2023 Commercial Electrical Inspector – Practice Exam

1. For a circuit operating at a nominal voltage of 480Y/277 volts, what is the minimum required depth of working space in front of exposed live parts, where there are grounded parts on the opposite side (Condition 2)?

2. When making manual bends in ENT, the radius of the curve to the centerline shall not be less than shown in Table 2, Chapter 9, using which column?

3. Which two types of threaded conduit are permitted as wiring methods in Class I, Division 1 locations?

4. For capacitors over 1000 Volts, what is the maximum time permitted for the residual voltage to be reduced to 50 Volts or less after disconnection from the source of supply?

5. If reconditioned equipment is marked with the term “reconditioned” or equivalent, what must be done with the original listing mark?

6. When equipment rated 800 amperes or more that contains overcurrent devices is installed, and a personnel door is located less than 7.6 m (25 ft) from the nearest edge of the working space, how must the door be equipped?

7. What wire fill calculation percentage must be used for strut-type channel raceways with internal joiners?

8. Horticultural lighting equipment shall not be installed as lighting for general illumination unless which condition is met?

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

10. When service-entrance conductors are installed in a cable tray, how must the cable tray be identified?

11. If an ESS employs a diversion charge controller as the sole means of regulating charging, what essential safety feature must the system be equipped with?

12. Where the throw of a double-throw knife switch is vertical, what is required to hold the blades in the open position when set?

13. What is the maximum number of 12 AWG conductors permitted in a standard 100 mm × 54 mm (4 × 2 1/8) round/octagonal box?

14. Receptacles mounted in boxes that are flush with the finished surface or project from it must be installed so the mounting yoke or strap is held rigidly against which component?

15. Electrical equipment installed in agricultural buildings must function at full rating without developing surface temperatures exceeding what?

16. What is the minimum nominal discharge current rating (In) required for a surge-protective device (SPD) installed on a feeder supplying a dwelling unit?

17. Where individual open conductors enter a building, they shall enter through the wall in an upward slant through individual, noncombustible, nonabsorbent insulating tubes, and what must be formed on the conductors before they enter the tubes?

18. For fixed and stationary X-ray equipment, where is the separate control device permitted to be located if not an integral part of the X-ray equipment?

19. For each yoke or strap containing one or more devices or equipment, what volume allowance shall be made based on the largest conductor connected to a device supported by that yoke or strap?

20. Where equipment grounding is required, what must be installed in the LFNC?

21. In a multiple-occupancy building, access to the service disconnecting means supplying more than one occupancy is permitted to be accessible to authorized management personnel only, provided what is maintained?

22. Raceways other than busways or exposed raceways having hinged or removable covers shall be installed complete between outlet, junction, or splicing points prior to what activity?

23. If branch-circuit wiring in a family room (dwelling unit) is extended, AFCI protection shall be provided by any of the approved means described in 210.12(A)(1) through (A)(6), or by installing a listed outlet branch-circuit-type AFCI located where?

24. What is the maximum temperature rating that conductors in outlet boxes supplying luminaires shall be subjected to?

25. What specific requirement applies to pipes or ducts foreign to the electrical installation in the vicinity of high-voltage service equipment or switchgear?

26. Where must electric motor-driven fire pump controllers and power transfer switches be located relative to the motors they control?

27. Interconnection between a surge arrester protecting a transformer and the secondary grounded circuit conductor or grounding electrode conductor requires a metal interconnection if what additional grounding connection exists?

28. If an Emergency System load is supplied by a single feeder, what provision must the system include to facilitate maintenance without jeopardizing continuity of power?

29. Type 3 SPDs are permitted to be installed on the load side of branch-circuit overcurrent protection up to the equipment served. If specified in manufacturer’s instructions, what is the minimum conductor distance required from the service or separately derived system disconnect?

30. What is the minimum required size for overhead service conductors made of aluminum?

31. A box or terminal fitting that has a separately bushed hole for each conductor shall be used wherever a change is made from a raceway or cable to exposed wiring. This fitting is NOT permitted to contain which of the following?

32. Which of the following cable types is permitted as a wiring method in an agricultural building that has a corrosive atmosphere or excessive dust?

33. When grounded neutral conductors of size 2 AWG and 1 AWG are installed in parallel for existing installations, what is required?

34. Which warning signal is not required to be provided (where practicable) for a permanently installed Optional Standby Source?

35. How can the grounded conductor of aerial cable be identified if it does not have a continuous white or gray outer finish?

36. What specific requirement must be met for PVC conduit when used for underground installations?

37. Following a failure of the normal supply, what is the maximum time permitted before an Emergency System must make emergency power and lighting available?

38. What type of material in this Code is included for informational purposes only and is not enforceable as a requirement?

39. Wiring methods permitted in marinas shall be identified for use in wet locations and must contain what type of conductor?

