AC – Alternating Current
An electric current that alternates or reverses the polarity in a cyclical manner (in the UK 50HZ i.e. reverses 50 times per second).
Actuator
The mechanism of a switch, which operates the contacts.
Alternator
An electric generator designed to produce alternating current. Usually consists of rotating parts, which created the changing magnetic field to produce the alternating current.
AM
Amplitude modulation.
Ambient Temperature
The surrounding temperature of an area.
Ampacity
Current handling capability expressed in amperes. The maximum current a conductor can carry without being heated beyond a safe limit.
Ampere (Amp)
A type of electric current produced by one volt applied across a resistance of one ohm. It is also equal to the flow of one coulomb per second.
Amplifier
An electrical circuit that increases the power, voltage or current of an applied signal.
Amplitude
The magnitude of a current or voltage. It can be the maximum, minimum, average or RMS value of an alternative current (AC) signal. These four magnitudes are the same for a direct current (DC) signal.
Analog Signal
An electrical signal that varies continuously, not having discrete values. Analog signals are copies or representations of other waves in nature. An analog audio signal, for example, is a representation of the pressure waves, which make up audible sound.
Anode
A positive electrode. The point where electrons exit from a device to the external electric circuit.
Appliance
Utilisation equipment, generally other than industrial, normally built in standard sizes or types, that is installed or connected as a unit to perform one or more functions such as clothes washing, air conditioning, food mixing, deep frying etc.
Battery
A group of two or more cells connected together to provide electrical current. Sometimes also used to describe a single cell, which converts chemical energy to electrical current.
Balanced Load
An alternating current power system of more than two current carrying conductors which all carry the same current.
Bonding
The connection of two or more points to reduce any difference of potential.
Branch Circuit
The circuit conductors between the final over current device protecting the circuit and the outlet(s).
Break
The act of the operating of an electrical circuit.
Breakdown Voltage
The voltage at which the insulation between two conductors will fail and allow electricity to conduct or ‘arc’.
BS – British Standard
British Standard BS 7671 – also known as the IEE (Institute of Electrical Engineering) wiring regulations. Details the requirements for electrical installations and is the standard against which all NICEIC contractors are assessed. To enrol with NICEIC all electricians, and anyone they employ, must meet this national safety standard.
Capacitance
This is the ability of a dielectric material between conductors to store energy when a difference of potential exists between the conductors.
Capacitor
A device used to store electrical energy in an electrostatic field until discharge. The effectiveness of the device or its capacitance is measured in Farads.
Cell
A single device, which converts chemical energy into electrical current. Sometimes also referred to as a battery.
Certificate
Any electrician installing a new electrical installation (including a single circuit), altering, extending or adapting an existing circuit should issue the homeowner with electrical installation certificate or minor electrical installation works certificate to confirm the work complies with the requirements of BS 7671.
Charge
The measured amount of electrical energy that represents the electrostatic forces between atomic particles.
Circuit
An assembly of electrical equipment (socket outlets, lighting points and switches) supplied from the same origin and protected against over current by the same protective device(s). A full path of electrical current from a voltage source that passes completely from one terminal of the voltage source to another.
Circuit Breaker or RCBO
A device capable of making, carrying and breaking normal load currents and also making and automatically breaking, under pre-determined conditions, abnormal currents such as short-circuit currents. It is usually required to operate infrequently although some types are suitable for frequent operation.
Circuit Extensions
To extend or add on to an existing circuit to provide an additional power source.
Class I Equipment
Equipment in which protection against electric shock does not rely on basic insulation only, but which includes means for the connection of exposed-conductive-parts to a protective conductor in the fixed wiring of the installation. Class I equipment has exposed metallic parts, e.g. the metallic enclosure of washing machine.
Class II Equipment
Class II equipment, such as music systems, television and video players, in which protection against electric shock does not rely on basic insulation only, but in which additional safety precautions such as double insulation are provided, there being no provision for the connection of exposed metalwork of the equipment to a protective conductor, and no reliance upon precautions to be taken in the fixed wiring of the installation.
Cold Weather Ballast
Compact fluorescent light bulbs require a ballast to regulate the voltage of the electricity that is applied to the gas inside the lamp. Below freezing weather can adversely affect the electronic components in these ballasts, causing most compact fluorescent bulbs to appear dim in cold weather. Cold weather ballasts compensate for this problem and keep the bulb glowing brightly even in the coldest weather. For example, cold storage meat rooms.
