National Electrical Code Articles and Information

All answers are from Article 100.

1.   Continuous duty: operates at a substantially constant load for an indefinitely long time.
Intermittent duty:  operates alternatively between load and no load, load and rest, or a combination of the three.
Periodic duty: intermittent duty in which the load conditions regularly recur.
Short-time duty: operates at a substantially constant load for a time that is definite, short, and specified.
Varying duty: the loads and intervals of operation change.

2.   The definition isn't just a house or apartment--it's more inclusive than that. A dwelling is one or more rooms for the use of one or more persons as a housekeeping unit with space for eating, living, and sleeping and permanent provisions for cooking and sanitation.

3.   One-family, two-family, and multi-family.

4.   Many people confuse "energized" with "on" and "de-energized" with "off." That can literally be a fatal mistake. Something is "energized" any time it's connected to a source of power. A disconnecting means and a switch each serve different purposes.

5.   An explosion-proof device contains the flame of an explosion that occurs within it. It does not protect equipment from an explosion.

6.   Wiring is accessible if a qualified person can expose it without damaging the structure or finish of the building. Wiring is exposed if a person can touch it or approach it at an unsafe distance. Exposed wiring is, by definition, "not suitably guarded, insulated, or protected." Sometimes, you must expose wiring to work on it. That requires the wiring to be accessible. However, it should not be exposed when you are done working on it. It just needs to be accessible.

7.   A garage is a building or portion of a building in which one or more self-propelled vehicles can be kept for use, sale, storage, rental, repair, exhibition, or demonstration purposes.

8.  This rating is the highest current (at rated voltage) that a protection device is intended to interrupt under standard test conditions. Note: devices of the same interrupt rating may not be suitable for the same purpose.

9.   Labeled devices have a marking or label showing they have been tested to meet the criteria of the labeling authority.
Listed devices have also been tested, and are on a list—but don’t have the label to prove it.

10. Damp locations are protected from weather and saturation, but not moisture.
Dry locations are protected from weather, saturation, and moisture--or are normally not subject to them.
Wet locations are subject to saturation with water or other liquids.