Home Inspection Electrical Exam Prep Document | 2026/2027
Edition | 250 Verified Questions
Home Inspection Electrical Exam 2026-2027 Questions and Answers Already Graded A+. 100% Verified Solutions |
Updated Per Latest Guidelines | Graded A+
This comprehensive exam preparation document contains 250 verified questions and answers covering
all major topics in home inspection electrical systems. Designed for the 2026/2027 academic year, it
ensures you are fully prepared for the electrical portion of the home inspection licensing exam. Each
question is graded A+ with correct answers and detailed rationales to reinforce learning. Updated to
reflect the latest National Electrical Code (NEC) and industry standards.
Key Features:
Electrical system components and terminology
Service entrance and panel inspection
Wiring methods and materials
Overcurrent protection and grounding
Outlet, switch, and fixture inspection
Safety practices and code compliance
Updates for 2026:
- Updated to reflect 2026 NEC changes
- Added questions on AFCI/GFCI requirements
- Revised rationales for clarity and accuracy
- Included new scenarios on solar and EV charging systems
- Enhanced distractor explanations for common mistakes
Abstract:
This exam preparation document provides a rigorous review of electrical systems as they pertain to home
inspections. It covers the fundamental principles of electricity, service equipment, distribution panels, wiring types,
and safety devices. Special emphasis is placed on identifying defects, code violations, and hazards commonly found
in residential properties. The 250 questions are designed to mirror the format and difficulty of the actual licensing
exam, with each answer accompanied by a thorough rationale. Updated for 2026, this resource incorporates the
latest National Electrical Code revisions and emerging technologies such as photovoltaic systems and electric
vehicle supply equipment. By mastering this content, candidates will be well-equipped to pass the electrical section
of the home inspection exam with confidence.
Keywords:
home inspection electrical, NEC 2026, electrical exam prep, residential wiring, service panel inspection,
grounding and bonding, AFCI/GFCI, code compliance
Answer Format:
Each question is followed by the correct answer and a detailed rationale explaining why it is correct. Incorrect
options are also discussed to clarify common misconceptions, ensuring a comprehensive understanding of the
material.
Compliance Checklist:
All questions align with 2026 NEC requirements
Answers verified by licensed home inspectors
Covers all major electrical inspection topics
Page 1
, Includes code references for each answer
Updated for current exam standards
Suitable for both initial certification and recertification
Content Area Overview:
Content Area Questions Key Topics Weight
Electrical Fundamentals 1-40 Ohm's law, power calculations, AC/DC 16%
basics, electrical units
Service Entrance and Panels 41-80 Service drop, meter, main disconnect, 16%
panelboards, overcurrent protection
Wiring Methods and Materials 81-120 NM cable, conduit, wire types, ampacity, 16%
derating
Grounding and Bonding 121-160 Grounding electrodes, bonding jumpers, 16%
equipment grounding, system grounding
Outlets, Switches, and Fixtures 161-200 Receptacles, switches, lighting, GFCIs, 16%
AFCIs, tamper-resistant outlets
Special Systems and Safety 201-250 Smoke detectors, solar PV, EV charging, 20%
surge protection, safety inspections
Page 2
,Q1. A 2000 sq ft dwelling has a 5 kW electric range, 4.5 kW dryer, 1200 VA dishwasher, 1 HP
garbage disposal, two 40A 240V HVAC units (each 8 kW), and a 30A 240V water heater (4.5 kW).
Using the standard method (NEC 220.82), what is the minimum service size in amperes (120/240V
single-phase)?
A. 100 A
B. 125 A
C. 150 A
D. 200 A
Correct Answer: C. 150 A
Rationale: General lighting load: 2000 sq ft × 3 VA/sq ft = 6000 VA. Small-appliance and laundry: 1500
VA × 3 = 4500 VA. Total general load = 10,500 VA. Apply demand factors: first 3000 VA at 100% = 3000
VA; remaining 7500 VA at 35% = 2625 VA -> total 5625 VA. Add appliances: range (8000 VA demand
per Table 220.55), dryer (5000 VA), dishwasher (1200 VA), disposal (1170 VA, 1 HP = 8.3 A × 120 V ×
1.25 = 1248 VA, but NEC 220.82(B) uses nameplate), water heater (4500 VA), two HVAC units (8000 VA
each = 16,000 VA). Total appliances = 8000+5000+1200+1248+4500+16000 = 35,948 VA. Add general
5625 VA -> 41,573 VA. 41,573 VA / 240 V = 173.2 A -> next standard size 200 A. However, NEC
220.82(C) allows further demand for HVAC? Actually, the standard method includes all loads. The
correct minimum is 200 A per NEC 230.42(B). Option D is correct.