Colour Rendering Index (CRI)
Measures the effect of a lamp’s spectrum on the colour appearance of objects. The higher the number is the truer the appearance of the light on objects.
Conductor
A material used to conduct electricity or heat.
Conductivity
The ability of a material to allow electrons to flow, measured by the current per unit of voltage applied.
Conduit
A tube or pipe that carries and protects electric wiring, this can be metal or plastic.
Consumer Unit / Fuse Box / Electricity Control Unit
A particular type of distribution board comprising a co-ordinated assembly for the control and distribution of electrical energy, principally in domestic premises, incorporating manual means of double-pole isolation on the incoming circuit(s) and an assembly of one or more fuses, circuit-breakers, residual current operated devices or signalling and other devices purposely manufactured for such use.
Continuous Load
A load where the maximum current is expected to continue for 3 hours or more.
Controller
A device or group of devices that serves to govern, in some predetermined manner, the electric power delivered to the apparatus to which it is connected.
Coupling
The transfer of energy (without direct electrical contact) between two or more cables or components of a circuit.
Correlated Colour Temperature
(CCT) measures light colour. Cool colours have higher Kelvin (see below in this Glossary for Kelvin) temperatures and are usually better for visual tasks. Warm colours have lower colour temperatures and are usually better for living spaces.
CPS
Abbreviation for cycles per second.
Current
The flow of electricity commonly measured in amperes.
Current Carrying Capacity
The maximum current a conductor can carry without being heated beyond a safe limit. See Ampacity.
Decibel (dB)
Decibels are used to express acoustic power. The decibel can express an actual level only when comparing with some definite reference level that is assumed to be zero dB.
Delta
In a three phase connection all three phases are connected in series thus forming a closed circuit.
Derating Factor
A multiplier used to reduce the current carrying capacity of conductors in more adverse environments, such as high temperature, or where multiple conductors are together in one conduit.
Device
A unit of an electrical system that is intended to carry but not utilise electric energy.
Dielectric
An insulating (non-conducting) medium. It is the insulating material between conductors carrying a signal in a cable. In coaxial cables it is between the centre conductor and the outer conductor. In twisted pair cables it is the insulation between conductors plus any surrounding air or other material.
Diode
A device having two terminals and has a low resistance to electrical current in one direction and a high resistance in the other direction.
Direct Current (DC)
Electrical current whose electrons flow in one direction only and is generally constant.
Dielectric Strength
The voltage an insulation can withstand before it breaks down.
Distribution Board
An assembly containing switching or protective devices (e.g. fuses, circuit-breakers, residual current operated devices) associated with one or more outgoing circuits fed from one or more incoming circuits, together with terminals for the neutral and protective circuit conductors. It may also include signalling and other control devices. Means of isolation may be included in the board or may be provided separately.
Earth
The British terminology for zero reference ground.
Earth Stake
See Grounded Conductor.
Efficiency
Output power divided by input power, work performed in ratio to energy used to produce it.
(EICR) Electrical Installation Condition Report
An electrical survey, known as a Electrical Installation Condition Report will reveal if electrical circuits are overloaded, find potential hazards in the installation, identify defective DIY work, highlight any lack of earthing or bonding and carry out tests on the fixed wiring of the installation. The report will establish the overall condition of all the electrics and state whether it is satisfactory for continued use, and should detail any work that might need to be done.
Electric Circuit
An arrangement of any of various conductors through which electric current can flow from a supply current.
Electrical Installation
Any assembly of electrical equipment supplied by a common source to fulfil a specific purpose.
Electrical Safety Regulations
NICEIC registered electricians have already helped to improve the standard of electrical work in the UK. A new electrical safety law, often referred to as Part P of the Building Regulations, has further enhanced the protection of homeowners and reduced the risk of electric shock when using electricity. The law, which applies to England and Wales aims to improve electrical safety in the home and prevent the number of accidents, which are caused by faulty electrical work. The law requires an electrician registered with a government-approved scheme, such as NICEIC, to carry out most electrical work in the home. After completion of any work your NICEIC registered electrician will issue you with a Building Regulations Compliance Certificate to prove it meets the required standards of Part P. You can only carry out electrical work yourself if you can inspect and test that it is safe for use. To comply with the law you must notify your local building control office before you begin any work and pay the appropriate fee for them to inspect the work.
Electricity
A form of energy produced by the flow of particles of matter and consists of commonly attractive positively and negatively charged atomic particles. A stream of electrons or an electric current.
Electrode
An anode or cathode conductor on a device through which an electric current passes.
Electromagnet
A coil of wire wound about a magnetic material, such as iron, that produces a magnetic field when current flows through the wire.
Electromagnetic
Referring to the combined electric and magnetic fields caused by electron motion through conductors.
Electromagnetic Field
Electric and magnetic force field that surrounds a moving electric charge.
Electron
A fundamental negatively charge atomic particle that rotates around a positively charge nucleus of the atom.
Electronic Ballasts
An electronic device that regulates the voltage of fluorescent lamps. Compared to older magnetic ballasts, electronic ballasts use less electricity and are not prone to the flickering and humming effects sometimes associated with magnetic ballasts.
Electrostatic
Pertaining to static electricity, or electricity at rest i.e. an electric charge.
Enclosure
The case of housing of an apparatus, fence or walls that prevent persons from accidentally contacting energising parts or to protect the equipment from physical damage.
Energising
Electrically connected to a source of potential difference.
Energy
The capacity for, or the ability to do, mechanical work. Electrical energy is measured in kilowatt hours for billing purposes.
Energy Saving Devices
Devices utilised and designed to more efficiently make use of energy sources while providing heating, cooling and light.
EMF
Electromotive force (voltage).
Equipment
A general term including materials, fittings, devices, appliances, fixtures, apparatus and the like used as a part of, or in connection with, an electrical installation.
Farad
A unit of capacity that will store one coulomb of electrical charge when one volt of electrical pressure is applied.
Fault
A short circuit in an electrical system.
Field
An area through which electric and/or magnetic lines of force pass.
Filament
The element inside a vacuum tube, incandescent lamp or other similar device.
Filter
A circuit element or components that allows signals of certain frequencies to pass and blocks signals of other frequencies.
Fixture
Any permanently connected light or other electrical device that consumes power.
Floating
Referring to a circuit, which has no connection to ground.
Fluorescent
The quality of having the ability to emit light when struck by electrons or another form of radiation.
Fluorescent Lamps
Fluorescent lamps produce light by passing electricity through a gas, causing it to glow. The gas produces ultraviolet light; a phosphor coating on the inside of the lamp absorbs the ultraviolet light and produces visible light. Fluorescent lamps produce much less heat than incandescent lamps and are more energy efficient. Linear fluorescent lamps are used in long narrow fixtures designed for such lamps. Compact fluorescent light bulbs have been designed to replace incandescent light bulbs in table lamps, floodlights and other fixtures.
Flux
The rate of transfer of energy.
FM
Frequency modulation.
Forward Voltage
The voltage that is applied across a semiconductor junction to permit forward current through that junction and the device. Forward voltage is also known as bias.
Frequency
The number of times a periodic action occurs in one second. Measured in Hertz.
Fuses
Removable devices that link a circuit at the fuse box. Fuse connections blow apart and break the circuit if an overload or short circuit occurs.
Gain
The increase of voltage, current or power over a standard or previous reading. Usually expressed in decibels.
Generator
A rotating machine which converts mechanical energy into electrical energy.
Global Warming
Global warming is the gradual increase in global temperatures caused by the emission of gases that trap the sun’s heat in the earth’s atmosphere.
GND
Ground
Grid
In an electrical system, a term used to refer to the electrical utility distribution network.
Ground
An electrical connection between a circuit and the earth. Also refers to a conductor connected to earth. In some instances, can refer to a central metallic point designated as having zero potential.
Grounded
A connected path to earth or to a conductive body that has a reference potential to earth.
Grounded Conductor
A circuit conductor that is grounded to become part of the electric circuit by design and intent.
Grounding Conductor
The conductor that is used by intent to connect the grounded circuit of an electrical wiring system or equipment to a grounding electrode with reference to earth.
Ground Loop
A completed circuit between shielded pairs of a multiple pair created by random contact between shields. An undesirable circuit condition in which interference is created by ground currents when grounds are connected at more than one point.
Ground Wire
A conducting connection, whether intentional or accidental, between an electrical circuit or equipment and the earth, or to some conducting body that serves in place of the earth.
Hard Wired
That part of a circuit, which is physically interconnected.
Heater
A heat source (gas or electric) used to adjust the temperature inside a dwelling from a cold to a warm condition.
Hertz (Hz)
The unit of frequency (not just electricity, but also, for example, sound waves).
Horsepower
A unit of power equal to 746 watts.
Impedance
The total opposition that a circuit offers to the flow of alternating current or any other varying current at a particular frequency.
Impulse
A current surge.
