NEC in the Facility

Commonly misunderstood/misapplied terms, Part 3.

Did you know there’s no such thing as a wirenut? What people usually mean by this misuse of a trade name is a twist-on pressure connector. Other commonly misused terms include:

• Cutout box. This is a specific kind of enclosure. First of all, it's surface-mounted. A box that isn't designed for surface mounting isn't a cutout box. A cutout box also has swinging doors (or covers) secured directly to the walls of the box, and these doors (or covers) telescope with the walls of the box.
• Dead front. This doesn't mean the front has no door. It means a person on the operating side of the equipment isn't exposed to live parts.
• Dust-tight. A dust-tight enclosure may not be suitable for a high dust area. Why is this? The term means dust will not enter under specified test conditions. It doesn't mean dust absolutely cannot enter. You may need something beyond dust-tight to meet the Chapter 5 (Special Occupancies) requirements of your particular application.
• Duty. Intermittent, periodic, short-time, and varying are all specific types of noncontinuous duty. Each has its own definition. This matters, especially when dealing with motors or utilization factor.