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Auxiliary circuit. CircrLit for transmission ofsignals intended for control, detection, supervision or measulement of the frLnctrunrlstatus ofa llrain circuit.
Back-up protection, Protection of a device by overcurent co-ordination between that device and an overcurent protective device OCPD in series with it, generally but not necessarily on the supply side. This prevents ary I. NOTE: In this standard. A pat providing a dcfined degree ofprotection against contact with live parts from any usual direction of access. Basic insulation.
Insulation applied to live parls to provide basic protection and which does not necessarily include insulation used exclusively for functional purposes. Basic protection. Protection against electric shock under fault-free conditions.
NOTE: For low voltage installations. Basin of fountain. A basin not intended to be occupied by persons and which cannot be accessed reached by persons without the use ofladders or similar means.
For basins offountains which may be occupied by persolls, the requirements for swimrring pools apply. Bonding conductor. A protective conductor providing equipotential bonding. A set of interconnected conductive parts that provide a path for currents at frequencies from direct cunent DC to radio frequency RF intended to divert. Bonding ring conductor BRC! Abus eathing conductor in the form ofa closed ring. NOTE: Normaily the bonding dng conductor, as paft of the bonding network, has multiple con[ections to the common bonding network CBN that improves its performance.
Non-stationary unit, intended to accommodate equipment generally for pleasure or demonstration purposes. Building void, accessible, A space within the structure or the components of a building accessible only at certain points.
Such voids include the space within partitions, suspended floors, ceilings and cefiain types ofwindow frame, door frame and architrave. Building void, non-accessible. A space within the structure or the components of a building which has no ready rleans of access. Cables are said to be bunched when two or more are contained within a single conduit, duct, ducting.
Busbar trunking system. A type-tested assembly, in the form of an enclosed conductor system comprising solid conductors separated by insulating material. The assembly may consist ofunits such as: - busbar trunking units, with or without tap-off facilities - tap-off units where applicable - phase-tmnsposition, expansion, building-movement, flexible, end-feedir anrl adaptor units NOTE: Othcr systern components may include tap-offunits.
Bonding conductor connected in parallel with the screens ofcables. Cable channel. A cable channel may or may not form part ofthe building construction'. Cable cleat. A component of a support system, which consists of elements spaced at intervals along tl. Cabte coupler. A means of enabling the comection or disconnection, at will, of two flexible cables. Cable ducting. An enclosure of metal or insulating material, other than conduit or cable trurking, intended for the protection of cables which are drawn in after ercction ofthe ducting,.
Cable ladder. A cable support consisting of a series of transverse supporting elements rigidly fixed to main longitudinal supporting membels. Cable tray. A cable support consisting ofa continuous base with raised edges and no covering.
A cable tray may or may not be perforated. Cable trunking. A closed enclosure normally of rectangular cross-section, of which one side is removable or hilged, used for the protection ofcables and for the accommodation ofother electlical equipment. Cable tunnel. A trailer leisure accornmodation vehicle, used for touring, designed to meet the requirements for the colstruction and use ofroad vehicles see also definitjons of Motor caravan and Leisure accot.
Caravan pitch. Plot of ground intended to be occupied by a leisure accommodation vehicle'. Caravan pitch electrical supply equipment. Equipment that provides means of connecting and disconnectilg supply cables from leisure accommodation vehicles or tents with a mains electrical supply. Cartridge fuse link. A device comprising a fuse elernent or two oI more fuse elements connected in parallel see fuse link.
A system supplying the required emergency powel to essertial safety equipmert. Central power supply system low power output. Circuit, An assembl , of electrical equipment supplied from the same origin and protected agatnsi or ercurrenr b!
A device capable of n. It is usually required to operate inftequently although some tlpes are suitable for frequent operation'. Circuit-breaker, Instantaneous trip ICB. Circuit-breaker which only fulfils the short-circuit pofiion of overcurrent protection. Circuit-breaker, linked. A circuit-breaker the contacts of which are so aranged as to make or break all poles simultaneously or in a definite sequence. Circuit protective conductor cpc.
