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ICC E3 practice questions

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Question 1Electrical Code and Plan Review Fundamentals

Which publication is the primary model code for electrical installations adopted in most U.S. jurisdictions?

  1. The International Building Code
  2. NFPA 101, the Life Safety Code
  3. NFPA 70E, the Standard for Electrical Safety in the Workplace
  4. NFPA 70, the National Electrical Code Correct answer.

Explanation

NFPA 70, the National Electrical Code, governs the design and installation of electrical systems and is the model most jurisdictions adopt or amend. NFPA 70E addresses workplace electrical safety rather than installation requirements, and the building code covers construction broadly.

Question 2Electrical Code and Plan Review Fundamentals

On a set of construction drawings, the branch-circuit wiring between a panelboard and receptacles is typically shown on which drawing type?

  1. Electrical power plan Correct answer.
  2. Structural framing plan
  3. Mechanical equipment schedule
  4. Architectural floor plan

Explanation

Electrical power plans show panelboards, circuits, devices, and wiring routes. Architectural, structural, and mechanical drawings depict other disciplines and are used only for coordination.

Question 3Electrical Code and Plan Review Fundamentals

A plan reviewer needs the adopted edition of the electrical code plus any local amendments. Where should that information be confirmed?

  1. The electrical contractor's bid documents
  2. The manufacturer's installation instructions
  3. The engineer's seal on the drawings
  4. The authority having jurisdiction Correct answer.

Explanation

The authority having jurisdiction adopts and enforces the code edition and any local amendments, so that office is the definitive source. Manufacturers, engineers, and contractors do not establish which code edition applies.

Question 4Electrical Code and Plan Review Fundamentals

What does the term "ampacity" describe?

  1. The interrupting rating of an overcurrent device
  2. The total resistance of a conductor measured end to end
  3. The voltage drop along a feeder under full load
  4. The maximum current a conductor can carry continuously under stated conditions without exceeding its temperature rating Correct answer.

Explanation

Ampacity is the current-carrying capacity of a conductor under specified conditions of use, limited by its insulation temperature rating. It is distinct from resistance, voltage drop, and device interrupting ratings.

Question 5Electrical Code and Plan Review Fundamentals

In plan review, what is the purpose of a load calculation for a dwelling service?

  1. To select the color coding of branch-circuit conductors
  2. To determine the number of receptacle outlets required in each room
  3. To size the service conductors and overcurrent protection for the expected demand Correct answer.
  4. To establish the grounding electrode conductor length

Explanation

Load calculations determine the calculated demand load used to size service equipment and feeders. Receptacle spacing, conductor color, and grounding conductor length are governed by separate code provisions.

Question 6Electrical Code and Plan Review Fundamentals

A reviewer sees a symbol on an electrical plan consisting of a circle with two parallel lines through it. This most commonly indicates which device?

  1. A duplex receptacle Correct answer.
  2. A single-pole switch
  3. A smoke detector
  4. A junction box

Explanation

Standard electrical symbols use a circle with two parallel lines to denote a duplex receptacle. Switches, junction boxes, and detectors use distinct symbols defined in the drawing legend.

Question 7Electrical Code and Plan Review Fundamentals

Which of the following best describes a "feeder" as defined in the electrical code?

  1. The grounding electrode conductor run to a rod
  2. The service-drop conductors from the utility pole
  3. The conductors between the last overcurrent device and the outlets served
  4. All circuit conductors between the service equipment and the final branch-circuit overcurrent device Correct answer.

Explanation

A feeder carries power from service equipment or a source to a final branch-circuit overcurrent protective device. Conductors downstream of that final device are branch-circuit conductors, and grounding and service-drop conductors are separately defined.

Question 8Electrical Code and Plan Review Fundamentals

A panel schedule on the drawings lists circuit breakers and their connected loads. What is the primary purpose of this schedule during plan review?

