcurrent protection device rating

C) The ampacity of the feeder or rating of the service

D) 150 percent of the existing maximum demand

73 / 80

73. Retrofit trip units must be listed for use with what specific component?

A) The panelboard manufacturer

B) The specific circuit breaker with which it is installed

C) The supply voltage

D) The feeder conductor size

74 / 80

74. Power distribution blocks installed on service conductors must be marked with what specific equivalent wording?

A) "Listed for 100% duty"

B) "Suitable for use as service equipment"

C) "Max 600 Volts"

D) "Suitable for use on the line side of the service equipment"

75 / 80

75. A demand factor of 75 percent is permitted for what minimum number of fixed appliances (1/4 hp or greater, or 500 watts or greater) served by the same feeder or service in a dwelling unit?

A) Two or more

B) Three or more, if over 1 kW

C) Three or more

D) Four or more

76 / 80

76. ENT is prohibited where subject to ambient temperatures in excess of what value, unless listed otherwise?

A) 60°C (140°F)

B) 50°C (122°F)

C) 75°C (167°F)

D) 90°C (194°F)

77 / 80

77. For ungrounded or unigrounded primary systems, a spark gap or listed device used for interconnection must have a 60-Hz breakdown voltage of at least twice the primary circuit voltage but not necessarily more than what maximum voltage?

A) 8 kV

B) 5 kV

C) 10 kV

D) 15 kV

78 / 80

78. Busways shall be marked in such a manner that the required information is visible at what time?

A) Only before installation

B) Only during maintenance

C) Only on the end caps

D) After installation

79 / 80

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

A) 125%

B) 115%

C) 100%

D) 150%

80 / 80

80. Which of the following wiring methods is limited to a maximum length of 1.8 m (6 ft) when used for service-entrance conductors?

A) Flexible metal conduit (FMC)

B) Type MI cable

C) Rigid polyvinyl chloride conduit (PVC)

D) Electrical metallic tubing (EMT)

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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.”