A protective conductor connecting exposed-conductive-parts of equipment to the main eathing termilal. Class I equipment.
Equipment in which protection against electdc shock does not rely on basic insulation on1y, but which includes ryreans for the connection ol exposed-conductive-parts to a protective conductor in the fixed wiring ofthe installation see BS EN Class II equipment. Equipment in which protection against electdc shock does not rely on basic insulation only, but in which additional safity precautions such as supplementary insulation are provided, there being no provision for the connection ofexposed metalwork ofthe equipment to a plotective conductor, and no reliance upon plecautions to be taken ir the fixed wiring ofthe installation see BS EN Ctass III equipment.
Combined short-circuit current capability. Maximum shofi-circuit cu-rent which can be handled by two shot- circuit protective devices in series.
Combined short-circuit protection. Equipotential bonding system providing both protective equipotential bonding and functional equipotential bonding'. Complementary floor heating, Direct heating system integrated into the ffoor constructiol, for example, in the border zones close 1o outer walls, which complements the heat dissipation ofa thermal storage floor heating system. Conditional short-circuit current, Prospective current that a circuit or a switching device, protected by a specified short-circuit protective device, can satisfactodly withstand for the total operating time ofthat device under specified conditions ofuse and behaviour,.
Conducting location with restricted movement. Alocation comprisedmainly ofmetallic or conductive surrounding par. The part of a cable coupler or of an appliance coupler which is provided with female contacts and is intended to be attached to the end ofthe flexible cable remote frorn the supply. Consumer unit may also be known as a consumer control unit or electricity control unit. A parlicular type of distribution board comprising a type-tested co-ordinated assembly for the control and distdbution of electrical energy, principally in domestic premises, incorporating manual means of double-pole isolation on the incoming.
Continuity of service. The extent to which the operation of an electrical system approaches the intended state of freedom from supply inteffuplion. Maximum ms voltage which may be continuously applied to an sPD's mode ofprotection.
Switching device or equipment capable of operation other than by hand, but with or without local manual operating means. Conventional impulse withstand voltage, The peak value olan impulse test voltage at which insulation does not show any disruptive discharge when subjected to a specified numbel ofapplications ofimpulses ofthis value, under specified conditions.
Co-ordination of electrical equipment. Current-carrying capacity of a conductor. The maximum curent which can be carried by a conductor under specified conditions without its steady-state tempemture exceeding a specified value. Current-using equipment. Equipment which convefis electdcal energy into another form of energy, such as light, heat or motive power.
I Danger. Risk ofinjury to persons and livestock where expected to be present ftom: i fire, electric shock, burns, arcing and explosion arising from the use ofelectrical energy, and ii mechanical movement of electrically controlled equipment, in so far as such danger is intended to be prevented by electrical emergency switching or by elect cal switching for mechanical maintenance ofnon- electdcal parls of such equipment.
Deliberate decision not to comply fully with the requirements ofthis Standard, for which the designer must declare that the resultant degree of safety is not less than that achievable by full colt.
Design current ofa circuit. The magnitude ofthe cunent rms value forAC to be caffied by the circuit in notmal setvice. Device for connecting a luminaire DCL. Sys'tem comprising an outlet and a connector provicling a fixed lumillaire with electrical connection to and disconnection from a fixed installation but not providing mechanical suppoft for a luminaire.
Direct heating system. Heating system which generates heat from electrical energy and dissipates it to the room to be heated with a response time being as low as possible.
A mechanical switching device which, in the open position, complies with the rcquirements specified for the isolating function. NOTE 1: A disconnector is otherwise known as an isolator. NOTE 2: A disconaecto. Distribution board. An assembly containing switching or protective devices e. It may also include signalling and other control devices. Means ofisolation may be included in the board or may be provided separately. Distribution circuit.
A circuit supplying a distribution board or switchgear. A distribution circuit may also connect the origin of an installation to an outlyirg building or separate installation, rr hen it is somelunes called a 'ub-rrain.
