What is the starting current for star delta starter?

What is the starting current for star delta starter?

Motor Starting Characteristics of Star-Delta Starter Available starting current: 33% Full Load Current. Peak starting current: 1.3 to 2.6 Full Load Current.

How do you calculate star delta current?

Motor Full Load Current (Line) = (10×0.746)x1000/1.732×415=13 Amp. Motor Full Load Current (Phase) =Motor Full Load Current (Line)/1.732. Motor Full Load Current (Phase) ==13/1.732=7 Amp. Motor Starting Current (Star-Delta Starter) =3xFull Load Current.

Does the star delta starter increases the starting current?

A star delta starter is a type of reduced voltage starter. We use it to reduce the starting current of the motor without using any external device or apparatus.

What is the time for Star to Delta?

In star Delta usually we consider that the load and motor torque are equal when the motor reach 75-85% of the speed. At this time you stop the star connection to go with delta connection, the time is around 30 to 50 milliseconds, to avoid short-circuit.

Why motor starting current is high?

At start, the reactance of the rotor is high because the slip of the motor is equal to unity. The value of Rr/s increase as the slip gets decrease. When the induction motor is started the rotor reactance is more than the rotor resistance and because of the large Xr/Rr ratio the motor takes large inductive current.

What is line current and phase current in star delta starter?

As the voltage across the winding is reduced by 1 / √3 times, the current flowing in each winding is also reduced by the same amount. Hence, the phase current or the current through winding becomes IP = I / √3. Since the Line current and phase current in star connection are equal, the Line current IL = I / √3.

How do you calculate phase current?

Three Phase Current – Calculation

1. kW = kVA x pf.
2. kVA = kW/pf.
3. kVA = kW / power factor = 23/0.86 = 26.7 kVA (26700VA)
4. Current = VA / voltage = 26700 / 230 = 116 A.
5. VLL =√3 x VLN
6. VLN = VLL / √3.
7. kVA = kW / power factor = 12 / 0.86 = 13.9 kVA (13900 VA)
8. Current = VA / voltage = 13900 / 230 = 60 A.

Why the starting current of induction motor is high?

This high current in the rotor will create its own magnetic field which opposes the main stator magnetic field, this weakens the stator magnetic field so the back EMF in the stator will drop and the supply voltage will be much higher than the stator back EMF and so the supply current increases to a high value.

How does star connection calculate line current?

We know in the star connection, line current is same as phase current. The magnitude of this current is same in all three phases and say it is IL. ∴ IR = IY = IB = IL, Where, IR is line current of R phase, IY is line current of Y phase and IB is line current of B phase.

What is star Delta changeover?

The star-delta open transition model is very similar to that of the direct-on-line starter. The additional elements are: a star contact to set the motor winding initially in start configuration, as switched out after the time given by Ts.