PC Safety Practices & Risk Management 3

Question 1

Which personal protective equipment (PPE) category under NFPA 70E requires an arc rating of at least 40 cal/cm²?

Accepted Answer

Category 4

Answer

NFPA 70E PPE Category 4 requires arc-rated clothing and equipment with a minimum arc rating of 40 cal/cm².

Question 2

What is the purpose of an equipotential bonding jumper in electrical safety?

Accepted Answer

To eliminate voltage differences between conductive parts that could cause shock

Answer

Equipotential bonding connects conductive parts so no voltage difference exists between them, preventing shock hazards.

Question 3

Under OSHA 29 CFR 1926.416, unqualified workers must stay at least how far from overhead power lines under 50 kV?

Accepted Answer

10 feet

Answer

OSHA requires unqualified workers (and equipment) to maintain at least 10 feet from overhead power lines rated up to 50 kV.

Question 4

A Ground Fault Circuit Interrupter (GFCI) protects workers by:

Accepted Answer

Tripping when it detects a current difference between hot and neutral conductors of as little as 5 mA

Answer

A GFCI monitors current imbalance between hot and neutral; a leakage as small as 4–6 mA triggers a trip in about 1/40th of a second.

Question 5

Which of the following best defines 'electrically safe work condition'?

Accepted Answer

All energy sources are locked out, tested de-energized, and grounded as required

Answer

An electrically safe work condition requires isolation, lockout, verification of de-energization, and grounding per NFPA 70E Article 120.

(PC) Professional Electrical Contractor Practice Test