  1. To confirm the structural capacity of the panel mounting wall
  2. To verify circuit loading, breaker sizing, and balanced phase distribution Correct answer.
  3. To document the building's fire separation requirements
  4. To specify the paint finish for the electrical room

Explanation

Panel schedules let the reviewer check that each circuit's load is within the breaker and conductor rating and that phases are reasonably balanced. Fire separation, structural capacity, and finishes are outside the schedule's scope.

Question 9Electrical Code and Plan Review Fundamentals

A dwelling unit has a 3,000 VA general lighting load and small-appliance and laundry branch circuits. Which method category does the general lighting load fall under for service calculation?

  1. Special equipment load
  2. Fixed appliance load
  3. Largest motor load
  4. General lighting and receptacle load Correct answer.

Explanation

General lighting and general-use receptacle loads are calculated together as the general lighting load, with small-appliance and laundry circuits added per code demand rules. Motor, fixed appliance, and special equipment loads are separate categories.

Question 10Electrical Code and Plan Review Fundamentals

During review, a designer proposes a 15-ampere branch circuit feeding a bathroom receptacle outlet in a dwelling. How should the reviewer respond?

  1. Approve it only if a GFCI receptacle is installed
  2. Require a dedicated 30-ampere circuit
  3. Approve it because 15-ampere circuits are permitted anywhere in dwellings
  4. Require a 20-ampere branch circuit for the bathroom receptacle Correct answer.

Explanation

Bathroom receptacle outlets in dwelling units must be supplied by 20-ampere branch circuits. GFCI protection is also required, but it does not make a 15-ampere circuit acceptable.

Question 11Electrical Code and Plan Review Fundamentals

A plan shows a 200-ampere service with service conductors sized for the calculated load. Which document element should the reviewer check to confirm the service disconnect is properly rated?

  1. The fire alarm riser diagram
  2. The roof framing plan
  3. The service equipment schedule and one-line diagram Correct answer.
  4. The landscape plan

Explanation

Service equipment ratings and the electrical distribution arrangement appear on the service schedule and one-line diagram. Landscape, fire alarm, and roof plans do not establish service equipment ratings.

Question 12Electrical Code and Plan Review Fundamentals

A reviewer is checking working clearances at a panelboard. Which factor directly determines the minimum depth of the working space in front of the equipment?

  1. The number of circuits in the panel
  2. The color of the panel enclosure
  3. The voltage to ground and the conditions of exposure at the equipment Correct answer.
  4. The size of the branch-circuit breakers

Explanation

Working-space depth is based on the nominal voltage to ground and whether the equipment is exposed to grounded parts, live parts on the opposite side, or other conditions. Circuit count, enclosure color, and breaker size do not set the depth.

Question 13Electrical Code and Plan Review Fundamentals

A drawing note specifies that all 125-volt, 15- and 20-ampere receptacles in a commercial garage be GFCI protected. What is the reviewer's most appropriate action?

  1. Approve the note only if the receptacles are 30 amperes
  2. Delete the note because GFCI protection is never required in garages
  3. Verify the requirement matches the code location rules and confirm the protection is shown Correct answer.
  4. Require AFCI protection instead in all garage locations

Explanation

GFCI protection is required for many receptacle locations in garages and similar occupancies, so the reviewer confirms the note aligns with the applicable location rules. Deleting the note or substituting AFCI or a different ampere rating would not satisfy the requirement.

Question 14Electrical Code and Plan Review Fundamentals

A feeder supplies a subpanel in a detached structure. Which plan information is essential to verify overcurrent protection and conductor sizing for that feeder?

  1. The calculated load, conductor size, and feeder breaker rating Correct answer.
  2. The utility transformer's impedance
  3. The number of lighting fixtures in the main building
  4. The building's occupancy classification only

Explanation

Feeder conductor and overcurrent device sizing depend on the calculated load and the conductor ampacity. Occupancy classification, fixture counts in another building, and transformer impedance do not directly establish feeder sizing for the subpanel.

