CHI Electrical Systems Inspection 2 — Questions and Answers
Question 1: What is the minimum clearance required between the top of a residential electrical panel and the ceiling?
- 3 feet
- 6 feet (Correct answer)
- 6.5 feet
- 4 feet
Correct answer: 6 feet
NEC requires a minimum of 6 feet of headroom above electrical panels to allow safe working space.
Question 2: Which condition is indicated when a home inspector finds aluminum wiring connected directly to a standard duplex receptacle rated for copper only?
- Acceptable if the wire is 10 AWG or larger
- A potential fire hazard due to galvanic incompatibility (Correct answer)
- Normal practice in homes built before 1980
- Safe as long as the receptacle is GFCI protected
Correct answer: A potential fire hazard due to galvanic incompatibility
Aluminum wiring connected to copper-only devices creates a galvanic reaction that can cause overheating and fire hazard.
Question 3: A home inspector observes double-tapping on a circuit breaker. What does this mean?
- Two wires are connected to a single breaker terminal not rated for it (Correct answer)
- The breaker has been tested twice during inspection
- Two breakers share the same bus bar slot
- The panel has a tandem breaker installed
Correct answer: Two wires are connected to a single breaker terminal not rated for it
Double-tapping occurs when two conductors are connected to a breaker terminal designed for only one, creating a potential loose connection and fire hazard.
Question 4: What does a home inspector look for when inspecting knob-and-tube wiring?
- Whether it has been properly grounded
- Signs of insulation contact, splices, or modifications (Correct answer)
- Confirmation that it is connected to a 200-amp panel
- Whether AFCI breakers protect all circuits
Correct answer: Signs of insulation contact, splices, or modifications
Knob-and-tube wiring must be inspected for improper modifications, contact with insulation (fire hazard), and unauthorized splices.
Question 5: Which of the following is a reportable deficiency when inspecting a sub-panel in a detached garage?
- The panel is fed by a 4-wire feeder cable
- The neutral and ground conductors are bonded together at the sub-panel (Correct answer)
- The panel is surface-mounted on the wall
- A 20-amp breaker protects the lighting circuit
Correct answer: The neutral and ground conductors are bonded together at the sub-panel
In a sub-panel, the neutral and ground must be kept separate; bonding them together creates a shock hazard on the grounding path.
Question 6: A home inspector finds an ungrounded three-prong receptacle in a 1955 home. What is the safest acceptable remedy according to the NEC?
- Replace with a two-prong receptacle and label it
- Install a GFCI receptacle and label it 'No Equipment Ground' (Correct answer)
- Run a new grounded circuit from the panel
- Add a ground rod at the receptacle location
Correct answer: Install a GFCI receptacle and label it 'No Equipment Ground'
The NEC permits replacing ungrounded receptacles with GFCI devices labeled 'No Equipment Ground' as a code-compliant alternative to rewiring.
Question 7: When inspecting a service entrance, a home inspector notes the service drop conductors are less than 10 feet above a driveway. What is the concern?
- The conductors may interfere with radio signals
- A vehicle could contact the conductors, creating an electrocution hazard (Correct answer)
- The conductors will corrode faster at lower heights
- The utility company will not connect service at this height
Correct answer: A vehicle could contact the conductors, creating an electrocution hazard
The NEC requires service conductors to be at least 10 feet above driveways to prevent vehicles from contacting energized wires.
CHI Electrical Systems Inspection 2
What is the minimum clearance required between the top of a residential electrical panel and the ceiling?