ICC COMMERCIAL ELECTRICAL
INSPECTOR EXAM (E2)
COMPLETE PRACTICE EXAM
LATEST MOCK PRACTICE SET
110 Questions with Answers and Detailed Rationales
100 PERCENT GUARANTEED PASS
INSTANT DOWNLOAD ANSWERS INCLUDED
IMPORTANCE OF THIS DOCUMENT
This comprehensive examination preparation guide has been meticulously developed to help you succeed in the
ICC COMMERCIAL ELECTRICAL INSPECTOR EXAM (E2) COMPLETE PRACTICE EXAM QUESTIONS WITH
DETAILED SOLUTIONS BASED ON NFPA 70 (NEC 2023) | LATEST UPDATE 2026/2027. It contains 110
carefully selected questions that reflect the most current exam content and testing strategies. Each question is
accompanied by a correct answer and a detailed rationale that explains the underlying pathophysiology,
pharmacology, or clinical reasoning.
Self-Assessment – Test your knowledge and Exam Preparation – Familiarize yourself with the
identify areas requiring further question format and content
study areas
Concept Reinforcement – Deepen your Confidence Building – Develop test-taking
understanding through strategies and reduce
evidence-based exam anxiety
rationales
Time Management – Practice answering
questions under simulated
exam conditions
Review Summary 110 Questions
Foundations - Application - ICC Commercial Electrical Inspector E2 Complete WITH Detailed Solutions
Based ON NFPA 70 NEC 2023 Update 2026/2027 ICC Commercial Electrical Inspector E2 NFPA 70 NEC
2023 Graduate / Professional Certification
All answers with rationales
,Table of Contents
Section A - General Requirements Section B - Wiring AND Protection
Article 90 100 110 Articles 200-285
Questions 1 to 28 Questions 29 to 56
Section C - Wiring Methods AND Section D - Equipment FOR General
Materials Articles 300-392 USE Articles 400-490
Questions 57 to 84 Questions 85 to 110
,Section A - General Requirements Article 90 100 110
Q1.
A commercial building has a 120/208V, 3-phase, 4-wire service. The calculated load is 400
kVA. The service entrance conductors are parallel 500 kcmil copper in separate conduits.
The inspector finds that the equipment grounding conductor (EGC) in each conduit is
sized at 1/0 AWG copper. Is this installation compliant with NEC 2023?
A. Yes, because 1/0 AWG is the minimum B. No, because the EGC must be sized per
EGC size for 500 kcmil phase conductors 250.66 based on the service entrance
per Table 250.122. conductor size.
C. No, because when paralleling D. Yes, because the EGC is sized per
conductors, a single full-size EGC must be 250.102(C)(1) for parallel conductors.
installed in each conduit, sized per 250.122
based on the overcurrent device rating.
Correct: C - No, because when paralleling conductors, a single full-size EGC must be
installed in each conduit, sized per 250.122 based on the overcurrent device rating.
Rationale:Per NEC 250.122(F), when paralleling conductors in multiple raceways, an EGC
must be installed in each raceway, sized per 250.122 based on the rating of the overcurrent
device protecting the circuit. The overcurrent device for a 400 kVA service at 208V is typically
1200A, requiring a 1/0 AWG copper EGC per Table 250.122. However, the inspector must
verify the actual overcurrent device rating. Option C correctly identifies the sizing rule. Option
A incorrectly references Table 250.122 without considering the overcurrent device rating.
Option B incorrectly applies 250.66 (grounding electrode conductor). Option D misapplies
250.102(C)(1) which is for bonding jumpers.
Q2.
In a commercial kitchen, a 50A, 208V single-phase range is supplied by a 6/3 NM cable
with a bare equipment grounding conductor. The cable passes through a floor that
separates a dry storage area from the kitchen. The inspector notes that the cable is not
protected where it penetrates the floor. Which code section applies?
A. 300.4 - Protection against physical B. 334.15 - Exposed work
damage
C. 300.22 - Wiring in ducts, plenums, and D. 334.30 - Securing and supporting
other air-handling spaces
Correct: A - 300.4 - Protection against physical damage
Page 3
, Section A - General Requirements Article 90 100 110
Rationale: NEC 300.4 requires protection for cables where they pass through floors, to
prevent physical damage from foot traffic or equipment. NM cable through a floor must be
protected in a listed conduit or raceway. Option A directly addresses this. Option B (334.15)
deals with NM cable in exposed locations but not specifically floor penetrations. Option C
(300.22) is for air-handling spaces. Option D (334.30) is about securing and supporting, not
protection.