Question 15Electrical Code and Plan Review Fundamentals

A plan shows a 60-ampere, 240-volt single-phase feeder with 6 AWG copper conductors. The calculated load is 48 amperes. How should the reviewer evaluate the conductor ampacity relative to the load?

  1. The conductor must be sized for the breaker's interrupting rating
  2. The conductor must be sized at twice the calculated load
  3. The conductor must have an ampacity at least equal to the calculated load, so 6 AWG copper at its listed ampacity is checked against 48 amperes Correct answer.
  4. The conductor is always acceptable regardless of ampacity

Explanation

Feeder conductors must have an ampacity not less than the calculated load, subject to the applicable termination and adjustment rules. Ampacity is compared with the load, not doubled or matched to an interrupting rating.

Question 16Electrical Code and Plan Review Fundamentals

A plan reviewer notices that a grounding electrode system is shown with only a single ground rod. What should the reviewer confirm regarding the electrode?

  1. That the electrode's resistance to earth meets the code threshold, or that a supplemental electrode is provided Correct answer.
  2. That the rod is at least 20 feet long
  3. That the rod is connected to the neutral at each receptacle
  4. That the rod is painted to match the building

Explanation

A single rod must demonstrate a resistance to earth of 25 ohms or less, or a supplemental electrode must be added. Rod length, paint finish, and receptacle neutral connections are separate matters.

Question 17Electrical Code and Plan Review Fundamentals

During review of a commercial kitchen plan, the designer shows receptacle outlets on the countertop. Which protection requirement should the reviewer verify?

  1. Surge protection at each receptacle
  2. No protection is required for kitchen receptacles
  3. AFCI protection for all countertop receptacles
  4. GFCI protection for the countertop receptacles Correct answer.

Explanation

Receptacles serving countertops in commercial kitchens are among the locations requiring GFCI protection. AFCI, no protection, and point-of-use surge protection do not satisfy that requirement.

Question 18Electrical Code and Plan Review Fundamentals

A drawing shows a 3-phase, 4-wire panelboard with a 120/208-volt rating. What does the slash rating indicate?

  1. The panel can supply only 120-volt loads
  2. The panel requires a 208-ampere breaker
  3. The line-to-line voltage is 208 volts and the line-to-neutral voltage is 120 volts Correct answer.
  4. The panel is rated for 120 amperes and 208 amperes

Explanation

Slash voltage ratings state line-to-line voltage first and line-to-neutral voltage second, so 120/208 volts means 208 volts between phases and 120 volts to neutral. The numbers are voltages, not amperages, and the panel can serve both line-to-line and line-to-neutral loads.

Question 19Electrical Code and Plan Review Fundamentals

A plan reviewer is evaluating a proposed panel location in a hallway. Which clearance issue is most directly relevant to code compliance?

  1. Whether the hallway has a carpeted floor
  2. Whether the panel is mounted on a painted wall
  3. Whether the required working space in front of the panel is kept clear of storage and obstructions Correct answer.
  4. Whether the hallway has a window

Explanation

Electrical equipment must have dedicated working space kept clear of obstructions, so a hallway location must preserve that space. Windows, paint, and floor coverings are not the controlling clearance factors.

Question 20Electrical Code and Plan Review Fundamentals

A plan shows a 100-ampere panelboard fed by a 100-ampere breaker with conductors whose ampacity is 85 amperes. What is the reviewer's concern?

  1. The breaker is too small for the panel
  2. The conductors may be undersized relative to the overcurrent device and load Correct answer.
  3. The panelboard voltage rating is inadequate
  4. The conductors are oversized for the load

Explanation

Conductors must be protected against overcurrent in accordance with their ampacity, so a 100-ampere breaker on 85-ampere conductors is a potential mismatch. Breaker-to-panel and voltage ratings are separate checks, and 85 amperes is not oversized for a 100-ampere device.

Question 21Electrical Code and Plan Review Fundamentals

A drawing legend uses a symbol described as a solid triangle. In electrical plan conventions, what does this most often represent?

