It is a type of starter that allows a motor to be started across the line by starting the motor with a reduced inrush current. The motor is started in a wye configuration until it gets up to speed and then a timer drops the wye contactor out a draws the delta configured contactor in. The motor then operates in a delta wired configuration.
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.
There is really no advantage, the only purpose of having the variety is for motor manufacturer companies to be able to sell their product to customers if the building's electrical service is of a Delta of Wye configuration.
Motor run delta connection because in delta connection it is less ampere needed and it sometimes it change the wye connection because of the available suply
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.
It is a type of starter that allows a motor to be started across the line by starting the motor with a reduced inrush current. The motor is started in a wye configuration until it gets up to speed and then a timer drops the wye contactor out a draws the delta configured contactor in. The motor then operates in a delta wired configuration.
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.
There is really no advantage, the only purpose of having the variety is for motor manufacturer companies to be able to sell their product to customers if the building's electrical service is of a Delta of Wye configuration.
10 hp and above motor power rating....
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.
Motor run delta connection because in delta connection it is less ampere needed and it sometimes it change the wye connection because of the available suply
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.
Few things to look for, one, are the contacts good on the run contactors. Two, has the motor wiring been changed in any way, contactors or leads on motor. Trace wiring and make sure the leads are paired correctly to the starters. Three, make sure the start timer is not bringing the run contactors in too late. Also check that the shorting contactor is opening when the run contactor comes in.
in low voltage connection in wye (star conncetion) 415v high voltage connection in delta 480v
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.
in a delta configuration the current is split between the phases, as opposed to a wye configuration where the current will be equal on all phases. and vice versa for voltage.
the speed decrease if increasing load..in star connection the speed lower