Double insulation. Insulation comprising both basic insulation and supplementaly insulatiofl. The conductive mass ofthe Earth, whose electric potential at any point is conventionally taken as zero. Earth electrode. Conductive paft, which may be embedded in the soil or in a specilic conductive medium, e. Parr of an earthing arangement comprising only the earth electodes and their intercol]uections. Earth fault current.
A currelt resulting from a fault of negligible impedance between a line conductor and an exposed-conductive-part or a protective conductor. Earth fault loop impedance. The impedance ofthe earth fault cuffent loop starting and ending at the point ofeanh fault. This impedance is denoted by the symbol I The earth fault loop comprises the lollowing, starting at the point offault: - the circuit protective conductor, alld - the consumer's earthilg teminal and eafihing conductor, and - for TN systems, the metallic rctum path, and - lor TT and lT systens, the Earth retum path, and - the path tkough the earthed neutml point ofthe transfonner, and - the tmnsfomier winding, and - the line conductor fi'om the transfomer to the point of fault.
Earthed concentric wiring. Awiring system in which one or more insulated conductors are completely surrounded throughout their length by a conductor, for example a metallic sheath, which acts as a PEN conductor'. Connection of the exposed-conductive-parts of an installation to the main earthing teminal of that installation.
Earthing conductor. A protective coflductor coulecting the main earthing terminal of an installation to an earth electrode ol to other means of eafihing. Electric shock. A dangerous physiologicaJ effect resulting from the passing ofan electric cufient through a human body or livestock. Electric vehicle EV , U Any vehicle propelled by an electric motor drawing curent from a rechargeable stomge battery or frour other portable energy storage devices rechargeable, using energy from a source off the vehicle ;uch as a residential or public electricity service , which is manufactured primarily for use on public streets, roads or highways.
Electric yehicle charging point. The point where the electric vehicle is connected to the fixed installation. Mode 1 charging. Mode 2 charging. Mode 3 charging. Connection of the EV to the AC supply network utilizing dedicated elect c vehicle supply equipment where the control pilot function extends to control equipment in the electric vehicle supply equipment, pen'r]anently connected to the AC supply netwolk.
Vehicle connector. Pafi ofa vehicle coupler integral with. Vehicle coupler. Means ofenabling the manual connection of a flexible cable to an EV for the purpose of charging. NOTE: A vehicle coupler consists of two pafts: a vehicle connector and a l'ehicle inlet. Electrical circuit for safety seryices. Electrical circuit intended to be used as part of an electrical supply system for safety services.
Electrical installation abbr: Installation. An assembly ol associated electrical equipment having co-ordinated charactedstics to fulfil specific purposes. Electrical source for safety services. Electrical source intended to be used as paft of an elect cal supply system for safety senrices.
Electrical supply system for safety services. A supply system intended to maintail the opemtion ofessentiaI pafis ofan elechical installation and equipment: i for the health and safety of persons and livestock, and ii to avoid damage to the environment and to other equipment. NOTE: The supply system includes the source and the circuit s up to the teminals ofthe elecl cal equipmcnt. Electrically independent earth electrodes. Eafih electrodes located at such a distance ftom one another that the maximum curaent likely to flow through one ofthem does not significanlly afl'ect the potential ofthe other s.
Electrode boiler or electrode water heater. Equipment for the electrical heatirg of water or electrolyte by the passage ofau electric cuflent between electrodes immersed in the water or electrolyte. Electronic convertor static convertor. A convertor having no movil. Ig parts and notably using semiconductol' rectifiers. Emergency switching.
An operation intended to remove, as quickly as possible, danger, which may have occumed unexpectedly. A part providing protection of equipment against ceflail extemal influences and in alty direction providing basic protection. Efficiency measures EM. Level of implementation of measrues to improve eoergy efficie[cy of an electical installation.
Load shedding. Approach where the elect cal loads are switched otf for variable periods of time to optimiTe demand. Equipotential bonding. Electrical connecrion maintainlng various exposed-conductive-pafis and ertraneous- colductive-pafts at substantially the same potential.
See also P7? Conductive part ofequiprrent which can be touched and which is not normally Jive. Any influence extemal to an electrical installation which affects the design and safe operation ofthat installation. Extralow voltage see Voltage, noninal. A conductive part liable to introduce a potential, generally Earth poteltial, and not lorrning part ofthe eiectrical insrallation.
Area where one or more stands, amusement devices or booths are erected for leisure use. A circuit condition in which current flows through an abnormal or unintended path. This may result frorr an insulation failure or a bridging ofinsulation.
NOTE: Conventionally. Fault protection. Protection against electric shock uuder single fault conditions. NOTE: For low voltage installations, systems and equipment, fault protection generally corresponds to protectiol against inditect contact, mainly with regard to failure ofbasic insulation.
Final circuit. A circrtit connected directly to current-using equipment, or to a socket-outlet or socket-outlets or other outlet points for the connection ofsuch equipment. Fixed equipment. Equipment designed to be fastened to a support or otherwise secured in a specific location. Flexible cable. A cahle whose structure and materials make it suitable to be flexed while in service. Flexible sheet heating element.
Heating element consisting of sheets of electrical insulation laminated with electrical resistance material, or a base material on which electrically insulated heating wires are fixed. Flexible wiring system. A wiring system designed to provide mechanical flexibility in use without degradation of the electrical components. Functional earth. Earthing ofa point or points in a system or in an installation or in equipment, lor putposes other than electrical safety, such as for proper functioning ofelectrical equipment.
Functional extra-low volfage FELV. Functional switching. An operation intended to switch 'on'or 'off'or vary the supply ofelectdcal energy to all or paft ofan installation for normal operating purposes. A device which, by the melting ofone or more ofits specially designed and proportioned components, opens the circuit in which it is insefied by breaking the curent when this exceeds a given yalue for a sufficient time.
The fuse comprises all the pafis that lorm the complete device. Fuse element. A parl ofa fuse designed to melt when the fuse operates. Fuse link. A pafi of a fuse, including the fuse element s , which requires replacement by a rew or renewable fuse link after the fuse has operated and before the fuse is put back into service.
Fused connection unit. A device associated with the fixed wiring of an installation by which appliances tray be connected, and having provision for a replaceable cartridge fuse link. Gas installation pipe.
Auy pipe, not being a sewice pipe other than any part of a sewice pipe comprised in a p mary meter installation or a pipe comprised in a gas appliance, for conveying gas for a particular consumer and including any associated yalve or other gas fitting. Harmonized Standard. A standard which has been drawn up by common agreemenr between national standards bodies notified to the European Commission by all member states and published under national procedues.
A Jive part which can give, under cefiain conditions of extemal influence, an electric shock. Heating cable. Cable with or without a shield or a metallic sheath, intended to give offheat for heating purposes. Heating-free area.
Unheated floor or ceiling area which is completely covered when placing pieces of flrrniture or kept free for built-in furniture. Heating unit. Heating cable or flexible sheet heating element with rigidly fixed cold tails or teminal fittings which are connected to the terminals ofthe electrical installation. High-density livestock rearing. Breeding and rearing of livestock for which the use of automatic systems for life support is necessary NOTE: Examples ofautomatic life support systems are those for ventilation, feeding ard air conditioning.
A highway means any way other than a waterway over which there is public passage and includes the highway verge and any bridge over which, or tunnel through which, the highway passes. Highway distribution board. Afixed shucture orunderground chamber, located on a highway, used as a distribution point, for connecting more than one highway distribution circuit to a common odgin. Street fumiture which supplies more than one circuit is defined as a highway distribution board.
The connection of a single temporary load to an item of street fumitue shall not in itself make that item of street fumitwe into a highway distlibution board. Highway distribution circuit. A Band ll circuit connecting the origin of the installation to a remote highway distribution board or items ofstreet fumiture. It may also connect a highway distribution board to street fumiture.
Highway power supply. An electdcal installation comprising an assembly of associated highway distribution circuits, highway distribution boards and street fumitule, supplied from a commol origin. Floating decked structue which is designed or adapted for use as a place of permanent residence often kept in one place on inland water. Aparameter used for the classification test for SPDs; it is defined by tfuee elements, a cu-rent peak value, a charge Q and a specific energy WR.
