Electrical Code Guide PDF

Electrical code - necessary for protecting people and property from the improper use of electricity National Electrical Code (NEC) - set of specifications and standards 1897 - NEC was established National Fire Protection Association (NFPA) – 1911, sponsor of the NEC and continues to act in this cap...

Electrical code - necessary for protecting people and property from the improper use of electricity National Electrical Code (NEC) - set of specifications and standards 1897 - NEC was established National Fire Protection Association (NFPA) – 1911, sponsor of the NEC and continues to act in this capacity NEC is revised every three years Canadian Standards Association (CSA) - publishes and administers the Canadian Electrical Code (CEC) Canadian Electrical Code Committee - develops the Canadian Electrical Code The CEC is revised every four years Grandfather clause - outdated electrical, use if they are not regarded as hazardous Underwriters Laboratory, Inc. (UL) - not-for-profit product safety testing ETL Testing Laboratories, Inc., - independent testing company National Electrical Manufacturing Association (NEMA) - leading trade association in the United States Council for Harmonization of Electrotechnical Standards of the Nations of the Americas - founded in 1992, promote the development of harmonized electrotechnical codes Licensing - person must have a minimum number of years of experience working Permits - issued before any electrical installations may be made on a project Electrical construction drawings - layout and design of an electrical installation Symbols - represent lighting and power distribution components One line - conductors extending between two symbols Single line without any additional identification - two-wire set of conductors Single line with three slashes - three-wire set of conductors and so on Power - delivered by the utility company to the user Supply voltage - nominal voltage because it varies slightly 90 to 105% - nominal voltage System voltages - principle voltages Medium and high voltage systems - above 600 V Low voltage systems - less than 600 V Higher voltage - smaller conductor sizes Ungrounded conductor - current-carrying conductor, hot or live conductor Grounded or neutral conductor - connecting the ungrounded conductor to ground Grounding conductor – provides additional protection or grounding protection Before about 1945 - two conductors were used to feed electrical energy Today - three conductors are used to deliver electrical energy Y – high leg or wild leg 120 V AC, 1-2W - basic system voltage, first electrical services, 6000 VA (50 A) 120/240 V AC, 1-3W - common residential electrical service, limited basis in light 208 Y/120 V AC, 3-4W - older electrical service, small commercial buildings 240 /120 AC, 3-4W - fairly common electrical service, commercial and industrial buildings 600Y/346 V AC, 3-4W – less common electrical service, large commercial and industrial building 120/240 V but is sometimes referred to as 110/220 V, 115/230 V or 125/250 V System voltage - target voltage Utilization voltage - anticipated voltage drops Voltage drop - current flows from the service equipment Line voltage – measured voltage at an outlet or connection Maximum voltage - highest voltage to which a wiring device can be exposed Shared neutral or Common neutral - neutral conductor Load balancing - practice of dividing loads System grounding - protection against electrical shock Equipment grounding - connects the noncurrent-carrying metal components of equipment Equipment-grounding conductor - bare conductor or a green-colored Bonding - installing an additional grounding conductor or by permanently joining metal components in a circuit bonding jumpers - good bond, good connection between the metal components Double insulation - appliance or power tool protects the user from electric shock