Electrical Plans Examiner - E3 National Certification Exam
Total 500 plus [Questions & Answers with Full Explanations]
Question 1:
When reviewing electrical service plans, which factor is most critical for determining the
required conductor ampacity?
A. Conductor color
B. Load calculation
C. Service panel location
D. Conductor insulation type
Correct Answer: B
Explanation: The conductor ampacity must support the calculated load (demand) on the service.
A proper load calculation ensures that the conductors are sized to handle the expected current.
Question 2:
Which of the following is not a typical consideration when inspecting service conductors?
A. Conductor material
B. Conductor ampacity
C. Clearance from combustible materials
D. The phase rotation sequence
Correct Answer: D
Explanation: While conductor material, ampacity, and clearances are key factors, the phase
rotation sequence is not directly related to service conductor size and rating inspections.
Question 3:
When verifying service conductor clearances, the inspector should check that the conductors:
A. Are colored per the code
B. Are spaced adequately from grounded surfaces
C. Have minimum conductor ampacity
D. Are bundled for ease of installation
Correct Answer: B
Explanation: Adequate clearance from grounded or conductive surfaces helps ensure safety and
minimizes the risk of electrical faults.
,Question 4:
A service entrance conductor’s rating is primarily based on:
A. The length of the conductor run
B. The maximum load the service is expected to carry
C. The ambient temperature alone
D. The type of building served
Correct Answer: B
Explanation: The conductor must be capable of carrying the maximum load (current) expected
under operating conditions. The load calculation is the primary basis for determining the proper
conductor size.
Question 5:
Which of the following best describes “ampacity” in the context of service conductors?
A. The maximum voltage a conductor can handle
B. The current-carrying capacity of a conductor
C. The resistance level within a conductor
D. The physical size of the conductor
Correct Answer: B
Explanation: Ampacity refers to the maximum amount of current a conductor can carry
continuously under the conditions of use without exceeding its temperature rating.
Question 6:
When inspecting the service size on a set of electrical plans, the inspector must verify that the
conductor rating is:
A. Exactly the same as the load calculation
B. Equal to or greater than the calculated load requirements
C. Lower than the calculated load for energy efficiency
D. Determined solely by the conductor insulation rating
Correct Answer: B
Explanation: The conductor’s rating must meet or exceed the load requirements to ensure safe
and efficient operation.
Question 7:
Which aspect of service equipment is directly verified by checking the conductor ampacity?
A. Overcurrent protection coordination
B. Adequacy of conductor size relative to expected load
,C. The color coding of wiring
D. The mechanical support of the service mast
Correct Answer: B
Explanation: Verifying ampacity ensures that the conductor size is adequate to safely carry the
expected load without overheating.
Question 8:
A plan shows a service entrance conductor with an ampacity of 200 A. If the calculated load is
180 A, what is the inspector most likely to conclude?
A. The conductor is undersized.
B. The conductor is adequately sized.
C. The conductor is oversized.
D. The calculation must be redone.
Correct Answer: B
Explanation: Since the conductor ampacity (200 A) exceeds the calculated load (180 A), the
conductor is adequately sized according to typical safety margins.
Question 9:
In determining service size, which document or standard is most often referenced for conductor
ampacity requirements?
A. National Electrical Code (NEC)
B. International Building Code (IBC)
C. Underwriters Laboratories (UL) listing
D. Occupational Safety and Health Administration (OSHA) guidelines
Correct Answer: A
Explanation: The National Electrical Code (NEC) provides the rules and tables used to
determine the proper ampacity and sizing of conductors for various applications.
Question 10:
When checking conductor materials on a plan, which of the following is most critical?
A. The aesthetic finish of the conductor
B. The compatibility of the material with the expected current load
C. The manufacturer’s logo
D. The installation method (overhead vs. underground)
Correct Answer: B
Explanation: The conductor material must be compatible with the load requirements and
, environmental conditions. Common materials like copper and aluminum have different ampacity
characteristics.
Question 11:
Service conductor clearances are important to ensure:
A. Minimal electromagnetic interference
B. Adequate heat dissipation and safety from accidental contact
C. Easier cable identification
D. Cost savings in installation
Correct Answer: B
Explanation: Adequate clearances help prevent overheating and reduce the risk of accidental
contact with energized parts.
Question 12:
If a plan indicates a service conductor installed in a location with higher ambient temperatures,
what adjustment is most likely required?
A. A decrease in conductor size
B. No adjustment is needed
C. An increase in conductor size to compensate for reduced ampacity
D. A change in conductor color
Correct Answer: C
Explanation: Higher ambient temperatures can reduce the ampacity of a conductor; therefore, a
larger conductor may be needed to safely carry the same load.
Question 13:
Which item is typically included on an electrical plan to indicate the service rating?
A. The conductor’s manufacturing date
B. The calculated load (in amperes) and conductor size
C. The contractor’s logo
D. The installation instructions for the panelboard
Correct Answer: B
Explanation: Electrical plans usually indicate the service load (in amperes) and the conductor
size chosen based on that load calculation.
Total 500 plus [Questions & Answers with Full Explanations]
Question 1:
When reviewing electrical service plans, which factor is most critical for determining the
required conductor ampacity?
A. Conductor color
B. Load calculation
C. Service panel location
D. Conductor insulation type
Correct Answer: B
Explanation: The conductor ampacity must support the calculated load (demand) on the service.
A proper load calculation ensures that the conductors are sized to handle the expected current.
Question 2:
Which of the following is not a typical consideration when inspecting service conductors?
A. Conductor material
B. Conductor ampacity
C. Clearance from combustible materials
D. The phase rotation sequence
Correct Answer: D
Explanation: While conductor material, ampacity, and clearances are key factors, the phase
rotation sequence is not directly related to service conductor size and rating inspections.
Question 3:
When verifying service conductor clearances, the inspector should check that the conductors:
A. Are colored per the code
B. Are spaced adequately from grounded surfaces
C. Have minimum conductor ampacity
D. Are bundled for ease of installation
Correct Answer: B
Explanation: Adequate clearance from grounded or conductive surfaces helps ensure safety and
minimizes the risk of electrical faults.
,Question 4:
A service entrance conductor’s rating is primarily based on:
A. The length of the conductor run
B. The maximum load the service is expected to carry
C. The ambient temperature alone
D. The type of building served
Correct Answer: B
Explanation: The conductor must be capable of carrying the maximum load (current) expected
under operating conditions. The load calculation is the primary basis for determining the proper
conductor size.
Question 5:
Which of the following best describes “ampacity” in the context of service conductors?
A. The maximum voltage a conductor can handle
B. The current-carrying capacity of a conductor
C. The resistance level within a conductor
D. The physical size of the conductor
Correct Answer: B
Explanation: Ampacity refers to the maximum amount of current a conductor can carry
continuously under the conditions of use without exceeding its temperature rating.
Question 6:
When inspecting the service size on a set of electrical plans, the inspector must verify that the
conductor rating is:
A. Exactly the same as the load calculation
B. Equal to or greater than the calculated load requirements
C. Lower than the calculated load for energy efficiency
D. Determined solely by the conductor insulation rating
Correct Answer: B
Explanation: The conductor’s rating must meet or exceed the load requirements to ensure safe
and efficient operation.
Question 7:
Which aspect of service equipment is directly verified by checking the conductor ampacity?
A. Overcurrent protection coordination
B. Adequacy of conductor size relative to expected load
,C. The color coding of wiring
D. The mechanical support of the service mast
Correct Answer: B
Explanation: Verifying ampacity ensures that the conductor size is adequate to safely carry the
expected load without overheating.
Question 8:
A plan shows a service entrance conductor with an ampacity of 200 A. If the calculated load is
180 A, what is the inspector most likely to conclude?
A. The conductor is undersized.
B. The conductor is adequately sized.
C. The conductor is oversized.
D. The calculation must be redone.
Correct Answer: B
Explanation: Since the conductor ampacity (200 A) exceeds the calculated load (180 A), the
conductor is adequately sized according to typical safety margins.
Question 9:
In determining service size, which document or standard is most often referenced for conductor
ampacity requirements?
A. National Electrical Code (NEC)
B. International Building Code (IBC)
C. Underwriters Laboratories (UL) listing
D. Occupational Safety and Health Administration (OSHA) guidelines
Correct Answer: A
Explanation: The National Electrical Code (NEC) provides the rules and tables used to
determine the proper ampacity and sizing of conductors for various applications.
Question 10:
When checking conductor materials on a plan, which of the following is most critical?
A. The aesthetic finish of the conductor
B. The compatibility of the material with the expected current load
C. The manufacturer’s logo
D. The installation method (overhead vs. underground)
Correct Answer: B
Explanation: The conductor material must be compatible with the load requirements and
, environmental conditions. Common materials like copper and aluminum have different ampacity
characteristics.
Question 11:
Service conductor clearances are important to ensure:
A. Minimal electromagnetic interference
B. Adequate heat dissipation and safety from accidental contact
C. Easier cable identification
D. Cost savings in installation
Correct Answer: B
Explanation: Adequate clearances help prevent overheating and reduce the risk of accidental
contact with energized parts.
Question 12:
If a plan indicates a service conductor installed in a location with higher ambient temperatures,
what adjustment is most likely required?
A. A decrease in conductor size
B. No adjustment is needed
C. An increase in conductor size to compensate for reduced ampacity
D. A change in conductor color
Correct Answer: C
Explanation: Higher ambient temperatures can reduce the ampacity of a conductor; therefore, a
larger conductor may be needed to safely carry the same load.
Question 13:
Which item is typically included on an electrical plan to indicate the service rating?
A. The conductor’s manufacturing date
B. The calculated load (in amperes) and conductor size
C. The contractor’s logo
D. The installation instructions for the panelboard
Correct Answer: B
Explanation: Electrical plans usually indicate the service load (in amperes) and the conductor
size chosen based on that load calculation.
