Licensed Electrical Contractor Safety and OSHA Regulations 3 — Questions and Answers
Question 1: Under NFPA 70E, what is the 'restricted approach boundary' for shock protection?
- The distance at which an arc flash can cause a curable burn
- The closest distance an unqualified person may approach energized parts
- The distance within which a shock hazard exists requiring special precautions (Correct answer)
- The boundary beyond which no PPE is required
Correct answer: The distance within which a shock hazard exists requiring special precautions
The restricted approach boundary is the distance from an exposed energized conductor within which a shock hazard exists, requiring insulating PPE and other precautions.
Question 2: Which of the following conditions would require an Occupational Safety and Health Administration (OSHA) Form 300 Log entry for an electrical incident?
- A worker receives a minor electrical shock with no medical treatment beyond first aid
- A worker misses one day of work after being shocked (Correct answer)
- A worker is shocked but returns to full duty immediately
- A worker receives first aid treatment only for a burn
Correct answer: A worker misses one day of work after being shocked
OSHA 300 Log recording is required when an injury results in days away from work, restricted work, job transfer, medical treatment beyond first aid, or loss of consciousness.
Question 3: An electrical contractor is working in a permit-required confined space that contains atmospheric hazards. Which OSHA standard applies?
- 29 CFR 1910.147
- 29 CFR 1910.146 (Correct answer)
- 29 CFR 1926.405
- 29 CFR 1910.303
Correct answer: 29 CFR 1910.146
29 CFR 1910.146 covers permit-required confined spaces in general industry, establishing entry procedures, atmospheric testing, and attendant requirements.
Question 4: What minimum AFCI protection does the 2023 NEC require for branch circuits supplying all 15A and 20A, 120V outlets in a bedroom?
- Ground-fault circuit interrupter (GFCI) only
- Both AFCI and GFCI protection on the same circuit
- Arc-fault circuit interrupter (AFCI) protection (Correct answer)
- No special protection is required
Correct answer: Arc-fault circuit interrupter (AFCI) protection
The NEC requires AFCI protection for all 15A and 20A, 120V branch circuits supplying outlets in bedrooms to protect against arc-fault ignition of fires.
Question 5: Under OSHA 29 CFR 1926.405(j), extension cords used on construction sites must be which type?
- Type S, SO, ST, STO, SJ, SJO, SJT, or SJTO listed for hard or extra-hard usage (Correct answer)
- Any cord listed by UL for indoor use
- Any 14 AWG or larger cord
- Type NM cable is acceptable as an extension cord
Correct answer: Type S, SO, ST, STO, SJ, SJO, SJT, or SJTO listed for hard or extra-hard usage
OSHA requires construction extension cords to be of the hard or extra-hard usage types (S, SO, ST, STO, SJ, SJO, SJT, SJTO) to withstand job-site abuse.
Question 6: What is the purpose of a 'job hazard analysis' (JHA) before starting electrical work?
- To satisfy OSHA recordkeeping requirements after an incident
- To systematically identify hazards and controls before work begins (Correct answer)
- To determine insurance liability for the project
- To document completed safety training for workers
Correct answer: To systematically identify hazards and controls before work begins
A JHA (also called job safety analysis) proactively identifies hazards associated with each task step and establishes controls before work begins, reducing injury risk.
Question 7: When using a voltage detector (tick tracer) to verify a circuit is de-energized, what additional verification step is required by NFPA 70E?
- Test the detector on a known energized source before and after testing the circuit (Correct answer)
- Test the circuit at three separate points
- Have a second qualified person independently test the circuit
- Document the test results on the lockout/tagout permit
Correct answer: Test the detector on a known energized source before and after testing the circuit
NFPA 70E requires voltage-detecting equipment to be tested on a known energized source immediately before and after testing the circuit to verify the detector is functioning properly.
Licensed Electrical Contractor Safety and OSHA Regulations 3
Under NFPA 70E, what is the 'restricted approach boundary' for shock protection?