The Star-Delta control circuit diagram shows the delta contact and the main contact.
In motor starters, this is usually done using contactors. Explanation of this can easily be done using a circuit diagram. There are three contactors, the main, star and delta contactors-all these contactors can be the same type. There are many ways of wiring a star delta but here I will only give a generalized answer. First, the main contactor and star contactors are energised thus the motor runs in star. After about 5 seconds, the timer which gets energized at the same time as the main and star contactors, switches its CONTACTS i.e the normally open closes and the normally close opens. This dienergize the star contactor and energized the delta contactor. Thus, the motor now runs in delta.
Because it is the same current, as you can determine by examining a circuit diagram of a star connection.
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 link in the star contactor is used to form the star point of three of the motor leads. On most star wound motors the star point is inside the motor windings. On a motor that can be used for star delta starting it is a six wire motor. The star point winding depends on the contactor to tie the coil ends together externally in the control panel of the star delta starter.
Star voltage is 1 / 1.732, or 0.577 delta voltage. (1.732 is the square root of 3.) It follows, then, that star current is 0.577 delta current.Not asked, but answered for completeness, star power is 0.5772, or 0.3333 delta power. This is why large motors use a star-delta start sequence - to minimize startup thermal stress.
PLC logic is a digital computer used to automate electromechanical processes. The Star delta diagram is a diagram for a simple circuit that has the capabilities of starting a high horse power motor. A star delta diagram can be drawn in PLC Logic.
With a transformer...
With a transformer...
i don't know please help
12 lead out motor is generally with two different set of winding usually for double speed application. 6 lead connection is to enable star delta starter. With 12 lead the motor can be connected in star delta and for two speed application. It is better to explain with proper wiring diagram only so that no mistake is done.
There is many type of starter on three phase circuit but the most common are 1: D.O.L (Direct on line). 2: Manual Star Delta Starter. 3: Automatic Star Delta Starter.
Check your Delta connections first if the phases is corresponding, and check your Circuit Breaker if it sufficiently rated.
In motor starters, this is usually done using contactors. Explanation of this can easily be done using a circuit diagram. There are three contactors, the main, star and delta contactors-all these contactors can be the same type. There are many ways of wiring a star delta but here I will only give a generalized answer. First, the main contactor and star contactors are energised thus the motor runs in star. After about 5 seconds, the timer which gets energized at the same time as the main and star contactors, switches its CONTACTS i.e the normally open closes and the normally close opens. This dienergize the star contactor and energized the delta contactor. Thus, the motor now runs in delta.
The star delta motor starter circuit has to have a control voltage to energize the motor magnetic contractors. A phase failure relay monitors all three phases of the incoming supply lines. The phase failure relay also has auxiliary contacts on it. There are usually two sets of "C" form contacts. The control voltage for the starter circuit must be connected across the normally open (N.O.) contacts of one of these two sets. When the phase monitor is energized these N.O. contacts close supplying the control voltage to the circuitry of the star delta starters. If there is a phase interruption, phase reversal or phase loss, the phase failure relay will de-energize and the N.O. contacts will go back to their de-energized state. If the star delta motor starter is in use at the time, its control circuitry voltage will be lost and the delta motor magnetic contactor will open. The opening of this contactor will disconnect the motor from the failed three phase supply.
A lot of designers will fit an under rated star contactor, partly for cost saving purposes and partly down to the fact that the star contactor will only stay energised for a brief period. Burning out the star contactor could be down to it staying in circuit too long, not changing over to delta, a timer malfunction holding in the star contactor or switch that is defective in the control circuit. Another cause could be your motor is drawing excess current.
please you give me reply to answer.
On a star delta starter a motor overload or a motor going to ground and cause a short circuit will cause the overload protection to trip. These overloads have to be reset before the motor can be restarted.