The highest peak value of impulse voltage of prescribed fotm and poladty which does not cause breakdown ofinsulation under specified conditions. Indirect contact see Faull protection. Examination ofan electrical installation using all the senses as appropriate. Installation see Electrical installation. Instructed person electricallD. Suitable non-conductive material enclosing, surounding or supporting a conductor. The selection of the electric strength of equipment in relation to the voltages which can appear on the system for which the equipment is intended, taking into account the service environment and the charactedstics ofthe available protective devices.
Function intended to make dead for reasons ofsafety all or a discrete section ofthe electrical installation I. A mechanical switching device which, in the open position, complies with the requirernents specified for ihe isolating function. An isolator is otherwise known as a disconnector. Leakage current. Electdc current in an unwanted conductive path under nomal operating conditions. Leisure accommodation vehicle. Unit of living accommodation for temporary or seasonal occupation which may meet requirements for construction and use ofroad vehicles.
Zone where the lightning electromagnetic environment is defined. Line conductor. A conductor of al j. LiYe conductor see Lite Part ' use' including a neutal conductor but' pafi intended to be energized in normal Live part. Low voltage lsee Voltage, nontinal ' devices or more low voltage switching assemblll Combinal'. TheterminalorbarprovidedfoJthe,connectionofprotectiveconductors,including of earthing' ;;;";; fJ; i'nctional earthing' if anv' to the means protective bonding conductors,.
Combinationofalltechrricalandadministrativeactions,includingsupervisionactions,intendedto can perfotm a required function. The replacement, refurbishment or cleaning of lamps Mechanical equipolent, Plant and machinery'. Pafiofmedicalelecfuicalequipmentthatinnomalusenecessarilycomesintophysicalcontact ul with the patient for ot un Mf syst"m to petfom its function' "ffit"'t discontinuity failure applied pafis are irtended to be used and where.
Group 0. Medical location where no ofthe supply cannot cause danger to life' threat to the safety failure ofthe supply does not represent a.
Group 1. Medical locarion where applied such as: ;. NOTE: The svsten, includes those accesso es which are needed for operating the system and are specified by the manufacturer. IT electrical system fi. NOTE: These supplies are also known as isolated power supply systems. Living being person or animal undergoing a medical, surgical or dental procedure. NOTE: A person under treatment lor cosmetic purposes may be considered a patient.
Patient enyironment. Any volume in which intentional or unintentional contact can occur between a patient ar]d pafis of the medical electrical equipment or medical elechical system or between a patient and other persons touching pal1s ofthe medical electrical equipment or medical electrical system. NOTE 2: This applies when the patient's position is predetennined; ifnot, all possible patient positions should be consideled. Illuminance lor emergency lighting at the end of the rated opemting time Minor works.
Additions and alterations to an installation that do not extend to the provision ofa new circuit. NOTE: Examples include the addition ofsocket-outlets or lighting points to an existing circuit, the relocation ofa light switch etc. Mobile and offshore installations. Installations used for the exploration or development of liquid or gaseous hydrocarbon resources.
Mobile equipment portable equipment deprecated. Electrical equipment which is moved while in operation or which can easily be moved ftom otre place to another while connected to the supply. Mobile home. A transportable leisure accommodation vehicle which includes means for mobility but does not meet the requirements for construction and use ofroad vehicles.
Motor caravan. Self-propelled leisure accommodation vehicle, used for toudng, that meets the requiremenls for the constluction and use ofroad vehicles. NOTE: It is either adapted from a series production vehicle, or designed and built on an existing chassis, with or without the driving cab, the accommodation being either fixed or dismountable. Neutral conductor.
A conductor connected to the neutral point of a system and contributing to the transmission of electrical energy. The term also means the equivalent conductor of an IT or DC system unless otherwise specified in the Regulations and also identilies either the mid-wire ol a three-wire DC circuit or the earthed conductor of a two-wire earthed DC circuit.
