Answer / jayant mistri

It is not correct that in DOL starter, motor starts in star connection. But motor starts with Line voltage i.e 415 volts P-P in our country. It is the motor which is connected in star or delta connection from terminal box or in the motor winding.If motor is connected in star connection,each winding (R,Y and B phase) of motor, get phase voltage i.e. 230 volts (motor gives less power i.e. motor power /1.73). and if motor is connected in delta connection,each winding (R,Y and B phase) of motor, get line voltage i.e. 415 volts.motor gives rated power.

In star delta starter, motor start in star and changes to delta connection after time delay. In star connection motor draws less current as each winding gets 230 volts and when it goes to delta connection each winding get line voltage. thus star/ delta starter starts motor in reduced voltage so that motor draw less starting current. This starting is called reduced voltage starting.

Answer / k.prakashchandra

Instead of bulbs voltmeters can be employed

Give me the calculation steps to design an electromagnet to be work in 230V 50 Hz AC Supply. Also give force that is created by that electromagnet when it gets energized.

0 Answers   GE,

---

Why C.T secondary s2 done earthing?

4 Answers  

---

Purpose of lighting transformer.

2 Answers  

---

what is the design factor that affects the size of a motor ?

3 Answers   Reliance, SGI,

---

Initially motor starts with star connection ,after few timing changes to delta connection, why the motor should run continously in star connection,it gives high torque & low current?

3 Answers  

---

---

Am i eligible to get electrical supervisor licence? As i did diploma as well as degree in Electrical Engg. in June 2011. Now i am working in 15 MW Power plant from 2 mnths. i belongs to Maharashtra.

1 Answers  

---

what happens if dc supply is given and the remedies for it.

0 Answers  

---

In APFC panel, Why on dealy timer is used in Capacitor controlling circuit?

1 Answers  

---

what is sf6 where it is use & working or function ?

5 Answers  

---

Does all the output contacts (N/O as well as N/C) of a Numerical relay operate when relay receives a binary input/inputs or contacts are designated to specific logic input/inputs and only these contacts operate?

0 Answers  

---

What is Scheme Test of High Voltage Switchgear. Which tests it includes.

0 Answers   Siemens,

---

how to interlock 3 nos MCCBs using under voltage coil. please provide me circuit diagram?

0 Answers   Honeywell,

---