AEP Code Compliance & Standards 2 — Questions and Answers
Question 1: Under NFPA 70E, what is the minimum approach boundary within which an arc flash hazard exists and PPE is required?
- Limited approach boundary
- Restricted approach boundary
- Arc flash boundary (Correct answer)
- Prohibited approach boundary
Correct answer: Arc flash boundary
The arc flash boundary is the distance at which a worker could receive a second-degree burn from an arc flash event and requires appropriate PPE.
Question 2: Which ANSI/IEEE standard covers the design and performance of power distribution switchgear rated above 1000V?
- ANSI C37.20.1
- ANSI C37.20.2 (Correct answer)
- ANSI C37.20.3
- ANSI C37.20.4
Correct answer: ANSI C37.20.2
ANSI C37.20.2 covers metal-clad switchgear for voltages above 1000V, defining construction and performance requirements.
Question 3: According to OSHA 29 CFR 1910.269, what is required before an employee works on energized electrical equipment?
- Written job plan approved by a supervisor
- An energized electrical work permit (Correct answer)
- A lockout/tagout authorization form
- A PPE inspection checklist
Correct answer: An energized electrical work permit
OSHA 1910.269 and NFPA 70E both require an energized electrical work permit when work must be performed on or near energized conductors.
Question 4: What does the term 'interrupting rating' refer to in the context of electrical overcurrent protective devices?
- The maximum current the device can carry continuously
- The minimum current at which the device will trip
- The maximum fault current the device can safely interrupt (Correct answer)
- The time delay before the device opens under overload
Correct answer: The maximum fault current the device can safely interrupt
Interrupting rating (short-circuit current rating) is the maximum fault current a protective device can interrupt without damage or hazard.
Question 5: Under NEC Article 250, what is the primary purpose of equipment grounding conductors (EGC)?
- To carry normal load current back to the source
- To provide a low-impedance path for fault current to operate overcurrent protection (Correct answer)
- To prevent static charge buildup on metal enclosures
- To equalize voltage between different circuits
Correct answer: To provide a low-impedance path for fault current to operate overcurrent protection
Equipment grounding conductors provide a low-impedance fault current path that enables overcurrent devices to operate and clear the fault quickly.
Question 6: Which regulatory body publishes the NESC (National Electrical Safety Code) used by utilities like AEP for transmission and distribution standards?
- OSHA
- NFPA
- IEEE (Correct answer)
- ANSI
Correct answer: IEEE
The NESC is published by IEEE (Institute of Electrical and Electronics Engineers) and sets safety standards for electric supply and communication lines.
Question 7: What NESC requirement applies to minimum vertical clearance of overhead distribution conductors over roadways accessible to trucks?
- 15.5 feet
- 18 feet (Correct answer)
- 20 feet
- 24 feet
Correct answer: 18 feet
The NESC requires a minimum vertical clearance of 18 feet for conductors over roadways accessible to trucks and other large vehicles.
AEP Code Compliance & Standards 2
Under NFPA 70E, what is the minimum approach boundary within which an arc flash hazard exists and PPE is required?