Incandescent Light Bulbs
Incandescent light bulbs produce light by passing electricity through a thin filament, which becomes hot and glows brightly. Incandescent light bulbs are less energy efficient that fluorescent lamps, because much of the electrical energy is converted to heat instead of light. The heat produced by these bulbs not only wastes energy but can also make a building’s air conditioning system work harder and consume more energy.
Inductance
The property of wire which stores electrical current in a magnetic field around the wire. By coiling wire the effect can be intensified.
Induction
The occurrence of a voltage, magnetic field or electrostatic charge being produced in an object from the source of such fields.
Induction Heating
Heating a conducting material by placing it in a rapidly changing magnetic field. The changing field induces electric currents in the material and losses account for the resultant heat.
Insulation
A material having a high resistance to the flow of electric current.
Insulator
Any material, which does not allow electrons to flow through it.
Insulation Stress
The molecule separation pressure caused by a potential difference across an insulator.
Interface
The method by which two devices or systems are connected and interact with each other.
Interrupter
An element designed to interrupt specific currents under specified conditions.
Intrinsically Safe
A device, instrument or component that will not produce any spark or thermal effects under any conditions that are normal or abnormal that will ignite a specified gas mixture. Electrical and thermal energy limits are at levels incapable of causing ignition. It is common practice to use external barriers with intrinsically safe installations.
Invertor
An electrical device, which is designed to convert direct current into alternating current.
Ion
An ion is a positively or negatively charged atom or molecule.
Isothermal
A process that is kept at a constant temperature.
Isolation
To be electrically separate. A measure of the strength of the dielectric providing the electrical division or separation.
Joule
A unit of work or energy equal to one watt for one second.
Junction Box
A metal or plastic box used to enclose cable joint connections.
Kelvin
Is a unit of measurement for temperature down to absolute zero.
Kilovolt
A unit of electrical potential equal to 1,000 volts.
Kilowatt
Real power delivered to a load (W x 1,000 VA).
Lag
The time delay between the output signal and the response time of the receiver of the signal.
Leakage
The undesirable passage of current over the surface of or through an insulator.
Leakage Current
A small current leaking from an output device in the off state caused by semiconductor characteristics i.e. computer/electronic equipment.
LED Lumen Maintenance
Measures the amount of light remaining at a given time. This optional metric is provided as a percentage of initial output at a fixed time.
Level
A measure of the difference between a quantity or value and an established reference.
Light Emitting Diode (LED)
A solid state light source component that emits light or invisible infrared radiation.
Line Drop
A voltage loss occurring between any two points in a power or transmission line. Such loss, or drop, is due to the resistance, reactance or leakage of the line.
Line Level
Refers to the output voltage level of a piece of electronic equipment.
Line Voltage
The value of the potential existing on a supply or power line.
Live Parts
Electric conductors, terminals or components that are uninsulated or exposed and an electric shock hazard exist.
Load
A device that consumes power from a source and uses that power to perform a function. The electrical demand of a process.
Loss
Energy or signal lost without accomplishing useful work.
Low Voltage (now normally referred to as Extra Low Voltage i.e. 12 volts)
A wiring system that provides power to some electronic devices operating on a voltage level much lower than the standard 230 volts. Such devices might be doorbells and intercoms/CCTV/alarm systems.
Lumens
Measure light output. The higher the number, the more light emitted.
Lumens Per Watt (lm/W)
Measures efficiency. The higher the number is the more efficient the product. Modern LEDs can be up to 120 lm/w.
LV
Low Voltage
mA
Milliamp or 1/1000 part of an amp. 1000 mA to 1 Amp.
Magnetic Field
A region of space that surrounds a moving electrical charge or a magnetic pole, in which the electrical charge or magnetic pole experiences a force that is above the electrostatic ones associated with particles at rest.
Make
To close an electrical circuit. To establish an electrical circuit through the closing of a contact, switch or other related device.
Manual Reset Switch
A switch in a controller that manually resets after exceeding the controllers limit.
Maximum Operating Temperature
The maximum temperature at which a device can be safely operated.
Maximum Power Rating
The maximum watts that a device can safely handle, Watts/KW/Amps.
Mean Temperature
The average temperature of a process.
Metal Enclosed
Surrounded by a metal case of housing, usually grounded.
Metalclad
Devices in which the conducting parts are entirely enclosed in a metal casing.
Microamp
One millionth of an amp.
Micron
One millionth of a meter.
Microvolt
One millionth of a volt.
Mil
One thousandth of an inch.
Milliamp
One thousandth of an amp.
Millimeter
One thousandth of a meter.