  1. A panelboard
  2. A luminaire
  3. A receptacle outlet Correct answer.
  4. A telephone outlet

Explanation

A solid triangle is a common convention for a receptacle outlet on electrical plans, though the drawing legend always governs. Luminaires, panelboards, and telephone outlets use other symbols.

Question 22Electrical Code and Plan Review Fundamentals

A designer proposes using the optional calculation method for a single-family dwelling service. What is a key condition the reviewer should confirm before accepting it?

  1. The dwelling has at least two panelboards
  2. The service is 400 amperes or larger
  3. The dwelling has no electric range
  4. The dwelling meets the eligibility criteria for the optional method, such as being a single dwelling unit Correct answer.

Explanation

The optional calculation method is limited to dwelling units meeting specified eligibility conditions, such as a single dwelling unit supplied by a single set of service conductors. Absence of a range, a minimum service size, or multiple panelboards are not conditions of eligibility.

Question 23Electrical Code and Plan Review Fundamentals

A plan reviewer must evaluate whether a feeder's overcurrent device is properly coordinated with downstream branch-circuit protection in a building with a large motor load. Which concept is central to this review?

  1. Selective coordination so that the device nearest the fault opens first Correct answer.
  2. Sizing all devices to the same ampere rating
  3. Eliminating all downstream overcurrent devices
  4. Using only fuses throughout the system

Explanation

Coordination ensures the protective device closest to a fault clears it, limiting outage scope, which is especially important with large motor contributions. Identical ratings, fuse-only designs, and removal of downstream devices do not achieve coordination.

Question 24Electrical Code and Plan Review Fundamentals

A plan shows a feeder passing through a building with significant ambient temperature above the conductor's rating basis. How should the reviewer treat the conductor ampacity?

  1. Apply the applicable correction factors, which may reduce the allowable ampacity below the tabulated value Correct answer.
  2. Increase the ampacity because heat improves conductivity
  3. Use the breaker rating as the ampacity
  4. Ignore ambient temperature because ampacity tables are absolute

Explanation

Ampacity tables are based on specified conditions, so correction factors must be applied for higher ambient temperatures and other conditions of use. Tables are not absolute, heat does not improve ampacity, and breaker ratings are not conductor ampacities.

Question 25Electrical Code and Plan Review Fundamentals

A plan reviewer is assessing a service with a calculated load of 180 amperes and a proposed 200-ampere service. Which additional check is most appropriate for the service conductors?

  1. Confirm the meter is rated for 240 volts only
  2. Confirm the conductors are the same color as the panel
  3. Confirm the service drop is at least 100 feet long
  4. Confirm the conductors' ampacity, after any adjustment or correction, is at least the calculated load and protected by the service device Correct answer.

Explanation

Service conductors must have adequate ampacity for the calculated load and be protected by the service overcurrent device, considering any adjustment or correction factors. Color, drop length, and meter voltage rating are not the controlling checks.

Question 26Electrical Code and Plan Review Fundamentals

On a set of electrical plans, a note specifies the available fault current at the service. Which document element is most directly verified against this value?

  1. The ampacity of the grounding electrode conductor
  2. The interrupting rating of the service overcurrent device Correct answer.
  3. The voltage drop along the branch circuits
  4. The size of the equipment grounding conductor

Explanation

Overcurrent protective devices must have an interrupting rating at least equal to the available fault current at their line terminals. The available fault current note on the plans is therefore checked against the rating of the service device. Conductor ampacity, voltage drop, and grounding conductor sizing are unrelated to fault-current interrupting capability.

Question 27Electrical Code and Plan Review Fundamentals

A plan reviewer sees that a branch circuit is shown with a slash mark through one of the conductor lines in a multiwire cable symbol. What does this convention typically indicate?

  1. The conductors are aluminum rather than copper
  2. The cable is shielded against electromagnetic interference
  3. The circuit is a dedicated single-pole circuit
  4. The conductor count includes a neutral in a shared circuit Correct answer.