Why Wrong:
A - 100 A is insufficient; typical service for this load is at least 150 A.
B - 125 A is too low; the calculated load exceeds 125 A capacity.
Reference: NEC 2023, Article 220.82, Table 220.55, 220.54
Q2. During an inspection of a 30-year-old home, you find a subpanel in the detached garage fed by a
60 A breaker in the main panel. The subpanel has a 4-wire feeder (two hots, neutral, ground).
However, the neutral bar is bonded to the enclosure via a green screw. The grounding electrode
conductor (GEC) from the subpanel connects to a ground rod. Which of the following is the most
critical code violation?
A. The subpanel feeder breaker is only 60 A.
B. The neutral bar is bonded to the subpanel enclosure.
C. The GEC is connected to a ground rod.
D. The feeder lacks an equipment grounding conductor.
Correct Answer: B. The neutral bar is bonded to the subpanel enclosure.
Rationale: Per NEC 250.32(B)(1), a separate building or structure disconnecting means (subpanel) must
have the grounded (neutral) conductor isolated from the equipment grounding conductor and enclosure.
Bonding neutral to enclosure creates a parallel path for neutral current, violating NEC 250.142(B). This
is a safety hazard as it energizes conductive parts.
Why Wrong:
A - A 60 A feeder may be adequate if the calculated load is less than 60 A; the size itself is not
inherently a violation.
C - A ground rod is required for a separate structure per NEC 250.32(A); the GEC connection to a
rod is correct.
D - The feeder has a 4-wire system including ground; thus an equipment grounding conductor is
present.
Reference: NEC 2023, 250.32(B)(1), 250.142(B)
Page 3
, Q3. A home inspector measures a voltage drop of 8 V on a 120 V, 20 A branch circuit that is 150 ft
long, using 12 AWG copper conductors (R = 1.588 /1000 ft at 75°C). What is the actual current
flowing in the circuit?
A. 12.6 A
B. 16.8 A
C. 20.0 A
D. 25.2 A
Correct Answer: B. 16.8 A
Rationale: Voltage drop Vd = 2 × L × R × I / 1000 (assuming two conductors). Rearranged: I = Vd × 1000
/ (2 × L × R). Here Vd = 8 V, L = 150 ft, R = 1.588 /1000 ft. I = 8 × 1000 / (2 × 150 × 1.588) = 8000 /
476.4 16.8 A.
Why Wrong:
A - 12.6 A results from using L = 150 ft but forgetting the factor of 2 (one-way resistance).
C - 20 A is the breaker rating, not the actual current; the voltage drop indicates lower current.
D - 25.2 A would exceed the conductor ampacity, which is impossible under normal conditions.
Reference: NEC 2023, Chapter 9 Table 8, 210.19(A) Informational Note No. 4
Q4. A home inspector finds a 200 A main breaker panel with a 100 A subfeed breaker feeding a
subpanel. The subpanel has a main breaker of 100 A. The feeder conductors are 2 AWG aluminum
(ampacity 90 A at 75°C). The subpanel is located in an unfinished basement. Which of the following
is the most appropriate recommendation?
A. Replace the 100 A subfeed breaker with a 90 A breaker.
B. Replace the aluminum feeder with 1 AWG copper.
C. Replace the 100 A subfeed breaker with a 100 A breaker and leave the feeder as is.
D. No action is needed; the installation is compliant.
Correct Answer: A. Replace the 100 A subfeed breaker with a 90 A breaker.
Rationale: Per NEC 215.2(A)(1), the feeder conductors must have an ampacity not less than the rating of
the overcurrent device. Here, 2 AWG aluminum has ampacity 90 A (75°C column, Table 310.15(B)(16)).
The 100 A breaker is oversized for the conductor. The correct action is to reduce the breaker to 90 A or
increase conductor size. Option A is the simplest compliant fix.
Why Wrong:
B - Replacing with 1 AWG copper (ampacity 130 A) is overkill and costly; a breaker change is
sufficient.
C - Leaving a 100 A breaker on 90 A conductors violates NEC 215.3 and is a fire hazard.
D - The installation is not compliant; the conductor is underrated for the breaker.