40. If a resistance heating element is not in direct contact with the pipeline or vessel being heated, means must be provided to prevent overtemperature of the heating element unless what design condition applies?

41. What is the minimum vertical clearance required for overhead conductors above the roof surface?

42. Wiring located within the cavity of a non-fire-rated floor–ceiling or roof–ceiling assembly shall NOT be secured to or supported by the ceiling assembly, including the ceiling support wires, unless what condition applies?

43. How many 120-volt, 20-ampere branch circuits must be provided to supply the required bathroom receptacle outlet(s) and any countertop and similar work surface receptacle outlets in a dwelling unit?

44. What type of raceway must also be sealed where a raceway enters a building or structure from outside?

45. If a multifamily dwelling has 15 clothes dryers, what demand factor percentage applies to the total connected dryer load?

46. What general form is NUCC provided in?

47. Which condition permits individual conductors to be installed separately overhead?

48. What conditions must be met for the frame of a portable generator NOT to require a connection to a grounding electrode?

49. Based solely on the AWG or kcmil size range listed in Table 400.4, which cable type accommodates conductors up to 500 kcmil?

50. Electrical connections to the battery, and the cable(s) between cells on separate levels or racks, shall not put what on the battery terminals?

51. Concealable nonmetallic extensions, when identified for the use, shall be permitted to be concealed with which of the following materials?

52. After installation, receptacle faces must project a minimum of what distance from metal faceplates?

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

54. Conductors installed under not less than 50 mm (2 in.) of concrete beneath a building are considered to be located where?

55. What is the maximum permitted overcurrent protection for 10 AWG copper conductors, after correction factors are applied?

56. For the purpose of this Code, which system of measurement is the preference?

57. What is the maximum duration that temporary feeder conductors used to connect a generator for repair or emergencies are permitted to operate without ground-fault protection of equipment?

58. Where must feeder and branch-circuit conductors have overcurrent protection located?

59. In Zone 20 restricted industrial establishments, which cable type is permitted if it has a continuous corrugated metallic sheath, an overall jacket, and a separate equipment grounding conductor(s) in accordance with 250.122?

60. What material shall junction boxes be made of in cellular concrete floor raceways?

61. If a single-phase, 2-wire ESS output is connected to the grounded/neutral conductor of a 3-wire system, the ampacity of the grounded/neutral conductor shall not be exceeded by the sum of the maximum unbalanced neutral load current plus what other rating?

62. Equipment intended for use in electroplating processes must be identified for what?

63. In industrial occupancies, autotransformers are permitted to supply nominal 600-volt loads from nominal 480-volt systems without a connection to a grounded conductor, provided what condition is met regarding personnel?

64. A maximum of how many cord-connected showcases, other than fixed, are permitted to be coupled together by flexible cord and separable locking-type connectors?

65. Demand factors for household cooking appliance loads may be applied if the individual load is in excess of what rating?

66. What restriction applies to joints in vertical runs of metal wireways between supports?

67. Power-limited control power sources, other than transformers, shall be protected by overcurrent devices rated at not more than what percentage of the volt-ampere rating of the source divided by the rated voltage?

68. For a general lighting load of 15,000 VA in a Warehouse (storage), what is the calculated demand load (VA) using Table 220.45?

69. For portable EVSE, where the personnel protection system interrupting device is within the supply equipment enclosure, what is the maximum length permitted for the power-supply cord?

70. Nonshielded single-conductor cables with insulation types up to 2000 volts listed for direct burial are permitted to be directly buried only in which location type, provided maintenance ensures only qualified persons service the cable?

71. Where leads emerge within a concrete or poured masonry floor slab, what must be used?

72. Interrupter switches must be coordinated electrically with accompanying fuses or circuit breakers so that they will safely withstand the effects of closing, carrying, or interrupting all possible currents up to what maximum rating?

73. What material is expressly prohibited from being considered an effective ground-fault current path?

74. Where a cable or raceway passes through bored holes in wood members, the edge of the hole must be not less than what minimum distance from the edge of the wood member?

75. If a bushing is used where oils, grease, or other contaminants may be present, what requirement applies to the bushing material?

76. Generally, what must be required for all splices in temporary wiring installations?

77. For fixed multioutlet assemblies in commercial occupancies where appliances are unlikely to be used simultaneously, each 1.5 m (5 ft) or fraction thereof shall be considered as one outlet of not less than how many volt-amperes?

78. At all termination points of the AC cable armor, what must be provided to protect wires from abrasion, unless equivalent protection is afforded by the box design?

79. What demand factor percentage applies to the portion of non-dwelling receptacle load remainder over 10 kVA in Table 220.47?

80. For feeder taps over 7.5 m (25 ft) long supplying high bay manufacturing buildings, the tap conductors must be sized at least 6 AWG copper or what minimum size aluminum?