Explanation

Slash marks through a cable line denote the number of conductors, and a shared neutral in a multiwire branch circuit is commonly shown this way. The marking conveys conductor count, not material or shielding. Dedicated single-pole circuits would not require a slash notation.

Question 28Electrical Code and Plan Review Fundamentals

A designer shows a 20-ampere branch circuit supplying a single receptacle outlet in a commercial occupancy. Which plan information is required to confirm the receptacle rating is adequate?

  1. The mounting height above the floor
  2. The manufacturer of the receptacle
  3. The ampere and voltage rating of the receptacle shown Correct answer.
  4. The color of the receptacle faceplate

Explanation

A single receptacle on an individual branch circuit must have an ampere rating not less than the branch circuit rating. The reviewer must therefore see the receptacle's ampere and voltage rating on the plan. Height, color, and manufacturer do not affect code compliance.

Question 29Electrical Code and Plan Review Fundamentals

A plan shows a 240-volt, single-phase appliance branch circuit protected by a 30-ampere breaker with 10 AWG copper conductors. The appliance nameplate lists a minimum circuit ampacity of 24 amperes and a maximum overcurrent protection of 30 amperes. How should the reviewer treat this installation?

  1. It violates the code because the breaker exceeds the minimum circuit ampacity
  2. It violates the code because 10 AWG is too small for a 30-ampere circuit
  3. It requires derating because the appliance is a continuous load
  4. It complies because conductor ampacity and the device rating both meet the nameplate values Correct answer.

Explanation

The nameplate minimum circuit ampacity and maximum overcurrent protection govern the branch circuit. Conductors rated at least 24 amperes and a device not exceeding 30 amperes satisfy the listing instructions. A 10 AWG copper conductor with a 30-ampere device meets both values.

Question 30Electrical Code and Plan Review Fundamentals

A drawing schedule lists a panelboard with a bus rating of 225 amperes and a main breaker rated 200 amperes. What does the bus rating represent?

  1. The maximum continuous current the panelboard bus is listed to carry Correct answer.
  2. The available fault current at the panel
  3. The total connected load served by the panel
  4. The current at which the main breaker will trip

Explanation

The bus rating is the ampere rating the panelboard's busbars are listed to carry. The main breaker rating may be lower and sets the protection level. Connected load and available fault current are separate calculated or noted values.

Question 31Electrical Code and Plan Review Fundamentals

A plan reviewer is checking a feeder that will supply a panelboard in an area where the ambient temperature is expected to reach 50 degrees C. What effect should this have on the conductor sizing shown?

  1. The overcurrent device must be reduced in rating
  2. Conductors may be upsized only if voltage drop exceeds three percent
  3. No adjustment is needed if the conductors are copper
  4. Conductors must be derated using an ambient temperature correction factor Correct answer.

Explanation

Ampacities in the code tables are based on a reference ambient, and higher ambient temperatures require correction factors. The reviewer must confirm the designer applied the appropriate correction. Voltage drop and conductor material do not eliminate the temperature adjustment.

Question 32Electrical Code and Plan Review Fundamentals

During review, a designer proposes routing a feeder through a building using a wiring method not listed for the occupancy. What is the reviewer's most appropriate action?

  1. Require a code-compliant wiring method or documented approval before approval Correct answer.
  2. Approve the plan if the feeder is protected by a listed breaker
  3. Approve the plan because feeders are allowed in any raceway
  4. Require only that the feeder be labeled at both ends

Explanation

Wiring methods must be permitted for the occupancy and location where installed. A method not recognized for that use must be changed or justified through the applicable approval process. Breaker protection and labeling do not cure a prohibited wiring method.

Question 33Electrical Code and Plan Review Fundamentals

A plan shows a 480-volt, 3-phase motor branch circuit with a disconnect located 60 feet from the motor and not within sight. Which condition must be met for this arrangement to be acceptable?