Q3.
A commercial occupancy has a 400A, 120/208V, 3-phase, 4-wire service. The service
disconnect is a fused switch with 400A fuses. The inspector finds that the grounding
electrode conductor (GEC) is connected to the neutral bus in the service equipment and
runs to a concrete-encased electrode. The GEC is 2 AWG copper. Is this compliant?
A. Yes, because 2 AWG copper meets the B. No, because the GEC must be sized per
minimum size per Table 250.66 for a 400A 250.66 based on the largest ungrounded
service. service conductor.
C. No, because the GEC must be D. Yes, because the GEC is sized per
connected to the grounding electrode before 250.66 and the connection to the neutral is
the service disconnect. permitted per 250.24(A)(4).
Correct: B - No, because the GEC must be sized per 250.66 based on the largest
ungrounded service conductor.
Rationale:Per NEC 250.66, the GEC must be sized based on the size of the largest
ungrounded service conductor. For a 400A service, the phase conductors are typically 600
kcmil copper or 750 kcmil aluminum, requiring a GEC of 1/0 AWG copper or 3/0 AWG
aluminum per Table 250.66. A 2 AWG copper GEC is too small. Option A incorrectly assumes
Table 250.66 is based on service rating. Option C is false because the GEC can terminate at
the service disconnect. Option D is incorrect because the GEC is undersized.
Q4.
A commercial building has a 150 kVA, 480V to 208Y/120V transformer. The secondary
conductors are 4/0 AWG copper in a raceway. The inspector must verify the bonding
jumper size on the secondary side. Using Table 250.102(C)(1), what is the minimum size
copper bonding jumper?
A. 1/0 AWG B. 2/0 AWG
C. 3/0 AWG D. 4/0 AWG
Correct: C - 3/0 AWG
Page 4
INSPECTOR EXAM (E2)
COMPLETE PRACTICE EXAM
LATEST MOCK PRACTICE SET
110 Questions with Answers and Detailed Rationales
100 PERCENT GUARANTEED PASS
INSTANT DOWNLOAD ANSWERS INCLUDED
IMPORTANCE OF THIS DOCUMENT
This comprehensive examination preparation guide has been meticulously developed to help you succeed in the
ICC COMMERCIAL ELECTRICAL INSPECTOR EXAM (E2) COMPLETE PRACTICE EXAM QUESTIONS WITH
DETAILED SOLUTIONS BASED ON NFPA 70 (NEC 2023) | LATEST UPDATE 2026/2027. It contains 110
carefully selected questions that reflect the most current exam content and testing strategies. Each question is
accompanied by a correct answer and a detailed rationale that explains the underlying pathophysiology,
pharmacology, or clinical reasoning.
Self-Assessment – Test your knowledge and Exam Preparation – Familiarize yourself with the
identify areas requiring further question format and content
study areas
Concept Reinforcement – Deepen your Confidence Building – Develop test-taking
understanding through strategies and reduce
evidence-based exam anxiety
rationales
Time Management – Practice answering
questions under simulated
exam conditions
Review Summary 110 Questions
Foundations - Application - ICC Commercial Electrical Inspector E2 Complete WITH Detailed Solutions
Based ON NFPA 70 NEC 2023 Update 2026/2027 ICC Commercial Electrical Inspector E2 NFPA 70 NEC
2023 Graduate / Professional Certification
All answers with rationales
,Table of Contents
Section A - General Requirements Section B - Wiring AND Protection
Article 90 100 110 Articles 200-285
Questions 1 to 28 Questions 29 to 56
Section C - Wiring Methods AND Section D - Equipment FOR General
Materials Articles 300-392 USE Articles 400-490
Questions 57 to 84 Questions 85 to 110
,Section A - General Requirements Article 90 100 110
Q1.
A commercial building has a 120/208V, 3-phase, 4-wire service. The calculated load is 400
kVA. The service entrance conductors are parallel 500 kcmil copper in separate conduits.
