IEC Special Occupancies and Equipment 5 — Questions and Answers
Question 1: In a health care facility, the essential electrical system must restore power to life safety circuits within:
- 5 seconds
- 10 seconds (Correct answer)
- 30 seconds
- 60 seconds
Correct answer: 10 seconds
NEC 517.31 requires the life safety branch of the essential electrical system to restore power within 10 seconds of a normal power failure.
Question 2: A spray booth used for applying flammable finishes is classified as which type of hazardous location?
- Class I, Division 1 (Correct answer)
- Class I, Division 2
- Class II, Division 1
- Class III, Division 2
Correct answer: Class I, Division 1
Spray booths using flammable liquids or coatings are classified as Class I, Division 1 because flammable vapors are present during normal operations.
Question 3: Equipotential bonding around a swimming pool is required to bond metal parts within how many inches of the inside wall of the pool?
- 3 inches
- 5 inches (Correct answer)
- 6 inches
- 12 inches
Correct answer: 5 inches
NEC 680.26 requires all metal parts within 5 feet of the inside walls of a pool to be bonded together to eliminate voltage gradients.
Question 4: In a recreational vehicle park, each RV site must be provided with at minimum which electrical supply?
- 20-ampere, 120-volt only
- 30-ampere, 120-volt only
- 20- and 30-ampere, 120-volt (Correct answer)
- 50-ampere, 120/240-volt
Correct answer: 20- and 30-ampere, 120-volt
NEC 551.71 requires each RV site to have at least one 20-ampere and one 30-ampere, 120-volt receptacle to accommodate different RV configurations.
Question 5: What must be installed at the point where flexible conduit connects to a motor in a Class I, Division 1 location?
- A watertight fitting
- An explosion-proof flexible connector listed for the location (Correct answer)
- A standard LB fitting
- A weatherproof seal-off
Correct answer: An explosion-proof flexible connector listed for the location
Flexible connections to motors in Class I, Division 1 locations must use explosion-proof flexible fittings listed for use in those hazardous locations.
Question 6: For a patient care area in a hospital, the branch circuit must supply no more than how many patient bed locations?
- 1
- 2 (Correct answer)
- 4
- 6
Correct answer: 2
NEC 517.18 limits each branch circuit in general patient care areas to serving no more than two patient bed locations.
Question 7: In an aircraft hangar, the area within 5 feet of any aircraft engine fuel tank is classified as:
- Unclassified
- Class I, Division 2
- Class I, Division 1 (Correct answer)
- Class II, Division 1
Correct answer: Class I, Division 1
NEC 513.3 classifies the area within 5 feet of aircraft fuel tanks as Class I, Division 1 due to the likelihood of flammable vapor release during fueling operations.
IEC Special Occupancies and Equipment 5
In a health care facility, the essential electrical system must restore power to life safety circuits within: