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ACCURACY vs PRECISION of MEASUREMENTS
AFCIs ARC FAULT CIRCUIT INTERRUPTERS
ALUMINUM SECs & WIRING
ALUMINUM WIRING HAZARDS & REPAIRS
AMPS & VOLTS DETERMINATION
AMPACITY - the LIMITING FACTOR
APPLIANCE EFFICIENCY RATINGS
BACKUP ELECTRICAL GENERATORS
BOOKSTORE - ELECTRICAL
BUILDING SAFETY HAZARDS GUIDE
Cadet & Encore Heater Recall
CIRCUIT BREAKER FAILURE
CIRCUIT BREAKER SIZE for A/C or HEAT PUMP
Classified CIRCUIT BREAKER WARNING
CORROSION in ELECTRICAL PANELS
CORROSION & MOISTURE SOURCES in PANELS
CUTLER HAMMER PANEL FIRE
DEFINITIONS of ELECTRICAL TERMS
DIRECTORY OF ELECTRICIANS
DMM Digital Multimeter, How to Use
ELECTRIC METERS & METER BASES
ELECTRIC MOTOR DIAGNOSTIC GUIDE
ELECTRIC MOTOR OVERLOAD RESET SWITCH
ELECTRIC PANEL AMPACITY
ELECTRIC PANEL INSPECTION
ELECTRIC PANEL MOISTURE
Electric Power Frequency Table
ELECTRICAL DISTRIBUTION PANELS
ELECTRICAL GROUND SYSTEM INSPECTION
ELECTRICAL SERVICE DROP
ELECTRICAL SERVICE ENTRY WIRING
EMF RF FIELD & FREQUENCY DEFINITIONS
FEDERAL PACIFIC FPE HAZARDS
FIRE SAFETY Checklist, CPSC
GFCI PROTECTION,Testing GFCIs AFCIs
HEATING COST FUEL & BTU Cost Table
HEAT TAPE USAGE GUIDE
Hertz - Definitions of KHz MHz GHz THz
KNOB & TUBE WIRING
LIGHTING, EXTERIOR GUIDE
LIGHTING, INTERIOR GUIDE
LIGHTNING PROTECTION SYSTEMS
LOW VOLTAGE BUILDING WIRING
LOW VOLTAGE TRANSFORMER TEST
MAIN DISCONNECT AMPACITY
MOISTURE SOURCES in PANELS
MURRAY SIEMENS Recall
PHOTOVOLTAIC POWER SYSTEMS
PUSHMATIC - BULLDOG PANELS
REMOTE ELECTRIC POWER, PHOTOVOLTAIC
RUST in ELECTRICAL PANELS
SAFETY for ELECTRICAL INSPECTORS
SE CABLE SIZES vs AMPS
SIEMENS MURRAY Recall
UNDERGROUND SERVICE LATERALS
VOLTS / AMPS MEASUREMENT EQUIP
WIND ENERGY SYSTEMS
WIND TURBINES & LIGHTNING
ZINSCO SYLVANIA ELECTRICAL PANELS
Home electrical wiring basics & definitions: this article answers basic questions about electricity and electrical wiring such as "What is an electrical circuit" and what is a "short circuit".
Green links show where you are. © Copyright 2013 InspectAPedia.com, All Rights Reserved. Author Daniel Friedman.
Readers of this article should also see ELECTRICAL DEFINITIONS. This website provides information about a variety of electrical hazards in buildings, with articles focused on the inspection, detection, and reporting of electrical hazards and on proper electrical repair methods for unsafe electrical conditions. Critique and content suggestions are invited. Credit is given to content editors and contributors. Sketch at page top courtesy of Carson Dunlop Associates.
Every electric circuit has four basic parts:
Where does Electricity in a Building Come From?
The electrical panel provides a place for mounting of fuses or circuit breakers which protect the building wiring from overheating and short circuits as a way to reduce fire risk. Inside of a building electrical power is distributed to various rooms through individual circuits, each of which is fed from the electrical panel(s).
However, for practical purposes, the source of electricity at an individual home or other building may be thought of as the circuit breaker panel or fuse box from which electrical power is distributed throughout a home or other building. Junction boxes and wall outlets may be thought of as secondary sources of electrical power since they convenient points at which a building occupant can connect electrical devices anywhere in a building.
See ELECTRICAL DEFINITIONS for definitions of "Volts".
Electrical Conductors are the wires that carry the electric energy to the point at which it will be used. Conductors offer little (but not zero) resistance to current flow because atoms in the metals they are made of have lots of free electrons and therefore can transport it efficiently.
The fourth element in an electrical circuit is a means of controlling the energy. This is a device that can interrupt and restore current flow as desired by the user. Switches used in home electric systems control current flow by inserting a very high resistance (air gap) in the circuit to stop the current flow and by) removing the resistance (closing the air gap) to start current flowing again.
A basic principle of electrical wiring is that switches should always be wired into the hot (black or red) line leading directly to a device or outlet. When switches in the hot line are turned off, no hot line power is present in the load device. This greatly reduces the possibility of injury or damage resulting from accidental grounding.
An open circuit is a fault that cuts off current flow in a circuit. The break that causes the open circuit may be in the hot line, the neutral line, or the load. An open circuit appears to be off. The break that causes an open circuit may be quite small. Vibration or even changes in temperature may suddenly turn the circuit on again. When looking for the cause of an open circuit, be sure power is off at the source.
What are the definitions of AC and DC Electrical Current?
The electrical energy that flows in circuits and operates loads can be generated in either of two different forms. One form is called alternating current (AC); the other form is called direct current (DC).
Alternating current is almost universally used for home electric power and is, therefore, the kind this article is primarily concerned with. In an AC circuit, the amount of voltage applied to the circuit is constantly changing from zero to a maximum and back to zero in one direction and then from zero to maximum and back to zero in the other direction. The maximum voltage is set by the generating plant.
Direct current is most commonly found in homes in the form of electrical energy stored in batteries. In a DC circuit, the amount of voltage and the direction of application are constant. The amount of voltage is determined by the type and size of battery. The direction of current flow is also constant and, as in AC circuits, the amount of current flow is determined by the load resistance.
DEFINITIONS of ELECTRICAL TERMS defines alternating current and direct current in more detail.
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