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The conductors that connect a three-phase supply to its load are called 'line conductors' or, more simply, 'lines'. The individual generator stator windings, transformer winding, or loads are called 'phases'.
Lines and line terminals are identified by colours, letters, numbers, or combinations of letters and numbers. For example, A-B-C. Phases are identified by using the letters assigned to the line terminals between which the phases are connected, e.g A-B, B-C, and C-A.
Voltages measured between lines ('line-to-line') are termed 'line voltages', and currents that pass through the lines are called 'line currents'.
Voltages measured across a generator's windings, transformer windings, or individual loads, are called 'phase voltages', and the currents that pass through these are called 'phase currents'.
For a three-phase, three-wire, system, the phase- and line-voltages are numerically-equal to each other. For a three-phase, four-wire, system, the line voltage is 1.732 times larger than the phase voltage.
Wiki User
∙ 9y ago
Wiki User
∙ 9y agoFor a three-phase, three-wire, system, the line voltage and the phase voltage are numerically equal to each other, and both are measured between any pair of line conductors.
For a three-phase, four-wire, system, the line voltage is 1.732 times the phase voltage. The line voltage is measured between any pair of line conductors, whereas the phase voltage is measured between any line conductor and the neutral conductor.
Wiki User
∙ 11y agoThe three 'hot' conductors supplying a three-phase system are called 'line conductors'. A line voltage is the voltage between any pair of line conductors.
In a 'delta' connected system, phases are the loads connected between the three line conductors. So, for a delta-connected load, the phase voltages correspond to the line voltages.
In a 'star' or 'wye' connected system, phases are the loads connected between the line conductors and a neutral conductor. So for a star-connected system, the phase voltages exist between any line conductor and the neutral conductor, and equate to 0.577 x the value of a line voltage (or, if you prefer, a line voltage is 1.732 x a phase voltage).
To summarise, for delta connected systems, a line voltage is measured between line conductors, and a phase voltage is numerically equal to that line voltage. For star-connected systems, line voltages exist between line conductors, whereas phase voltages exist between any line conductor and a neutral conductor.
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∙ 9y agoIn a delta connection, the line voltage is equal to the phase voltage. In a star connection, the line voltage is 1.732 larger than the phase voltage.
Wiki User
∙ 12y agoline voltage is 1.732 times of phase voltage
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What is the voltage phase shift between primary and secondary line voltages in star-delta transformer connection?
The voltage phase shift between primary and secondary connections in a transformer is 180 electrical degrees.
What is the mean of 220-440 connection of 3 phase motor?
Star 220 v and delta 400 i star 58 percent only voltage applied delta 400v appliedAnswerThese figures do not represent three-phase, four-wire, system voltages, because if the line voltage were to be 440 V, then the phase voltage would be 254 V; or, if the phase voltage were to be 220 V, then the line voltage would be 381 V.
Where the volatage is measured in the three phase systems?
You can use wattmeters to measure three-phase power. According to 'Blondel's Theorem', you can use one less wattmeter than there are conductors connecting the load to the supply. So, for a three-wire system, you can use two wattmeters but for a four-wire system, you must use three. Check out 'three wattmeter method' and 'two wattmeter method' on the internet to find the necessary connection diagrams.
Star-star connection of transformer?
Star Star TransformerStar Star Transformer is formed in a 3 phase transformer by connecting one terminal of each phase of individual side, together. The common terminal is indicated by suffix 1 in the figure below. If terminal with suffix 1 in both primary and secondary are used as common terminal, voltages of primary and secondary are in same phase. That is why this connection is called zero degree connection or 0o - connection.If the terminals with suffix 1 is connected together in HV side as common point and the terminals with suffix 2 in LV side are connected together as common point, the voltages in primary and secondary will be in opposite phase. Hence, Star Star Transformer connection is called 180o - Connection, of three phase transformer.Vikram Meena
Why is it stated - 3 phase 440 VAC when one phase voltage is 220 VAC?
In three-phase there are three live wires and a neutral. The voltage of a three-phase system is always quoted as the live-to-live voltage, and the voltage from one live wire to neutral is 57.7% of that. A 440 v 3-ph system has 254 volts between live and neutral. <<>> The question statement is not correct. Two legs from a three phase three wire 440 volt system will still be 440 but classed a single phase. On a three phase four wire system supply, the voltages will be determined by the following equation. 440/(square root of 3) 1.73 = 254 volts. The second single phase voltage attainable from this source connection is any one of the three phase legs to grounded neutral center point. This is known as a wye or star point connected voltage supply. To obtain a 220 volt single phase voltage, the three phase system would have to have a voltage of 220 x 1.73 = 380 volts.
Why in a star connection phase voltage is 1.73times of line voltage?
It isn't. It's the other way around. The line voltage is 1.732 times the phase voltage. The figure results when you vectorially add the relevant phase voltages.
What is line voltage in star connection?