  1. The motor must be rated for continuous duty
  2. The disconnect must be capable of being locked in the open position Correct answer.
  3. The circuit must include a shunt trip
  4. The disconnect must be a fused switch

Explanation

Where a motor disconnect is out of sight of the motor, the code generally requires the disconnect to be lockable in the open position. This allows servicing personnel to secure the circuit. Fusing, duty rating, and shunt tripping are not the governing requirement for this location.

Question 34Electrical Code and Plan Review Fundamentals

A plan reviewer notes that a feeder neutral is shown smaller than the ungrounded conductors on a 3-phase, 4-wire system serving nonlinear loads. What concern should be raised?

  1. Triplen harmonic currents may accumulate in the neutral and require a full-size neutral Correct answer.
  2. The neutral must be insulated with green identification
  3. The neutral must always be one size smaller than the phase conductors
  4. The feeder must be converted to a 3-wire system

Explanation

On 4-wire systems serving nonlinear loads, triplen harmonics can add in the neutral, so the neutral may need to be sized no smaller than the ungrounded conductors. The reviewer should flag the undersized neutral for harmonic-producing loads. Neutral sizing is not automatically one size smaller, and green identifies grounding conductors.

Question 35Electrical Code and Plan Review Fundamentals

A drawing shows a service with a calculated load of 150 amperes and a proposed 200-ampere service disconnect. Which statement best describes the reviewer's evaluation of the service rating?

  1. The service disconnect must exactly equal the calculated load
  2. The service rating is determined solely by the meter socket
  3. The service rating must be at least the calculated load and the conductors must be sized accordingly Correct answer.
  4. The service rating may be less than the calculated load if the utility approves

Explanation

The service equipment rating must be adequate for the calculated load, and service conductors must be sized to carry it. A rating larger than the calculated load is acceptable. Exact matching is not required, and utility approval does not override the code minimum.

Question 36Electrical Code and Plan Review Fundamentals

A plan shows a 120-volt, 20-ampere branch circuit in a dwelling unit supplying receptacle outlets in a garage. Which protection requirement should the reviewer confirm?

  1. AFCI protection for the receptacle outlets
  2. Neither GFCI nor AFCI protection
  3. Only surge protection
  4. GFCI protection for the receptacle outlets Correct answer.

Explanation

Receptacle outlets in dwelling-unit garages require ground-fault circuit-interrupter protection. The reviewer should confirm GFCI devices are shown. AFCI is not the specific requirement for garage receptacles, and surge protection does not substitute.

Question 37Electrical Code and Plan Review Fundamentals

A plan reviewer is examining a feeder tap where the tap conductors are 10 feet long and have an ampacity of one-third the rating of the upstream overcurrent device. Which condition must also be satisfied for this tap rule?

  1. The tap conductors must be installed in rigid metal conduit
  2. The tap conductors must be copper
  3. The tap must be made in a junction box with a cover
  4. The tap conductors must terminate in a device or panelboard with overcurrent protection sized for the tap Correct answer.

Explanation

Short feeder taps are permitted when the tap conductors terminate in an overcurrent device that limits the load to the tap ampacity, among other conditions. Raceway type, conductor material, and box covers are not the governing condition for this tap rule.

Question 38Electrical Code and Plan Review Fundamentals

A drawing legend indicates a symbol for a junction box with a note reading 'WP'. What does this most likely tell the reviewer?

  1. The box is a floor box
  2. The box is rated for wet locations Correct answer.
  3. The box is weatherproof only when painted
  4. The box is a wireway pull point

Explanation

'WP' is a common abbreviation for weatherproof or wet-location rated equipment. The reviewer should confirm the box is listed for the environment shown. It does not denote a pull point, floor box, or a paint-dependent rating.

Question 39Electrical Code and Plan Review Fundamentals

A plan shows a 3-phase, 4-wire, 120/208-volt panelboard with a slash rating. What does the slash rating indicate about the panelboard?

