InterNACHI Electrical Systems & Safety 3 — Questions and Answers
Question 1: According to NEC, GFCI protection is required in which of the following locations?
- Interior hallways
- Bedrooms
- Bathroom receptacles (Correct answer)
- Living room receptacles
Correct answer: Bathroom receptacles
NEC mandates GFCI protection for all bathroom receptacles due to the proximity of water sources.
Question 2: What is the purpose of a bonding jumper in an electrical system?
- To increase the ampacity of the main service
- To connect grounded metal parts to ensure a low-impedance fault path (Correct answer)
- To separate the neutral and ground conductors at sub-panels
- To protect against lightning strikes
Correct answer: To connect grounded metal parts to ensure a low-impedance fault path
A bonding jumper connects all metallic components of the electrical system to ensure a reliable path for fault current to flow back to the source.
Question 3: What wire gauge is required for a 20-amp branch circuit using copper conductors?
- 14 AWG
- 12 AWG (Correct answer)
- 10 AWG
- 8 AWG
Correct answer: 12 AWG
A 20-amp circuit requires 12 AWG copper conductors, as 14 AWG is only rated for 15-amp circuits.
Question 4: A home inspector finds a 15-amp breaker protecting a circuit with 12 AWG wire. This is:
- A safety violation requiring immediate correction
- Acceptable — the wire exceeds the breaker's ampacity rating (Correct answer)
- A concern only if the circuit serves a bathroom
- Not permitted under any code
Correct answer: Acceptable — the wire exceeds the breaker's ampacity rating
Using 12 AWG wire on a 15-amp breaker is acceptable because the wire can handle more current than the breaker will allow.
Question 5: Which of the following describes a 'floating neutral' condition at a sub-panel?
- The neutral bus is not connected to the ground bus, as required
- The neutral wire is connected to the ground bus, creating a fault path (Correct answer)
- The neutral conductor has higher-than-normal resistance
- The neutral is energized due to a utility issue
Correct answer: The neutral wire is connected to the ground bus, creating a fault path
At a sub-panel, a floating neutral means the neutral bus is incorrectly bonded to the ground bus, which should only occur at the main panel.
Question 6: What is the maximum height at which a wall switch controlling a light may be installed per accessibility standards?
- 36 inches
- 44 inches
- 48 inches (Correct answer)
- 54 inches
Correct answer: 48 inches
ADA and accessibility guidelines recommend wall switches be installed no higher than 48 inches above the finished floor.
Question 7: When inspecting a service entrance, what does the inspector look for at the weatherhead?
- Proper fusing of all three service conductors
- Adequate drip loop to prevent water from entering the conduit (Correct answer)
- A minimum of four conductors entering the home
- A disconnect within 3 feet of the meter
Correct answer: Adequate drip loop to prevent water from entering the conduit
A drip loop is essential at the weatherhead to ensure rainwater drips off the conductors before reaching the entry point rather than running into the conduit.
InterNACHI Electrical Systems & Safety 3
According to NEC, GFCI protection is required in which of the following locations?