Nominal discharge current In. Nominal yoltage see Voltage, noninal. A non-conformity that may give rise to danger. Non-flame propagating. Liable to ignite as a result of an applied flame but, after the flame is rertoved, does not propagate flifiher and extinguishes itself within a limited time. A part preventing unintentional contact with live pafis but not preventing deliberate contact.
Open-circuit voltage under standard test conditions Uo" src. Voltage under standard test conditions across an unloaded open generator or on the DC side ofthe convertor.
Gangway providing access to facilitate operations such as switching, controlling, setting, observation and maintenance of electdcal equipment. The position at which electrical energy is delivered to an electrical installation' origin of an installation.
Pointonthepermanentinstallationolothelsoulceofsupplyfrom whifh electrical energy is delivered to the tempomry electrical installation the lated value is the curent-carying capaciry oyercurrent. A curent exceeding the mted value. AmethodofestablishingthattheValueofcurrentinacircuitexceedsapredetermined value for a specifled length of time. Device provided to interrupt cunent in the electric circuit exceeds a predetermined value for a specified duration'.
An overcunent occuring in a circuit which is electrically sound. Selectivityuptoagivenovelcurentlowelthanthebleakingcapacityofthedownstrcamdevice' PEL. Aconductorcombiningthetirnctionsofbothaplotectiveearthingconductolandalineconductol' which is not electrically sepamted from Earth' PELV protectiye extra-low yoltage.
An extra-low voltage system but which otherwise satisfies all the requirements for SELV. Aconductorcombiningthefunctionsofbothaprotectiveearthingconductorandamidpointconductor protective conductor and neutral conductor' PEN conductor.
A conductor combining the functions ofboth. Any boat, vessel, yacht, motor launch, houseboat or leisure. Accessory having pins designed to engage with the contacts-of the Electrical connection and mechanical retention of a flexible cable'.
A temination ofthe fixed wifirg intended fol the connection ofcurent-using equipment. Portable equipment see Mobile equipment powertrack. A system component, which is generally a linear assembly ofspaced and supported busbars, ploviding electrical connection olaccessories'. Powertracksystem PTsystem. Protectiveconductor PE. Aconductorusedforsomemeasulesofplotectionagainstelecfficshockandintended fo1 connecting together any ofthe following palls:.
Protective equipotential bonding. Equipotential bonding for the pulposes of safety. Protectiye multiple earthing PME. An eafthing arangement, found in TN-c-s systems, in which the supply r3utral conductor is used to corulect the eafihing conductor of an installation with Eafth, in accordance with the :. Protective separation. Separation olone electric circuit from another by means ol ti double insulation. Mechanically and electrically integrated assembly ofPV modules, and other necessary components, to :.
Basic PV device which can generate electricity when exposed to light such as solar radiation. PY convertor. Enclosure wherc PV arrays are electrically connected and where devices can be located. Erected equipment ofa PV power supply system.
PV module, Smallest completely environmentally protected assembly of interconnected pV cells. Circuit in which PV modules are connected in series, in order for a PV anay to generate the required output yoltage.
Cable connecting the AC tenninals of the PV convertor to a distribution circuit of the electrical installation. Rated current. Value of curent used for specification purposes, established for a specified set of operating.
Rated impulse withstand voltage level U,,. The level of impulse withstand voltage assigned by the manufacturer to the equipment, or to part of it, characterizing the specified withstand capability of its insulation against overuoltages. Reduced low voltage system. A system in which the nominal line-toline voltage does not exceed volts and the nominal line to Earth voltage does not exceed Reinforced insulation.
Single insulation applied to live parls, which provides a degree ofprotection against electdc shock equivalent to double insulation under the conditions specified in the relevant standard. The term 'single insulation'does not imply that the insulation must be one homogeneous piece.
Communicating the results ofperiodic inspection and testing of an electrical installation to the pe6on ordering the work. Residences and orher iocations which have a conductive connection to the agricultural and horticulturai premises by either protecrir e conduclols of the same installation or by extraneous-conductive-parts. NOTE: Examples ofother locations include offices, social rooms, machine halls, u,orkrooms.
Residential park home. Residual current. Algebraic sum of the cuffents in the live conductors of a circuit at a point in the electical installation.
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