ICC Electrical Systems and Safety 3 — Questions and Answers
Question 1: What is the minimum wire gauge required for a 20-ampere branch circuit in a residential installation?
- 14 AWG
- 12 AWG (Correct answer)
- 10 AWG
- 8 AWG
Correct answer: 12 AWG
12 AWG copper wire is the minimum size required for 20-ampere branch circuits to prevent overheating.
Question 2: In Illinois, electrical inspections for new residential construction are performed by:
- The homeowner
- A licensed ICC contractor only
- The local authority having jurisdiction (AHJ) (Correct answer)
- The utility company
Correct answer: The local authority having jurisdiction (AHJ)
The Authority Having Jurisdiction (AHJ), typically the local building department, performs mandatory electrical inspections.
Question 3: What is the maximum length of a flexible cord used as a substitute for permanent wiring under Illinois electrical code?
- There is no limit
- Flexible cords may never substitute for permanent wiring (Correct answer)
- 6 feet
- 10 feet
Correct answer: Flexible cords may never substitute for permanent wiring
The NEC, adopted in Illinois, prohibits the use of flexible cords as a substitute for permanent fixed wiring.
Question 4: Which of the following is a lockout/tagout (LOTO) requirement when performing electrical maintenance in Illinois?
- Work quickly to minimize downtime
- Isolate and de-energize all energy sources before beginning work (Correct answer)
- Wear rubber gloves as the only precaution
- Notify the utility company by phone
Correct answer: Isolate and de-energize all energy sources before beginning work
Lockout/Tagout procedures require that all energy sources be isolated and locked out before any maintenance work begins.
Question 5: What is the required height for service entrance conductors over a public sidewalk in Illinois?
- 8 feet
- 10 feet (Correct answer)
- 12 feet
- 15 feet
Correct answer: 10 feet
Service entrance conductors must maintain a minimum height of 10 feet over pedestrian areas such as public sidewalks.
Question 6: Which piece of personal protective equipment (PPE) is essential when working on or near energized electrical panels?
- Hard hat only
- Arc flash-rated face shield and flame-resistant clothing (Correct answer)
- Standard safety glasses only
- Latex gloves and a dust mask
Correct answer: Arc flash-rated face shield and flame-resistant clothing
Arc flash-rated PPE including a face shield and flame-resistant clothing protect workers from the extreme heat and pressure of an arc flash event.
ICC Electrical Systems and Safety 3
What is the minimum wire gauge required for a 20-ampere branch circuit in a residential installation?