Phase to phase voltage is 1.732 (the square root of 3) times the phase to star point (neutral) line voltage.e.g. if the line voltage is 220Vphase voltage = 1.732x220 = 380V (approx)Additional AnswerYou might also like to know that the line voltage leads the phase voltage by 30 electrical degrees. And, incidentally, the correct expressions are 'line-to-line' not 'phase-to-phase', and 'line-to-neutral' not 'phase-to-neutral' (think about it, a line voltage is measured from the junctions between adjacent phases, so they cannot be 'phase to phase'!)
What is the connection of normal wire star or delta?
normally delta connection wired in 3 phase induction motor. during starting wiring is in Star and after running normal speed changeover to delta .beacause starting time its phase voltage equals less root3 times of line voltage ,line current and phase current equals. in Delta phase voltage and line voltage equals, and phase current equals root3 times line current
How is the neutral point in a star connection created?
In a distribution transformer's star-connected secondary, the common point of connection is called the 'star point' and is connected to earth. The star point then provides the neutral connection for the transformer secondary, providing a return path for any unbalanced currents due to an unbalanced three-phase load.This arrangement provides a four-wire distribution system, comprising three line conductors and one neutral conductor (in addition, there are various methods of providing an earth connection to consumers). The line-to-line voltage is called a line voltage (in the UK, 400 V), while a line-to-neutral voltage is called a phase voltage (in the UK, 230 V). The line voltage being 1.732 x phase voltage.
What is the voltage phase shift between primary and secondary line voltages in star-delta transformer connection?
The voltage phase shift between primary and secondary connections in a transformer is 180 electrical degrees.
What is the mean of 220-440 connection of 3 phase motor?
Star 220 v and delta 400 i star 58 percent only voltage applied delta 400v appliedAnswerThese figures do not represent three-phase, four-wire, system voltages, because if the line voltage were to be 440 V, then the phase voltage would be 254 V; or, if the phase voltage were to be 220 V, then the line voltage would be 381 V.
Why is star connection used in a three phase transformer?
The power of all three phases can be transmitted on three conductors.A star connection, as opposed to a delta, provides a grounding reference. Also, for ground faults on the secondary (assuming no delta third winding, or source third winding) will be a direct ratio similar to phase faults, instead of 57%. Another reason is to avoid the inherent phase shift involved in a delta/star configured transformer.Another AnswerA 'star-connected' secondary is the standard European connection for a three-phase distribution transformer, as it provides a line voltage of 400 V together with a phase voltage (i.e. line to neutral) of 230 V.
How can three types of supply be obtained from the secondary side of a delta star transformer where the supply voltage is 11000 V?
The standard three-phase distribution transformer in the UK is a delta/star connection with a rated primary line voltage of 11 kV, and a nominal secondary line voltage of 400 V, giving a secondary phase voltage of 230 V.So, the secondary provides a three-phase, four-wire, system comprising three line conductors and a neutral conductor. The line-to-line (line voltage) voltage is 400 V and the line-to-neutral (phase voltage) voltage is 230 V.There are not 'three types' of supply obtained from this arrangement.
What is 1.73 in load current calculation?
1.73 (the square-root of 3) is the ratio of line voltage to phase voltage in a star (wye) three-phase connection, and is the ratio of line to phase current ratio in a delta three-phase connection supplying a balanced load. In each case, it is derived from the phasor addition of two values displaced from each other by 120 electrical degrees.
What is the kv phase to phase for 13.8kv?
There is no such thing as a 'phase-to-phase' voltage; the correct term is 'line-to-line' voltage. Whenever you mention a value of voltage for a three phase system, it is considered to be a line-to-line voltage unless it is stated clearly that this is phase voltage (line to neutral) voltage.(The reason that there is no such thing as a 'phase-to-phase' voltage is because phases exist between, or 'across', line conductors or between a line conductor and a neutral.) That is a world wide practice for electrical power engineers.
What is star connection in datail?
If you can imagine a machine's three phase windings with a common point of connection, thus forming a 'star' shape, with each phase winding displaced from each by 120 degrees. The 'free' ends of the three phase windings are then connected, externally, by wires called 'line conductors', while the common point of connection (the 'star point') is (in the case of generators and transformer secondaries) earthed (grounded) and connected, externally, by a wire called the 'neutral conductor'.The voltages measured between any pair of line conductors are called 'line voltages', and the voltages measured between any single line conductor and the neutral conductor (i.e. across individual phase windings) are called 'phase voltages'. A line voltage is the vector sum of its phase voltages, making in 1.732 times the value of a phase voltage.
Why is three phase voltage 400 V when single phase is 230 single phase 1.73 3 phase. what is 1.73?
I will try and make this as simplified as possible. The secondary side of transfomers are connected in star - which means there is a neutral / earth connection. If you measure between a LINE to LINE ('line voltage') voltage you will measure 400V, but now we have introduced the neutral / earth and we measure between LINE to NEUTRAL ('phase voltage) 's LINE to EARTH we will get 230 V. The reason for this is that, because the phase voltages are displaced, in time, by 120 electrical degrees, you must add them vectorially to obtain the line voltage. And the vectorial sum of two 230-V phase voltages, displaced by 120 degrees, is 400 V -or 1.732 times either of the phase voltages.
