In a high voltage installation, with the same power, current drawn is small compared to those in low voltage. However it requires a thicker insulation, thus cost of insulation is significant compared to the conductor cost.
By using a star connected winding, the insulation voltage required is equal to line to neutral connection, otherwise if it is connected in delta the insulation rating has to be provided for a line to line connection.
Despite having a higher current, the total cost is still lower compared to using a higher insulation rating.
Wye vs. Delta connections are site specific. I often see high voltage sides of Transformers connected in delta - specifically distribution level step down transformers are very often Delta/Wye. A wye connection provides a ground connection, so connected conductors only need be insulated for L-N voltages (if solidly grounded), instead of L-L voltages for a typical delta connection. There are other reasons that come into play as well.
Gently we are using star delta starter for hiegh rating motors,,in star connection the line current is equal to the phase current and incase delta connection the line and phase voltages are equal,,at starting the current will be maximum.
hot motor are connected in star because it deals with the voltage in case small Power system, which the voltz could either drop or rise.
becoz if we connect it in delta,it draws much current,,,,so we connect in star to draw less current
If a motor is connected in a star configuration it will operate at a slower speed. This is the working process that a star delta starter operates on. At first through the starter the motor starts in the star connection. When the motor gets up to its highest speed in that connection it times a timer out , the star starter drops out and the delta starter pulls in and then connects the motor in the delta connection. This allows more voltage to be applied to the motor and it then speeds up to its nameplate rated RPM.
A forward reverse star delta is a two in one motor starter where a motor first runs on star connection and then changed to delta connection after a time which has been set. The motor direction can be changed, whether forward or reverse
i think its use for 3 phase connection.
the speed decrease if increasing load..in star connection the speed lower
two contecter <<>> There are three contactors used in a Star Delta configuration.
In a large power motor the starting current is too high if connected 'direct on line'. If you start a motor on 'star' connection it uses less current to get it going before the 'delta' connection takes over.
If a motor is connected in a star configuration it will operate at a slower speed. This is the working process that a star delta starter operates on. At first through the starter the motor starts in the star connection. When the motor gets up to its highest speed in that connection it times a timer out , the star starter drops out and the delta starter pulls in and then connects the motor in the delta connection. This allows more voltage to be applied to the motor and it then speeds up to its nameplate rated RPM.
A forward reverse star delta is a two in one motor starter where a motor first runs on star connection and then changed to delta connection after a time which has been set. The motor direction can be changed, whether forward or reverse
i think its use for 3 phase connection.
the speed decrease if increasing load..in star connection the speed lower
Star and delta connection
There are both types of motors available in market.
when starting a 3 phase induction motor,first start with star connection,because reduced current is being applied and after start change it to delta connection then. full line current is applied to the motor.
two contecter <<>> There are three contactors used in a Star Delta configuration.
hot motor are connected in star because it deals with the voltage in case small Power system, which the voltz could either drop or rise.
star delta connection is used reduce high starting current of the motor. you can see the below diagram if you need anything more details... let me know
The inrush current is reduced. This is the reason for star delta starters. Motor starts on star and after about 10 to 15 seconds, depending on the load of the motor, it switches to a delta configuration to run.