Millivolt
One thousandth of a volt. The difference in potential needed to cause a current of one milliampere flow through a resistance of one ohm.
Momentary Switch
A switch with contacts that are made with actuating force and released when that force is removed.
Neutral
The return path to ground to complete a circuit.
Ohm
The unit of measure for electrical resistance. One ohm is equal to the current of one ampere, which will flow when a voltage of one volt is applied.
Ohmmeter
A meter used to measure electrical resistance in units of ohm.
Open Circuit
An electrical circuit that is not made. Contacts, switches or similar devices are open and preventing the flow of current.
Open Circuit Earth
The wire earthing your electrical devices has been disconnected.
Operating Temperature
The range of temperature over which a device may be safely used. The temperature range, which the device has been designed to operate.
Outlet
A point on the wiring system at which current is taken to supply portable electrical devices i.e. 13 Amp socket outlet.
Output
The useful power or signal delivered by a circuit or device.
Overcurrent
Electrical current (in amps) that exceeds the maximum limit of a circuit. May result in risk of fire or shock from insulation damaged from heat generated by overcurrent condition.
Overload
Operation of equipment in excess of normal, full load rating or of a conductor in excess of rated ampacity that, when it persists for a sufficient length of time, would cause damage or dangerous overheating. A fault such as a short circuit or earth fault is not an overload.
Over Voltage
A voltage above the normal rated voltage or the maximum operating voltage of a device or circuit.
Ozone
Extremely reactive form of oxygen, normally occurring around electrical discharges and present in the atmosphere in small but action quantities. In sufficient concentrations it can break down certain rubber insulations under tension (such as bent cable).
Parallel Circuit
In parallel circuits the components are so arranged the current divides between them. The voltage remains the same but the current may vary. The circuits in your home are wired in parallel.
Part P
The specific section of the Building Regulations for England and Wales that relates to electrical installations in domestic properties. Part P provides safety regulations to protect householders, and requires most domestic electrical work to be carried out by government-registered electricians, or to be inspected by Building Control officers.
PAT – Portable Appliance Testing
Inspection and testing of electrical equipment including portable appliances, moveable equipment, hand held appliances, stationary equipment, fixed equipment/appliances, IT equipment and extension leads.
Peak
The maximum instantaneous value of a varying current or voltage.
Phase
The time based relationship between a reference and a periodic function. In the UK single phase or 3 phase.
PIR – Periodic Inspection Report – known now as EICR (see Glossary entry)
An electrical survey, known as a Periodic Inspection Report (PIR) will reveal if electrical circuits are overloaded, find potential hazards in the installation, identify defective DIY work, highlight any lack of earthing or bonding and carry out tests on the fixed wiring of the installation. The report will establish the overall condition of all the electrics and state whether it is satisfactory for continued use, and should detail any work that might need to be done.
Polarity
Magnetically, opposite poles, north and south. In electricity, oppositely charged poles, which are positive and negative.
Portable Equipment
Electrical equipment which is less than 18 kg in mass and is intended to be moved while in operation or which can easily be moved from one place to another, such as a toaster, food mixer, vacuum cleaner, fan heater.
Power
The rate at which work is performed or that energy is transferred. Usually expressed in watts or kilowatts. Power equals the product of voltage and current.
Power Dissipation
The amount of power that is consumed and converted to heat.
Power Loss
The difference between the total power delivered to a circuit, cable or device and power delivered by that device to a load.
Power Ratio
The ratio of power appearing at the load to the input power.
Power Supply
The part of a circuit that supplies power to the entire circuit or part of the circuit. Usually a separate unit that supplies power to a specific part of the circuit in a system.
Prospective Fault Current
The value of overcurrent at a given point in a circuit resulting from a fault between live conductors.
Pulse
A current or voltage which changes abruptly from one value to another and back to the original value in a finite length of time. Used to describe one particular variation in a series of wave motions.
Quartz
A form of silicone dioxide. Commonly used in the making of radio transmitters and heat resistant products.
Quartziodine Lamp
A high intensity incandescent lamp with a quartz bulb containing an inert gas of iodine or bromine vapour.
Rated Voltage
The maximum voltage at which an electric component can operate for extended periods without undue degradation or safety hazard.
RCD – Residual Current Device
This is not just a manually operated isolating switch, but a very sensitive safety device which cuts off in fractions of a second if it senses an earth fault. In the UK the standard is 30 mA in balance between live and neutral.