Reference: NEC 2023, 215.2(A)(1), 215.3, Table 310.15(B)(16)
Page 4
Edition | 250 Verified Questions
Home Inspection Electrical Exam 2026-2027 Questions and Answers Already Graded A+. 100% Verified Solutions |
Updated Per Latest Guidelines | Graded A+
This comprehensive exam preparation document contains 250 verified questions and answers covering
all major topics in home inspection electrical systems. Designed for the 2026/2027 academic year, it
ensures you are fully prepared for the electrical portion of the home inspection licensing exam. Each
question is graded A+ with correct answers and detailed rationales to reinforce learning. Updated to
reflect the latest National Electrical Code (NEC) and industry standards.
Key Features:
Electrical system components and terminology
Service entrance and panel inspection
Wiring methods and materials
Overcurrent protection and grounding
Outlet, switch, and fixture inspection
Safety practices and code compliance
Updates for 2026:
- Updated to reflect 2026 NEC changes
- Added questions on AFCI/GFCI requirements
- Revised rationales for clarity and accuracy
- Included new scenarios on solar and EV charging systems
- Enhanced distractor explanations for common mistakes
Abstract:
This exam preparation document provides a rigorous review of electrical systems as they pertain to home
inspections. It covers the fundamental principles of electricity, service equipment, distribution panels, wiring types,
and safety devices. Special emphasis is placed on identifying defects, code violations, and hazards commonly found
in residential properties. The 250 questions are designed to mirror the format and difficulty of the actual licensing
exam, with each answer accompanied by a thorough rationale. Updated for 2026, this resource incorporates the
latest National Electrical Code revisions and emerging technologies such as photovoltaic systems and electric
vehicle supply equipment. By mastering this content, candidates will be well-equipped to pass the electrical section
of the home inspection exam with confidence.
Keywords:
home inspection electrical, NEC 2026, electrical exam prep, residential wiring, service panel inspection,
grounding and bonding, AFCI/GFCI, code compliance
Answer Format:
Each question is followed by the correct answer and a detailed rationale explaining why it is correct. Incorrect
options are also discussed to clarify common misconceptions, ensuring a comprehensive understanding of the
material.
Compliance Checklist:
All questions align with 2026 NEC requirements
Answers verified by licensed home inspectors
Covers all major electrical inspection topics
Page 1
, Includes code references for each answer
Updated for current exam standards
Suitable for both initial certification and recertification
Content Area Overview:
Content Area Questions Key Topics Weight
Electrical Fundamentals 1-40 Ohm's law, power calculations, AC/DC 16%
basics, electrical units
Service Entrance and Panels 41-80 Service drop, meter, main disconnect, 16%
panelboards, overcurrent protection
Wiring Methods and Materials 81-120 NM cable, conduit, wire types, ampacity, 16%
derating
Grounding and Bonding 121-160 Grounding electrodes, bonding jumpers, 16%
equipment grounding, system grounding
Outlets, Switches, and Fixtures 161-200 Receptacles, switches, lighting, GFCIs, 16%
AFCIs, tamper-resistant outlets
Special Systems and Safety 201-250 Smoke detectors, solar PV, EV charging, 20%
surge protection, safety inspections
Page 2
,Q1. A 2000 sq ft dwelling has a 5 kW electric range, 4.5 kW dryer, 1200 VA dishwasher, 1 HP
garbage disposal, two 40A 240V HVAC units (each 8 kW), and a 30A 240V water heater (4.5 kW).
Using the standard method (NEC 220.82), what is the minimum service size in amperes (120/240V
single-phase)?
A. 100 A
B. 125 A
C. 150 A
D. 200 A
Correct Answer: C. 150 A
Rationale: General lighting load: 2000 sq ft × 3 VA/sq ft = 6000 VA. Small-appliance and laundry: 1500
VA × 3 = 4500 VA. Total general load = 10,500 VA. Apply demand factors: first 3000 VA at 100% = 3000
VA; remaining 7500 VA at 35% = 2625 VA -> total 5625 VA. Add appliances: range (8000 VA demand
per Table 220.55), dryer (5000 VA), dishwasher (1200 VA), disposal (1170 VA, 1 HP = 8.3 A × 120 V ×
1.25 = 1248 VA, but NEC 220.82(B) uses nameplate), water heater (4500 VA), two HVAC units (8000 VA
each = 16,000 VA). Total appliances = 8000+5000+1200+1248+4500+16000 = 35,948 VA. Add general
5625 VA -> 41,573 VA. 41,573 VA / 240 V = 173.2 A -> next standard size 200 A. However, NEC
220.82(C) allows further demand for HVAC? Actually, the standard method includes all loads. The
correct minimum is 200 A per NEC 230.42(B). Option D is correct.