  1. It may only be used on a corner-grounded delta system
  2. It is limited to single-phase applications
  3. It requires a neutral disconnect
  4. It is rated for line-to-line voltage and for line-to-neutral voltage on the lower side of the slash Correct answer.

Explanation

A slash rating such as 120/208 volts means the equipment is rated for the higher line-to-line voltage and for the lower line-to-neutral voltage. It is not limited to single-phase use or corner-grounded systems. A neutral disconnect is a separate design question.

Question 40Electrical Code and Plan Review Fundamentals

A reviewer is checking a plan for a commercial building where a 60-ampere feeder supplies a subpanel. The plan shows 6 AWG copper conductors and a 70-ampere breaker. What is the reviewer's primary concern?

  1. The breaker rating exceeds the conductor ampacity shown Correct answer.
  2. The conductors are oversized for the load
  3. The subpanel requires a main breaker
  4. The feeder needs a separate grounding electrode

Explanation

The overcurrent device protecting a feeder must not exceed the ampacity of the conductors. A 70-ampere breaker on 6 AWG copper conductors, whose ampacity is lower, is a mismatch that must be corrected. Oversizing, subpanel mains, and grounding electrodes are separate considerations.

Question 41Electrical Code and Plan Review Fundamentals

A plan shows a 100-ampere panelboard fed by a 100-ampere breaker. The calculated load is 95 amperes. Which additional check is most important for the reviewer?

  1. That the branch circuits are all 20 amperes
  2. That the panelboard bus rating is at least 100 amperes Correct answer.
  3. That the panelboard has a copper bus
  4. That the panelboard is mounted at 48 inches

Explanation

The panelboard bus must be rated at least as high as the overcurrent device protecting it. Mounting height, branch-circuit ratings, and bus material are separate matters. The reviewer confirms the bus rating is adequate for the 100-ampere protection.

Question 42Electrical Code and Plan Review Fundamentals

A plan reviewer sees a note that all conductors in a raceway are 12 AWG THHN and there are 12 current-carrying conductors in the raceway. What should the reviewer verify regarding ampacity?

  1. That the conductors are derated only for voltage drop
  2. That no adjustment is required below 20 conductors
  3. That an adjustment factor for conductor count has been applied Correct answer.
  4. That the neutral is counted as a current-carrying conductor in all cases

Explanation

When more than three current-carrying conductors share a raceway, ampacity adjustment factors apply. The reviewer should confirm the designer applied the correct factor for 12 conductors. Adjustment is required well below 20 conductors, and neutral counting depends on the system and load characteristics.

Question 43Electrical Code and Plan Review Fundamentals

A plan shows a grounding electrode conductor connected to a metal underground water pipe. What additional requirement should the reviewer confirm?

  1. That the water pipe is less than 10 feet in contact with earth
  2. That the water pipe is painted
  3. That a supplemental electrode is provided because the water pipe alone may not be sufficient Correct answer.
  4. That the grounding electrode conductor is bare copper only

Explanation

A metal underground water pipe is a grounding electrode, but because it may be replaced or altered, a supplemental electrode is generally required. Paint, conductor finish, and a minimum earth contact length do not replace the supplemental electrode requirement.

Question 44Electrical Code and Plan Review Fundamentals

A reviewer is evaluating a plan where a 20-ampere branch circuit supplies a continuous load of 16 amperes. Which conclusion is correct?

  1. The circuit is adequate if the breaker is a listed GFCI type
  2. The circuit is adequate because 16 amperes is below 20 amperes
  3. The circuit requires a 30-ampere breaker
  4. The circuit is not adequate because the continuous load exceeds 80 percent of the rating Correct answer.

Explanation

Branch circuits supplying continuous loads must be sized so the load does not exceed 80 percent of the circuit rating unless the assembly is listed for 100 percent. For a 20-ampere circuit, 80 percent is 16 amperes, so a 16-ampere continuous load is at the limit and a higher load would be noncompliant. The reviewer should confirm the load does not exceed that threshold.

