Electrical Terms and Definitions
Please select from the menu above
An Arc Fault Circuit Interrupter (AFCI) is a circuit breaker that breaks the circuit when it detects an electric arc in the circuit it protects and shuts off the power so to prevent electrical fires.
- Ampere or Amp
Ampere or amp (symbol: A) is the unit of electrical current. The current is defined as the amount of charge that flows past a give point, per unit of time. The symbol I is used for current in equations and A is the abbreviation for ampere.
Capacitor: Is a passive electronic component that consists of two conductive plates separated by an insulating dielectric. A voltage applied to the plates develops an electric field across the dielectric and causes the plates to accumulate a charge. When the voltage source is removed, the field and the charge remain until discharged, storing energy.
Current: Movement of electricity along a conductor. Current is measured in amperes.
Diode: An electrical device that will allow current to pass through itself in one direction only.
- Direct Current ( DC )
Direct Current (DC): A steady flow of electrons moving steadily and continually in the same direction along a conductor from a point of high potential to one of lower potential. It is produced by a battery, generator, or rectifier.
Generator: A device which converts mechanical energy into electrical energy.
A ground fault circuit interrupter (GFCI) is a device that shuts off power to the circuit when it detects that current is flowing along an unintended path, such as through water or a person.
Ground: A ground occurs when any part of a wiring circuit unintentionally touches a metallic part of the machine frame.
Inductance: The property of an electric circuit by which an electromotive force (voltage) is induced in it by a variation of current either in the circuit itself or in a neighboring circuit.
Inductor: A coil of wire wrapped around an iron core.
Insulator: A substance or body that resists the flow of electrical current through it. Also see “Conductor:’
Ohm: The standard unit for measuring resistance to flow of an electrical current. Every electrical
conductor offers resistance to the flow of current, just as a tube through which water flows offers resistance to the current of water. One ohm is the amount of resistance that limits current flow to one ampere in a circuit with one volt of electrical pressure.
- Open Circuit
Open Circuit: An open or open circuit occurs when a circuit is broken, such as by a broken wire or open switch, interrupting the flow of current through the circuit. It is analogous to a closed valve in a water system.
- Parallel Circuit
Parallel Circuit: A circuit in which the circuit components are arranged in branches so that there is a separate path to each unit along which electrical current can flow.
Potentiometer: A variable resistor used as a voltage divider.
Resistor: A device usually made of wire or carbon which presents a resistance to current flow.
- Series-Parallel Circuit
Series-Parallel Circuit: A circuit in which some of the circuit components are connected in series and others are connected in parallel.
Switch: A device which opens or closes electrical pathways in an electrical circuit.
Transformer: Is a device made of two coil windings that transfers voltage from one coil to the next through electromagnetic induction. Depending upon the number of windings per coil, a transformer can be designed to step – up or step – down its output voltage from its input voltage. Transformers can only function with alternating current (AC).
Volt: A unit of electrical pressure (or electromotive force) which causes current to flow in a circuit. One volt is the amount of pressure required to cause one ampere of current to flow against one ohm of resistance.
Voltage: Force which is generated to cause current to flow in an electrical circuit. It is also referred to as electromotive force or electrical potential. Voltage is measured in volts.
Watt: A unit of measure for indicating the electrical power applied in a circuit. It is obtained by multiplying the current (in amperes) by the electrical pressure (in volts) which cause it to flow. That is: watts = amperes x volts.