ESC ESC Arc Flash & PPE Selection 2 — Questions and Answers
Question 1: What voltage rating applies to Class 0 rubber insulating gloves?
- 500 volts AC
- 1,000 volts AC (Correct answer)
- 7,500 volts AC
- 17,000 volts AC
Correct answer: 1,000 volts AC
Class 0 rubber insulating gloves are rated for a maximum use voltage of 1,000 volts AC, proof-tested to 5,000V AC.
Question 2: What is the limited approach boundary?
- The distance inside which only qualified persons may approach exposed energized conductors (Correct answer)
- The distance at which arc flash energy equals 1.2 cal/cm²
- The outer perimeter of any arc flash hazard area
- The maximum reach distance for insulated tools
Correct answer: The distance inside which only qualified persons may approach exposed energized conductors
The limited approach boundary is the distance from an exposed energized conductor within which only qualified electrical workers are permitted to work.
Question 3: What information must an arc flash warning label on electrical equipment include at minimum per NFPA 70E 130.5(H)?
- Only the voltage rating
- The available incident energy or required PPE category, and the working distance used (Correct answer)
- Only the required PPE category
- The name of the engineer who performed the analysis
Correct answer: The available incident energy or required PPE category, and the working distance used
NFPA 70E 130.5(H) requires arc flash labels to include at minimum the incident energy or PPE category and the working distance used in the analysis.
Question 4: The prohibited approach boundary is the distance within which:
- Face shields must be worn
- Working on energized conductors is considered the same risk as direct contact (Correct answer)
- The outer electrical safety zone begins
- Only insulated tools may be used
Correct answer: Working on energized conductors is considered the same risk as direct contact
Within the prohibited approach boundary, the risk of electrical shock is considered equivalent to direct contact with the exposed energized part.
Question 5: What must always be worn over rubber insulating gloves during energized electrical work?
- Chemical-resistant gloves
- Anti-vibration gloves
- Leather protector gloves (Correct answer)
- Cut-resistant gloves
Correct answer: Leather protector gloves
Leather protector gloves must be worn over rubber insulating gloves to protect the rubber from puncture and mechanical damage while maintaining electrical protection.
Question 6: What does ATPV stand for in arc-rated PPE?
- Arc Thermal Performance Value — the incident energy at which there is a 50% probability of a second-degree burn (Correct answer)
- Arc Testing Protocol Voltage
- Average Thermal Protection Value
- Arc-rated Thermal Protective Vest
Correct answer: Arc Thermal Performance Value — the incident energy at which there is a 50% probability of a second-degree burn
ATPV (Arc Thermal Performance Value) is the incident energy level at which there is a 50% probability of causing the onset of a second-degree burn through the protective fabric.
ESC ESC Arc Flash & PPE Selection 2
What voltage rating applies to Class 0 rubber insulating gloves?