With a delta connection, picture a triangle. Each side of the triangle is a transformer or motor winding. Call the 3 corners of the triangle A, B, and C. There are only 3 wires except for a safety ground, which has no connection to, nor is any part of, the power transmission service lines.but for the star connection take our triangle above and use your wire cutters (literally) to cut the triangle apart at the corners. rearrange the three sides (transformer or motor windings) to form a Y. Where the three sides join in the centre, connect a fourth wire. Call this wire "neutral". Call the three ends A, B, and C. Connect the 3 supply service lines to A, B, and C.
A wye connection contains three phases that are tied together with a neutral connection. A delta contains three phases that are tied together but needs no neutral wire as each of them surves as a return path to complete the circuit back to the generator!
There is no difference. A three-phase 'star' connection is simply another name for a 'wye' connection. 'Star' seems to be the preferred name in Britain, whereas, 'wye' seems to be the preferred name in North America -although this is debatable.
Out of interest, the alternative name for for a 'delta' winding is a 'mesh' winding.
A star or (wye) winding is a three phase four wire system. Three "hot legs" and a common neutral wire that connects all three phase coils together at one point where it is grounded to the system ground. The voltage is taken from the other end of the phase coils. In addition a square root of 3 (1.73) voltage can be taken from each coil end and the grounded neutral. Phase voltage divided by 1.73 equals line to neutral voltage.
A delta winding is a three phase three wire system. All three phase coils are connected together end to end. The system voltage is measured from each one of these connection points.
"star" type transformer windings are used when a neutral is needed. "Delta" windings are for applications where a neutral is not usually required.
A wye connection or a star connection has three or more phases connected to a single point which is also known as neutral point where as the other ends are connected to voltages phase shifted from each other according to the number of phases. Hence in a wye connection we always get a phase connection across the load. Delta on the other hand has both ends of the load connected to the next phase. There is no neutral point and the current at a time enters through one phase and goes out through the other . Hence we always get the line voltages across the load.
In delta-wye there is a neutral on the secondary side. In delta-delta there is no neutral.
There is no difference. 'Star' and 'wye' are alternative names for the same connection. Similarly, 'delta' and 'mesh' are alternative names for the same connection.
It is not true that another name for the "Y" or "wye-connected" system of polyphase power is the "delta" system. It's called the "star" system.
An open delta connection is a delta connection with one phase removed, but still supplied with three line conductors. An open wye is a wye connection with one phase removed, supplying a three line conductors and a neutral conductor. An open-delta/open-wye is a method of providing a reduced-load three-phase supply using just two single-phase transformers, rather than the preferred method of using three single-phase transformers.
For the same load, delta provides higher current than wye, or star.Wye voltage is 1 / 1.732, or 0.577 that of delta. (1.732 is the square root of 3.) This gives a power of 0.333 for wye, as opposed to delta. (0.5772 = 0.333)This is why (no pun intended) we use wye-delta starters on large motors - it allows them to come up to speed at 1/3 power, before switching to full power on delta.
the speed decrease if increasing load..in star connection the speed lower
To terminate a 3 wire wye motor to a 3 phase delta connection you need a 3 phase transformer to convert from delta to wye. Do not lift the common neutral connections inside the motor and rewire for delta, because the voltages will be wrong.
A star-delta motor should be supplied star-delta.Wye is simply another name for star. Star-delta motors use a star or wye configuration to start, and a delta configuration to run. This reduces the voltage on the windings during the high current starting time.
The power of a three-phase load is the sum of the three individual loads. It makes no difference whether they are connected in star (wye) or in delta.
It is not true that another name for the "Y" or "wye-connected" system of polyphase power is the "delta" system. It's called the "star" system.
An open delta connection is a delta connection with one phase removed, but still supplied with three line conductors. An open wye is a wye connection with one phase removed, supplying a three line conductors and a neutral conductor. An open-delta/open-wye is a method of providing a reduced-load three-phase supply using just two single-phase transformers, rather than the preferred method of using three single-phase transformers.
For the same load, delta provides higher current than wye, or star.Wye voltage is 1 / 1.732, or 0.577 that of delta. (1.732 is the square root of 3.) This gives a power of 0.333 for wye, as opposed to delta. (0.5772 = 0.333)This is why (no pun intended) we use wye-delta starters on large motors - it allows them to come up to speed at 1/3 power, before switching to full power on delta.
A delta starter supplies what ever the supplied voltage to the line side of the contactor is. The inrush current is usually 300% of the full load amperage of the motor. Edit to above answer: Actually the question is for a Wye-Delta Starter (Wye=Star). There are two contactors, one in Wye configuration and one with Delta. The Wye is used to start and the Delta for run. This is a reduced voltage start scheme. Though the line supply voltage remains the same, for instance 480VAC, the phase voltage at the motor will be different for the Wye: V(phase) = V(line)/1.732 In a Delta V(phase) = V(line) So the Phase Voltage during the start will be 277VAC and then when the motor is spinning, usually after a set time delay, the Wye contactor drops out and the Delta contactor kicks in so that Phase Voltage is now the full 480VAC.
the speed decrease if increasing load..in star connection the speed lower
Postcode for Kidderminster in the West Midlands, UK. Also a vector group (connection configuration) of a 3-phase transformer.D - Means Delta Wound Primary Y - Means Wye (Star) Wound Secondary 11 - Is the phase shift between the two windings. The 11 refers to 11 on a clock face, hence 30 degrees.
in low voltage connection in wye (star conncetion) 415v high voltage connection in delta 480v
To terminate a 3 wire wye motor to a 3 phase delta connection you need a 3 phase transformer to convert from delta to wye. Do not lift the common neutral connections inside the motor and rewire for delta, because the voltages will be wrong.
It won't. Star and Delta deliver the exact same power. The only difference is Star (also called wye) configurations contain a neutral and allow single-phase, ground referenced loads to be fed. also star wiring draws less current when the motor starts up, but is less efficient when motor is at running speed so it is then switched over in to delta mode as that draws less current in runing mode
wye delta diagram