Special Occupancies and Equipment Flashcards

Under NEC Article 680, a storable swimming pool uses flexible cords for underwater luminaires. What is the maximum length permitted for such a cord?

Answer: 3 feet

NEC 680.23(B)(3) limits flexible cords on storable pool underwater luminaires to a maximum of 3 feet to minimize shock exposure.

Per NEC Article 702, a legally required standby system must restore power to loads within what maximum time after normal supply failure?

Answer: 60 seconds

NEC 702.4 requires legally required standby systems to supply power within 60 seconds of normal supply failure.

In a Class III location involving ignitable fibers, which statement best describes the hazard classification?

Answer: Class III locations contain ignitable fibers or flyings not likely to be suspended

NEC 500.5(D) defines Class III locations as those where ignitable fibers or flyings are handled, manufactured, or used, but are not likely to be in suspension in quantities to produce ignitable mixtures.

For an information technology equipment room (ITE room) covered by NEC Article 645, which condition must be met to allow alternate wiring methods such as flexible cords under raised floors?

Answer: The room must have only IT equipment and the supply circuit disconnect must shut down all power in the room upon activation

NEC 645.4 permits alternate wiring methods in ITE rooms only when the room contains only IT equipment and a single disconnect shuts off all power to the room's IT equipment when activated.

Under NEC Article 504, intrinsically safe systems in hazardous locations use energy-limiting barriers. What must separate intrinsically safe conductors from non-intrinsically safe conductors in the same raceway?

Answer: They cannot share any raceway regardless of separation

NEC 504.30(A) prohibits intrinsically safe conductors from occupying the same raceway, cable tray, or cable as non-intrinsically safe conductors.

A marina shore power receptacle per NEC 553.4 must be mounted at a height that keeps it above the deck level. What is the purpose of this requirement?

Answer: To prevent the receptacle from being submerged during high water or wave action

Mounting the receptacle above deck prevents submersion from wave action or tidal variation, which would create a severe shock or electrocution hazard in the water.

Under NEC Article 590, temporary wiring for construction sites must be removed within how many days after the completion of construction?

Answer: It must be removed immediately upon completion

NEC 590.3(B) requires temporary wiring for construction to be removed immediately upon completion of construction or the purpose for which it was installed.