The inspector finds that the equipment grounding conductor (EGC) in each conduit is
sized at 1/0 AWG copper. Is this installation compliant with NEC 2023?
A. Yes, because 1/0 AWG is the minimum B. No, because the EGC must be sized per
EGC size for 500 kcmil phase conductors 250.66 based on the service entrance
per Table 250.122. conductor size.
C. No, because when paralleling D. Yes, because the EGC is sized per
conductors, a single full-size EGC must be 250.102(C)(1) for parallel conductors.
installed in each conduit, sized per 250.122
based on the overcurrent device rating.
Correct: C - No, because when paralleling conductors, a single full-size EGC must be
installed in each conduit, sized per 250.122 based on the overcurrent device rating.
Rationale:Per NEC 250.122(F), when paralleling conductors in multiple raceways, an EGC
must be installed in each raceway, sized per 250.122 based on the rating of the overcurrent
device protecting the circuit. The overcurrent device for a 400 kVA service at 208V is typically
1200A, requiring a 1/0 AWG copper EGC per Table 250.122. However, the inspector must
verify the actual overcurrent device rating. Option C correctly identifies the sizing rule. Option
A incorrectly references Table 250.122 without considering the overcurrent device rating.
Option B incorrectly applies 250.66 (grounding electrode conductor). Option D misapplies
250.102(C)(1) which is for bonding jumpers.
Q2.
In a commercial kitchen, a 50A, 208V single-phase range is supplied by a 6/3 NM cable
with a bare equipment grounding conductor. The cable passes through a floor that
separates a dry storage area from the kitchen. The inspector notes that the cable is not
protected where it penetrates the floor. Which code section applies?
A. 300.4 - Protection against physical B. 334.15 - Exposed work
damage
C. 300.22 - Wiring in ducts, plenums, and D. 334.30 - Securing and supporting
other air-handling spaces
Correct: A - 300.4 - Protection against physical damage
Page 3
, Section A - General Requirements Article 90 100 110
Rationale: NEC 300.4 requires protection for cables where they pass through floors, to
prevent physical damage from foot traffic or equipment. NM cable through a floor must be
protected in a listed conduit or raceway. Option A directly addresses this. Option B (334.15)
deals with NM cable in exposed locations but not specifically floor penetrations. Option C
(300.22) is for air-handling spaces. Option D (334.30) is about securing and supporting, not
protection.
Q3.
A commercial occupancy has a 400A, 120/208V, 3-phase, 4-wire service. The service
disconnect is a fused switch with 400A fuses. The inspector finds that the grounding
electrode conductor (GEC) is connected to the neutral bus in the service equipment and
runs to a concrete-encased electrode. The GEC is 2 AWG copper. Is this compliant?
A. Yes, because 2 AWG copper meets the B. No, because the GEC must be sized per
minimum size per Table 250.66 for a 400A 250.66 based on the largest ungrounded
service. service conductor.
C. No, because the GEC must be D. Yes, because the GEC is sized per
connected to the grounding electrode before 250.66 and the connection to the neutral is
the service disconnect. permitted per 250.24(A)(4).
Correct: B - No, because the GEC must be sized per 250.66 based on the largest
ungrounded service conductor.
Rationale:Per NEC 250.66, the GEC must be sized based on the size of the largest
ungrounded service conductor. For a 400A service, the phase conductors are typically 600
kcmil copper or 750 kcmil aluminum, requiring a GEC of 1/0 AWG copper or 3/0 AWG
aluminum per Table 250.66. A 2 AWG copper GEC is too small. Option A incorrectly assumes
Table 250.66 is based on service rating. Option C is false because the GEC can terminate at
the service disconnect. Option D is incorrect because the GEC is undersized.
Q4.
A commercial building has a 150 kVA, 480V to 208Y/120V transformer. The secondary
conductors are 4/0 AWG copper in a raceway. The inspector must verify the bonding
jumper size on the secondary side. Using Table 250.102(C)(1), what is the minimum size
copper bonding jumper?
A. 1/0 AWG B. 2/0 AWG
C. 3/0 AWG D. 4/0 AWG
Correct: C - 3/0 AWG
Page 4
