Short circuit - definition of short circuit by The Free Dictionary (. You look nice with your hair short; Do you think my dress is too short? When I checked my change, I found it was 2. Most of us are short of money these days. He stopped short when he saw me. The dress is too long . He will be here shortly; Shortly after that, the police arrived. We've short- listed three of the twenty applicants. I don't recognize people at a distance because I'm short- sighted. My husband is very short- tempered in the mornings. His name is Victor, but we call him Vic for short. Save this carton for tomorrow, or else we'll go short (of milk). Fresh vegetables are in short supply. The children made short work of the ice- cream. Our money is running short. We're running short of money. Our total came to just short of $1,0. We stopped five miles short of London. Electrical wiring in the United Kingdom. Electric wiring in the United Kingdom is commonly distinguished by a number of criteria, such as voltage (low, very low, high, etc.), phase (single or 3 phase), nature of electrical signal (power, data), type and design of cable (conductors and insulators used, cable design, solid/fixed or stranded/flexible, intended use, protective materials), circuit design (ring, radial), and so on. Most electrical wiring is ultimately regulated for legal purposes, by the Building Regulations, currently legislated as the Building Regulations 2. The detailed rules for end- use wiring followed for practical purposes are those of BS 7. Requirements for Electrical Installations. IET Wiring Regulations, informally, the regs), currently in its 1. Amendment 3, which provide the detailed descriptions referred to by legislation. UK electrical wiring is largely harmonised with the regulations in other European countries and the international IEC 6. These include the use of ring circuits for domestic and light commercial fixed wiring, fused plugs, and for circuits installed prior to harmonisation, historically unique wiring colours. Common terminology. Distribution board (DB)Panel that splits power from one main source into separate circuits, each with independent protection. Breakers and safety devices. SHORT CIRCUIT CAPABILITY OF GENERATOR CIRCUIT. The symmetrical short-circuit current. Short Circuit (1986) Trivia on IMDb. Quentin Tarantino Reveals He’s Researching 1970 For A New. The 3 Stooges short that #5 is watching is the end of. Cited Patent Filing date Publication date Applicant Title; US3493878 * Feb 3, 1967: Feb 3, 1970: Sperry Rand Corp: Self-resetting overload protection circuit for. INTERTURN SHORT-CIRCUIT DETECTOR FOR TURBINE-GENERATOR ROTOR WINDINGS D. Albright ABSTRACT An effective new method of detecting inter-turn. Mandatory for most circuits as of 1. Edition regulations. Residual current circuit breaker with overcurrent protection (RCBO)Combination of RCD and MCB; breaks circuit on being triggered either as an RCD or by overcurrent. Earth leakage circuit breaker (ELCB)An obsolete circuit breaker type triggered by electrical power in a fault wire connected only to specifically protected parts in the circuit and appliances (i. Wires and cables. Typically in a domestic environment, connects the electricity meter (which is owned by the power company and treated as the incoming source) to the consumer unit. Twin (2- ; and 3- or 4- ) core and earth. Rs t 5819 - 1970 Indian Standard RECOMMENDED SHORT-CIRCUIT RATINGS OF HIGH VOLTAGE PVC CABLES Conductors and Cables Sectional Committee, ETDC 32. Short-circuit currents in power lines and substations induce electromagnetic forces acting on the conductors. The forces generated by short-circuit. A method for measurement of short-circuit current and for applying a voltage clamp to segments of rat colon in vivo is described. The mucosa behaved as an ohmic. Flat cable, usually insulated by a PVC sheath, used for fixed wiring. The name comes from the fact that it contains line and neutral conductor cores with individual insulations (twinned), and an uninsulated earth core. Powerline. Multi- thread conductors that run between electric pylons, used for high voltage long distance power transmission. Voltage and phases. Almost all domestic and light commercial (e. High voltage. Any voltage in excess of low voltage; usually found in industrial processes and power transmission. Extra- low voltage (ELV)5. V AC or 1. 20 V ripple- free DC, or less. Separated extra- low voltage (SELV)Extra low voltage system that is also electrically isolated. Single phase, 3 phase. Power supplied as a difference between two conductors (single phase) or 3 conductors (3 phase). Domestic and light commercial wiring is almost always single phase 2. V, but industrial equipment is often 3 phase since this has advantages for equipment design and wiring efficiency. Earthing (bonding). Usually made from copper or copper- clad, galvanised, or stainless steel, for corrosion prevention. There are other types of earth bond, such as: earth plate, earth mesh, or earth ring. Circuit terminology. Loop wiring is radial wiring in lighting circuits where junctions are made at ceiling roses with line and switched line wires. Ring, or ring final circuit (RFC)A ring circuit is a UK standard means for wiring domestic and other light commercial premises, not often seen elsewhere in the world; in effect it is a radial circuit whose final termination is made back to the originating distribution board, rather than at the last outlet or device serviced. De- energized circuit. Circuit that is isolated from power and not at a potential different from earth. Note the difference to permit to work. Spur. A branch supplying a side- socket or outlet, especially from a ring circuit. Wiring colours. This colour scheme had already been introduced for appliance flexes in the UK in the early 1. IEE for fixed wiring was permitted until 2. As a result, the international standard blue/brown scheme is as of 2. In fixed wiring, the blue/brown scheme is only found in newer (post- 2. IEE black/red scheme is likely to be encountered in existing installations for many more decades. The standard colours in fixed wiring were harmonised in 2. European countries and the international IEC 6. For a transitional period (April 2. From April 2. 