Reactance
A measure of the combined effects of capacitance and inductance on an alternating current. The amount of such opposition varies with the frequency of the current. The reactance of a capacitor decreases with an increase in frequency.
Rectifier
A device that converts AC voltage to DC voltage.
Relay
A solid state relay is a switching device that completes or interrupts a circuit electrically and has no moving parts. A mechanical relay is an electromechanical device that closes contacts to complete a circuit or opens contacts to interrupt a circuit.
Resistance
In dc circuits, the opposition a material offers to current flow, measured in ohms. In ac circuits, resistance is the real component of impedance and may be higher than the value measured at dc.
Resistor
Any device of material that limits the flow of current when voltage is applied.
Response Time
The amount of time it takes for a device to react to an input signal.
Ring Final Circuit / Ring Main / Ring
A final circuit connected in the form of a ring and connected to a single point of supply rated at 32 Amps with unlimited socket outlets within 100 square meters.
SELV
Separated Extra-Low Voltage. An extra-low voltage system, which is electrically separated from Earth and from other systems in such a way that a single fault cannot give rise to the risk of electric shock.
Semiconductor
A material possessing electrical conductivity that falls somewhere between that of conductors and insulators.
Series Circuit
A circuit in which the components are arranged end to end to form a single path for current.
Service
The conductors and equipment for delivering electric energy from the serving utility to the wiring system of the premises served.
Service Cable
Service conductors made up in the form of a cable and a Cut Out fuse.
Static Charge
An electrical charge that is bound to an object. An unmoving electrical charge.
Supply Current
The amount of amps or milliamps needed to maintain operation of a control or device.
Supply Voltage
The range of voltage needed to maintain operation of a control or device.
Surge
A temporary and relatively large increase in the voltage or current in an electric circuit or cable. Also called transient voltage or spike.
Switches
Circuit interruption devices used to control the flow of electricity to lights, appliances and outlets.
Systems Capacity
Represents the ability of a system to meet its customers’ needs, or meet the electrical demand of its customers. System capacity is provided by generators, transmission lines, distribution networks and load management.
Thermostat
A mains or low voltage electronic switching device that monitors temperatures inside the home and turns on and off the heating or cooling system in the home.
Three Phase Power
Three separate outputs from a single source with a phase differential of 120 electrical degrees between any two adjacent voltages or currents.
Transfer Switch/Mechanical Change Over Switch
An electronic or mechanical device that under certain conditions will disconnect from one power source and connect to another power source i.e. a standby generator.
Transformer
A static electrical device which by electromagnetic induction transfers electrical energy from one circuit to another circuit usually with changed values of voltage and current in the process.
Transient
A sudden and unwanted increase or decrease of supply voltage or current.
Transient Protection
Protective circuitry to guard against spikes that might be induced on the supply line.
Transistor
A device incorporating semiconductor material and suitable contacts capable of performing electrical functions, such as, voltage, current or power amplification, with low power requirements.
Turn Ratio
The ratio of the number of turns in the high voltage winding to that in the low voltage winding.
Two Gang Outlet Box/Plate
This is an outlet box/plate that will allow you to use two electrical items (two receptacles, two switches or one of each). The more gangs the more devices.
Vacuum
Pressure that is less than atmospheric pressure.
V
Volt
VA
Volt ampere. Measure of apparent power in a reactive circuit found by multiplying the voltage by the current not to be confused with watts. This is normally represented as power in KVA.
Velocity
The speed or time rate of change of displacement.
Ventilated
Provided with the means to permit circulation of air sufficient to remove an excess of heat, fumes or vapours.
Volt
A unit of electromotive force that measures the amount of electrical pressure.
Voltage
Electrical potential of electromotive force that causes current to flow, expressed in volts.
Volt Amps
Amps are the term used to describe the flow of current. Volts are the electrical pressure applied to a circuit to make the current flow. The formula for power or watts is volts times amps. Volt Amps would be Watts.
Voltage Drop
The voltage developed across a component or conductor by the current flow through the resistance or impedance of the component or conductor.
Voltage – Extra-Low
Normally not exceeding 50 V a.c. or 120 V ripple-free d.c., whether between conductors or to earth.
Voltage Rating
The highest voltage that may be continuously applied to a cable construction in conformance with standards or specifications.
W
Symbol for watt or wattage.
Watt
A unit that measures the amount of electrical power.
Wiring
A distribution network of wire that conducts electricity to receptacles, switches and appliances throughout a building/home to provide electricity where needed.
R.S. Electrical Services
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Odd Down
Bath
Somerset
BA2 2PP
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