| A | B |
|---|
| Apparatus | An assembly of machines used together to do a particular job. |
| Arc | The flow of electrical current through a gas such as air from one pole to another pole. |
| Combustible | Capable of easily igniting and rapidly burning; used to describe a fuel with a flash point at or above 100°F. |
| Competent person | A person who can identify working conditions or surroundings that are unsanitary, hazardous, or dangerous to employees and who has authorization to correct or eliminate these conditions promptly. |
| Concealed receptacle | The electrical outlet that is placed inside the structural elements of a building, such as inside the walls. The face of the receptacle is flush with the finished wall surface and covered with a plate. |
| Confined space | A work area large enough for a person to work, but arranged in such a way that an employee must physically enter the space to perform work. A confined space has a limited or restricted means of entry and exit. It is not designed for continuous work. Tanks, vessels, silos, pits, vaults, and hoppers are examples of confined spaces. See also permit-required confined space |
| Cross-bracing | Braces (metal or wood) placed diagonally from the bottom of one rail to the top of another rail that add support to a structure. |
| Electrical distribution panel | Part of the electrical distribution system that brings electricity from the street source (power poles and transformers) through the service lines to the electrical meter mounted on the outside of the building and to the panel inside the building. The panel houses the circuits that distribute electricity throughout the structure. |
| Excavation | Any man-made cut, cavity, trench, or depression in an earth surface, formed by removing earth. It can be made for anything from basements to highways. See also trench.. |