00. Potential for confusion. Blue, previously used as a phase colour, is now the colour for neutral. Black, which was previously used for neutral, now indicates a phase. Household wiring does not usually use three- phase supplies and the clash only occurs in three- phase systems. Wiring to the old standard can be detected by use of a red wire. The new standard colour code does not use red. Where new wiring is mixed with old, cables must be clearly marked to prevent interchange of phase and neutral. Variation in the earth/ground conductor's colour means its colour should not be used as the decision of the old vs new standard cable or colour assignment. Other colour schemes. This can occur on IEC mains leads and dual 2. V imported equipment. On telecommunications nominal 4. V DC supplies, the live is usually . These are: There is a long history of colour changes; prior to 1. World War II, a black earth and a green third phase in place of green earth and white phase was permitted. The regulations actually permitted (and still do) the use of any wire colour that is not an earth colour, providing it is unambiguously identified at all connections by clear labelling or by correctly coloured over- sleeving. Direct current mains supplies are now only of historical interest in the UK but the colour coding was red for live and black for earthed (regardless of the actual polarity). Hardly any loads were polarity sensitive when D. C. In later years of D. C. Where all three wires were available, the historical colour code was red (positive), black (middle) and white (negative). The negative line changed to yellow in 1. Sheath colours. Previously cables from different manufacturers were available variously in grey or white, with no significance attached to the sheath colour. Circuit design. Lighting circuits, which typically have lower power requirements, are usually radially wired, confusingly sometimes called . The difference is that a radial circuit simply ends upon reaching the last connected device, while in a ring circuit the termination is made by rejoining the end of the circuit from the last device back to its starting point. A ring circuit therefore forms a continuous ring. This means that there are two independent paths from the supply to every device. Ideally, the ring acts like two radial circuits proceeding in opposite directions around the ring, the dividing point between them dependent on the distribution of load in the ring. If the load is evenly split across the two directions, the current in each direction is half of the total, allowing the use of wire with half the current- carrying capacity. In practice, the load does not always split evenly, so thicker wire is used. Cables are most commonly a single outer sheath containing separately- insulated line and neutral wires, and a non- insulated protective earth to which sleeving is added when exposed. Standard sizes have a conductor cross sectional area of 1, 1. Sizes of 1 or 1. 5 mm. The earthing conductor is uninsulated since it is not intended to have any voltage difference to surrounding earthed articles. Additionally, if the insulation of a line or neutral wire becomes damaged, then the wire is more likely to earth itself on the bare earth conductor and in doing so either trip the RCD or burn the fuse out by drawing too much current. Earthing and bonding. Earthing therefore provides a return path for the current required to blow fuses or trip circuit breakers and RCDs, and ensures that the supply is reliably disconnected in the event of a fault. Bonding is the connection of the exposed conductive part of electrical equipment or objects like mains water / gas supply pipe to the main Earth terminal (MET) to bring all exposed metalwork into the same electrical potential. This is done to minimise the danger of electric shock due to human contact with live parts which could result from bad insulation and insulation failures. Bonding wires are typically thicker than earthing wires to ensure that they have a sufficiently low resistance that hazardous voltages (as calculated by V=IR) cannot appear even in the presence of large fault currents. In domestic wiring, earthing of equipment is done by bonding together the earth points and metallic parts of the appliances and earthed bodies using green/yellow wire coming from the consumer main earthing terminal. The earth terminal is in turn connected to either consumer. In pre- 1. 96. 6 buildings, the earthing may be connected only to the plumbing system, which is creating potential earthing problems in buildings where the metal pipes are being replaced by non- conductive plastic pipes. The exception is within a transformer for use in a bathroom for shavers which has no earth. This is because the shaver socket is electrically separated from the mains supply via the use of an isolating transformer, with the output of the shaver socket being connected to the secondary side of the isolating transformer, to receive a shock, both conductors would have to be grasped simultaneously, touching earthed metalwork would have no effect as there is no path to complete the circuit. A three phase supply may be either delta connected or star connected due to the physics of three phase supply. Power stations always supply in three phase for physical reasons, not least costs and others not dealt with here. Delta and Star are as one would draw the figures on a piece of paper. The sketch would be joining three dots each equally set in space as a set. Star has a natural central neutral which may or may not be connected as appropriate by the authorities.
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