When installing a transformer (such as a 75kVA unit), the disconnecting means for this piece of equipment shall be _________, and the location of the disconnecting means shall be ______ marked on the transformer.
Q. Exposed non-current-carrying metal parts of small wind electric systems, such as towers, turbine nacelles, other equipment, and conductor enclosures shall be connected to an equipment grounding conductor [in accordance with 250.134 or 250.136(A)] at what voltage level?
A. All voltage levels
B. 50V or more
C. 600V or more
D. 1,000V or more
Fill in the blanks with the appropriate answers.
Q. Where a building exceeds _______ stories, or ____ ft or more in height, overhead lines shall be arranged, where practicable to, so that a clear space (or zone) at least 6 ft wide will be left either adjacent to the buildings, or beginning not over 8 ft from them to facilitate the raising of ladders when necessary for fire fighting. Note: This relates to conductors operating at 600V or less nominal.
Where in the NEC does it state, "completed wiring installations shall be free from short circuits, ground faults, or any connections to ground other than as required or permitted elsewhere in the Code?”
Thermal insulation shall not be installed above a recessed luminaire or with 3 inches of the recessed luminaires' enclosure, wiring compartment, ballast, transformer, LED driver, or power supply, unless the luminaire is identified as ______ ?
Where more than three current-carrying conductors are installed within a raceway for electrically driven or controlled irrigation machines, the signal and control conductors of the raceway or cable shall ________.
LEDs have unique and compelling characteristics that make them ideal for industrial lighting applications. But there are a variety of misconceptions about LEDs, how well they work, how long they last, and more. Digital Lumens developed this whitepaper to dish up the facts around LEDs and address some common misunderstandings....More
An arc flash is associated with the explosive release of energy caused by an electrical arc, due to either a phase-to-ground or a phase-to-phase fault. This kind of fault can result from many factors – a dropped tool, accidental contact with electrical systems, buildup of conductive dust, corrosion or improper work conditions.....More
Abstract: In this webinar, Mike will not only explain the current NEC requirements for GFCIs and AFCIs, but he'll explain how they operate, what causes their premature failure, and when they won't provide the safety protection you might have thought they would.