Journeyman Electrician Practice Test 5

Question 1: A 480Y/277-volt, 3-phase service supplies only 3-phase motor loads (no line-to-neutral loads). What does the NEC require for the grounded conductor?

• It may be omitted at the service because no line-to-neutral loads exist
• It must always be the same size as the largest ungrounded service conductor
• It is required only at the utility transformer and may end at the meter
• It must be run to each service disconnect and sized from Table 250.102(C)(1)

NEC Reference: NEC 250.24(C)

Question 2: Which method is NOT acceptable for bonding a service raceway to the service enclosure where a concentric knockout ring remains?

• Standard locknuts on the inside and outside of the enclosure wall
• A grounding bushing with a bonding jumper to the enclosure bus
• A bonding-type locknut listed for the purpose
• A threaded hub made up wrenchtight

NEC Reference: NEC 250.92(B)

Question 3: A 480Y/277-volt feeder in EMT enters a box through a punched concentric knockout (rings left in place). The circuit is more than 250 V to ground. What is required?

• A separate grounding electrode at the box
• An insulated bushing only
• Nothing extra; standard locknuts are enough for feeders
• A bonding jumper or bonding-type fitting, as for services, to ensure continuity

NEC Reference: NEC 250.97

Question 4: Where must the system bonding jumper for a separately derived system (such as a transformer secondary) be installed?

• At a single point, from the source to the first disconnecting means or overcurrent device
• At both the transformer and the first panelboard
• At the building service equipment
• At every panelboard supplied by the transformer

NEC Reference: NEC 250.30(A)(1)

Question 5: An insulated equipment grounding conductor larger than 6 AWG has black insulation. How may it be identified as an EGC?

• By stripping it, coloring it green, or green tape or labels at each end and accessible point
• It cannot be re-identified; a green insulated conductor must be installed instead
• By wrapping white tape around the insulation at each end of the conductor
• By attaching a tag stating "ground" at the panelboard end of the conductor only

NEC Reference: NEC 250.119(A)

Question 6: What is the full-load secondary current of a 25 kVA, single-phase transformer with a 240-volt secondary?

• 60.1 A
• 104.2 A
• 120.3 A
• 208.3 A

Question 7: Using the optional method for a dwelling unit, the general loads (lighting, small-appliance, laundry, appliances, dryer and range) total 30,000 VA. What is the demand for these general loads, before heating or air-conditioning is added?

• 12,000 VA
• 16,000 VA
• 18,000 VA
• 30,000 VA

NEC Reference: NEC 220.82(B)

Question 8: A motor delivers 10 hp of mechanical output at 88% efficiency. What is its electrical input power?

• 9.33 kW
• 8.48 kW
• 7.46 kW
• 6.56 kW

Question 9: In a dwelling bathroom, at least one receptacle outlet must be installed within what distance of the outside edge of each basin?

• 18 in.
• 24 in.
• 3 ft
• 6 ft

NEC Reference: NEC 210.52(D)

Question 10: For a one-family dwelling, the 2023 NEC requires an emergency disconnecting means for the service. Where must it be installed?

• At the utility pole
• In the basement next to the panelboard
• Inside the garage within 10 ft of the door
• At a readily accessible outdoor location

NEC Reference: NEC 230.85

Question 11: All services supplying dwelling units must be provided with which device?

• An arc energy reduction switch
• A whole-house AFCI main breaker
• A ground-fault protection of equipment (GFPE) relay
• A Type 1 or Type 2 surge-protective device (SPD)

NEC Reference: NEC 230.67

Question 12: Listed or labeled equipment must be installed and used:

• In accordance with any instructions included in the listing or labeling
• Only in commercial buildings
• However the installer judges to be safe
• Only after approval by the manufacturer's representative

NEC Reference: NEC 110.3(B)

Question 13: A field-applied danger, warning or caution label required by the NEC must:

• Be placed only on the inside of the equipment door where it is protected
• Use red lettering, but it may be on any background color the installer chooses
• Be handwritten in permanent marker so that it can be updated easily on site
• Be permanently affixed, not handwritten (except variable data), and durable

NEC Reference: NEC 110.21(B)

Question 14: On a 120/240-volt, 3-phase, 4-wire delta system, what is the approximate voltage from the high leg to the neutral, and how must that conductor be identified?