Question 45Electrical Code and Plan Review Fundamentals

A plan shows a 240-volt, 50-ampere receptacle for an electric range in a dwelling unit. Which plan element is most important for the reviewer to verify?

  1. The receptacle is GFCI protected
  2. The range is on a dedicated 120-volt circuit
  3. The branch-circuit conductor size and the receptacle rating match the range nameplate Correct answer.
  4. The receptacle is mounted at 12 inches

Explanation

For a specific appliance, the branch-circuit conductors and receptacle must be sized to the appliance nameplate and the circuit rating. GFCI protection, mounting height, and voltage are separate considerations. The reviewer confirms the conductor and receptacle ratings match the range requirements.

Question 46Electrical Code and Plan Review Fundamentals

A plan reviewer notices that a panelboard is shown in a location with a 30-inch-wide clear space but a door that swings into the working space. What is the reviewer's concern?

  1. The door swing may encroach on the required working space Correct answer.
  2. The 30-inch width is always insufficient
  3. The door must be removed
  4. The panelboard must be relocated to a hallway

Explanation

Working space in front of electrical equipment must be kept clear, and doors that swing into that space can create an obstruction. The reviewer should confirm the door swing does not reduce the required clear working space. The 30-inch width is a standard minimum, and relocation or door removal is not automatically required.

Question 47Electrical Code and Plan Review Fundamentals

A drawing shows a feeder installed in a raceway passing through a fire-rated wall. What should the reviewer confirm about the penetration?

  1. That the raceway is painted red
  2. That the raceway is steel
  3. That the feeder is de-energized during construction
  4. That an approved firestop system is specified Correct answer.

Explanation

Penetrations of fire-rated assemblies must be protected with an approved firestop system. The reviewer should confirm the plan specifies a listed firestop method. Paint color, raceway material, and construction energization are not the governing requirement.

Question 48Electrical Code and Plan Review Fundamentals

A reviewer is checking a plan for a 480-volt, 3-phase feeder supplying a panelboard with a calculated load of 250 amperes. The plan shows 250 kcmil copper conductors and a 300-ampere breaker. What is the primary concern?

  1. The breaker rating may exceed the conductor ampacity and must be verified Correct answer.
  2. The panelboard requires a 400-ampere bus
  3. The feeder needs a neutral
  4. The conductors are too large for the load

Explanation

The overcurrent device protecting the feeder must not exceed the conductor ampacity. The reviewer must confirm that the 250 kcmil copper conductors have an ampacity at least equal to the 300-ampere breaker, considering termination limits and adjustment factors. Conductor oversizing, bus rating, and neutral requirements are separate checks.

Question 49Electrical Code and Plan Review Fundamentals

A plan legend shows a symbol for a receptacle with a 'GFI' label. In which of the following dwelling locations is that protection required on the plan?

  1. Dining room receptacle outlets
  2. Bedroom receptacle outlets
  3. Living room receptacle outlets
  4. Unfinished basement receptacle outlets Correct answer.

Explanation

Receptacle outlets in unfinished basements of dwelling units require ground-fault circuit-interrupter protection. Bedroom, living room, and dining room receptacles are generally subject to arc-fault protection instead. The reviewer confirms GFCI is shown where the code requires it.

Question 50Electrical Code and Plan Review Fundamentals

A plan shows a service disconnect with a grounded conductor brought to the service equipment and a grounding electrode conductor connected to the enclosure. The reviewer should confirm that the grounded conductor and equipment grounding conductors are separated where?

  1. At all downstream panelboards and equipment Correct answer.
  2. Only at the meter socket
  3. Only at the utility transformer
  4. Nowhere, because they must remain bonded throughout

Explanation

The main bonding jumper connects the grounded conductor and equipment grounding conductors only at the service. Downstream of the service, they must be separated to avoid parallel return paths. Bonding them again at subpanels would be a violation.