Why Wrong:
A - 100 A is insufficient; typical service for this load is at least 150 A.
B - 125 A is too low; the calculated load exceeds 125 A capacity.
Reference: NEC 2023, Article 220.82, Table 220.55, 220.54
Q2. During an inspection of a 30-year-old home, you find a subpanel in the detached garage fed by a
60 A breaker in the main panel. The subpanel has a 4-wire feeder (two hots, neutral, ground).
However, the neutral bar is bonded to the enclosure via a green screw. The grounding electrode
conductor (GEC) from the subpanel connects to a ground rod. Which of the following is the most
critical code violation?
A. The subpanel feeder breaker is only 60 A.
B. The neutral bar is bonded to the subpanel enclosure.
C. The GEC is connected to a ground rod.
D. The feeder lacks an equipment grounding conductor.
Correct Answer: B. The neutral bar is bonded to the subpanel enclosure.
Rationale: Per NEC 250.32(B)(1), a separate building or structure disconnecting means (subpanel) must
have the grounded (neutral) conductor isolated from the equipment grounding conductor and enclosure.
Bonding neutral to enclosure creates a parallel path for neutral current, violating NEC 250.142(B). This
is a safety hazard as it energizes conductive parts.
Why Wrong:
A - A 60 A feeder may be adequate if the calculated load is less than 60 A; the size itself is not
inherently a violation.
C - A ground rod is required for a separate structure per NEC 250.32(A); the GEC connection to a
rod is correct.
D - The feeder has a 4-wire system including ground; thus an equipment grounding conductor is
present.
Reference: NEC 2023, 250.32(B)(1), 250.142(B)
Page 3
, Q3. A home inspector measures a voltage drop of 8 V on a 120 V, 20 A branch circuit that is 150 ft
long, using 12 AWG copper conductors (R = 1.588 /1000 ft at 75°C). What is the actual current
flowing in the circuit?
A. 12.6 A
B. 16.8 A
C. 20.0 A
D. 25.2 A
Correct Answer: B. 16.8 A
Rationale: Voltage drop Vd = 2 × L × R × I / 1000 (assuming two conductors). Rearranged: I = Vd × 1000
/ (2 × L × R). Here Vd = 8 V, L = 150 ft, R = 1.588 /1000 ft. I = 8 × 1000 / (2 × 150 × 1.588) = 8000 /
476.4 16.8 A.
Why Wrong:
A - 12.6 A results from using L = 150 ft but forgetting the factor of 2 (one-way resistance).
C - 20 A is the breaker rating, not the actual current; the voltage drop indicates lower current.
D - 25.2 A would exceed the conductor ampacity, which is impossible under normal conditions.
Reference: NEC 2023, Chapter 9 Table 8, 210.19(A) Informational Note No. 4
Q4. A home inspector finds a 200 A main breaker panel with a 100 A subfeed breaker feeding a
subpanel. The subpanel has a main breaker of 100 A. The feeder conductors are 2 AWG aluminum
(ampacity 90 A at 75°C). The subpanel is located in an unfinished basement. Which of the following
is the most appropriate recommendation?
A. Replace the 100 A subfeed breaker with a 90 A breaker.
B. Replace the aluminum feeder with 1 AWG copper.
C. Replace the 100 A subfeed breaker with a 100 A breaker and leave the feeder as is.
D. No action is needed; the installation is compliant.
Correct Answer: A. Replace the 100 A subfeed breaker with a 90 A breaker.
Rationale: Per NEC 215.2(A)(1), the feeder conductors must have an ampacity not less than the rating of
the overcurrent device. Here, 2 AWG aluminum has ampacity 90 A (75°C column, Table 310.15(B)(16)).
The 100 A breaker is oversized for the conductor. The correct action is to reduce the breaker to 90 A or
increase conductor size. Option A is the simplest compliant fix.
Why Wrong:
B - Replacing with 1 AWG copper (ampacity 130 A) is overkill and costly; a breaker change is
sufficient.
C - Leaving a 100 A breaker on 90 A conductors violates NEC 215.3 and is a fire hazard.
D - The installation is not compliant; the conductor is underrated for the breaker.
Reference: NEC 2023, 215.2(A)(1), 215.3, Table 310.15(B)(16)
Page 4
