Answer / ashif khan

before the selection,first we should know that it is single
phase or three phase load.in case 1-phase we use p=vicosф to
find out the load current but in 3-phase we use p=√3vicosф.
suppose it's 3-phase then load current=382amp.now add
minimum 25% safety factor to it.then it will be 475amp ,so
we can select C.B of 500amp current rating.

Answer / velusamy

Select based upon current rating
next 220kw using voltage

For Ex:
220kw
415v
means it will take arround 350 Amps so we can select the CB

more than the current with withstand capacity

Answer / sennapparajan

for 220kw load curent is 380 amps. so your breaker should
be min 1.5 times of full load current. so u can select 630A
breaker.

The capacity of the transformer is 20/25 MVA, Ratio is 132/11 KV, Vactor group YNyno. and impedance is 10.07%. As per the calculation the secondary current is 1312.2Amps. The maximum fault current the transformer should sustain is 13.030KA. How many times the transformer should sustain the maximum short circuit current of 13.030KA over a period up 1 Year. The transformer is repaired one & 10 Years old.

1 Answers  

---

why we measure ouput of transformers in kva.

1 Answers  

---

Is there a chance for a motor speed to become negative..?? What is the reason for such a phenomenon.? In that case does the motor works as a generator..???

1 Answers  

---

what are 3 factors when selecting a contactor for a job?

1 Answers  

---

What is measurement?

0 Answers  

---

---

HOW TO CHECK THE VECTOR GROUP OF A TRANSFORMER YD11?

0 Answers   Siemens,

---

What is multiplying factor of meter if the meter ctr and ptr is open type?

1 Answers  

---

Why Lightning arrester used? Can we use piece of iron as a core material of transformer, if No, why? In CRGOSS material what is meaning of cold rolled grain oriented? Why Impegrenation of Transformer is done? Properties of Insulator? what is phase angle? Testing of transformers (Routine & Monthly)?

6 Answers   NTPC,

---

what is meant by neutral Ct of a transformer and how it connected in transformer

4 Answers  

---

why voltage coil in wattmeter called as pressure coil why the pressure term is used in wattmeter?

1 Answers   NPCIL,

---

what is the acceptable limit value for Desolve Gas Analysis/

0 Answers  

---

Is there any problem about which the drive (inverter) doesn't show/display the alarm and/or fault but instead of this , it doesn't work ? I want to know that could there be any kind of problem in the drive when the drive doesn't display the alarm and/or fault ?

0 Answers   Siemens,

---