• 120 V; marked white
• 208 V; marked orange
• 240 V; marked red
• 277 V; marked brown

NEC Reference: NEC 110.15

Question 15: A conduit is installed on a rooftop exposed to direct sunlight, with the bottom of the raceway less than 7/8 in. above the roof. The outdoor design temperature is 40 °C. What ambient temperature must be used for the ampacity correction?

• 40 °C
• 57 °C
• 73 °C
• 80 °C

NEC Reference: NEC 310.15(B)(2)

Question 16: Type UF cable is NOT permitted to be used:

• As service-entrance cable
• In wet locations
• For direct burial
• As a branch circuit in a dwelling

NEC Reference: NEC 340.12

Question 17: For general wiring at 0–2,000 volts, what is the smallest aluminum or copper-clad aluminum conductor permitted?

• 14 AWG
• 12 AWG
• 10 AWG
• 8 AWG

NEC Reference: NEC 310.3(A)

Question 18: A circuit breaker can be adjusted to a continuous current trip setting of 1,200 A or higher. What does 240.87 require?

• A ground-fault relay on the breaker that is set to trip at not more than 30 mA
• A second, smaller circuit breaker installed in series on the line side of the breaker
• Only a field label showing the breaker manufacturer and the date of installation
• Documentation and an arc energy reduction method, such as zone-selective interlocking

NEC Reference: NEC 240.87

Question 19: An overcurrent device may be connected in series with an intentionally grounded conductor only where:

• The device opens all conductors of the circuit simultaneously, including the grounded conductor
• The device is a fuse
• The grounded conductor is larger than 6 AWG
• The circuit is rated 15 A or less

NEC Reference: NEC 240.22

Question 20: Which current value is used to size separate motor overload protection?

• The full-load current from Table 430.250
• The branch-circuit breaker rating
• The locked-rotor current
• The motor nameplate full-load current

NEC Reference: NEC 430.6(A)(2)

Question 21: A continuous-duty motor has no service factor or temperature rise marking. Its nameplate full-load current is 18 A. What is the maximum rating of a separate overload device?

• 18 A
• 20.7 A
• 22.5 A
• 25.2 A

NEC Reference: NEC 430.32(A)(1)

Question 22: For a new outdoor swimming pool installation, luminaires located within 5 ft horizontally of the inside walls of the pool must be at least how high above the maximum water level?

• 5 ft
• 7½ ft
• 10 ft
• 12 ft

NEC Reference: NEC 680.22(B)(1)

Question 23: A legally required standby system must have power available within how many seconds of failure of the normal supply?

• 10 seconds
• 30 seconds
• 60 seconds
• 120 seconds

NEC Reference: NEC 701.12

Question 24: A Class II location is hazardous because of the presence of:

• Corrosive liquids
• Flammable gases or vapors
• Combustible dust
• Ignitible fibers or flyings

NEC Reference: NEC 500.5(C) and 500.6(B)

Question 25: In a hospital, each general care patient bed location must be provided with at least how many receptacles?

• 4
• 6
• 8
• 14

NEC Reference: NEC 517.18(B)

Question 26: In a dwelling unit, which 125-volt, 15-ampere receptacle is NOT required to be tamper-resistant?

• A receptacle located more than 5½ ft above the floor
• A kitchen countertop receptacle
• An outdoor receptacle at a deck
• A garage receptacle 18 in. above the floor

NEC Reference: NEC 406.12

Question 27: A listed household range hood is cord-and-plug connected. What cord length is permitted?

• 6 in. to 18 in.
• 18 in. to 36 in.
• 3 ft to 4 ft
• 4 ft to 6½ ft

NEC Reference: NEC 422.16(B)(4)

Question 28: Expansion fittings must be provided in a run of rigid PVC conduit when the expected change in length due to thermal expansion and contraction is at least:

• 1/8 in.
• 1/4 in.
• 1/2 in.
• 1 in.

NEC Reference: NEC 352.44

Question 29: A metal wireway holds 24 current-carrying conductors and is filled to 18% of its cross-sectional area. Which statement is correct?

• The 20% fill limit is exceeded
• No ampacity adjustment is required, and the fill is within the 20% limit
• Ampacity adjustment factors must be applied because there are more than 3 conductors
• Wireways may not contain more than 9 current-carrying conductors

NEC Reference: NEC 376.22

Question 30: A 3 kVA, single-phase transformer has a 480-volt primary and primary-only protection. What is the maximum primary fuse rating?

• 20 A
• 15 A
• 10 A
• 6 A

NEC Reference: NEC Table 450.3(B)