Answer / naresh kumar dhal

making capacity=2.55*symmetrical breaking capacity

Always ckt breakers are rated in its symmetrical breaking
capacity.It is the rms value of fault current that a ckt
breaker can handle for short duration of time,which is
called short time rating.
If breaker is rated 10 mva,then its symmetrical breaking
capacity is 10mva.i.e root3*v*I*10-6=10mva,from this u
calculate current.Which is the symmetrical breaking current

Answer / pillay

making capacity of a circuit breaker means when you switch
on the breaker the breaker can operate safely or withstand
upto the stated amount.

The same applys to breaking capacity of a breaker which
means when it switches off it can withstand up to the stated
amount at the time of offing. The unit used is usually KVA
or MVA.
Some breakers can have a high breaking capacity but a low
making capacity. This means when switching on it should not
be loaded but can be switched OFF with a high load.

Answer / vs

ans 1 is absolutely wrong .ans -2 is right .making capacity
is always higher than breaking capacity .

There is 3phase power cable from 1 point to the other point which is 100m away. Two point equipped with power meter and recorded 1st point is 205kW while the 2nd is 202kW and each phase average carry 400amps. To calculate the resistance of the 3phase power cable, is the formula using will be P=I2R?

3 Answers  

---

how can calculate static 3phase 4wire CT & PT operated energy meter constant when calibrating using refference meter suppose we have 11kv/110v PT and 30/5A CT, the meter constant is 160imp/kwh, where meter is showing MW energy? give me solution which constant i feed in my refference meter for calibration of energy meter?

3 Answers  

---

The ratio of white balls and black balls is 1:2. If 9 gray balls is added it becomes 2:4:3. Then what is number of black balls ?

3 Answers   CTS,

---

why do we use star-delta starter. what is its need?

6 Answers  

---

What is the advantage of AC supply?

5 Answers   PSU,

---

1. which type of transformer connection is preferred in case of power supply transformers? (A) Star/Star (B) Delta/Delta (C) Star/Delta (D) Zig Zag/Star 2. In a power transformer usuall which winding is closer to the core? (A) Primary winding (B) Secondary winding (C) Low Voltage winding (D) High Voltage winding 3. The power factor of a purely inductive load is (A) Zero (B) Lagging (C) Leading (D) Unity.

9 Answers   CECRI_Central_Electrical_Research_Institute,

---

how to calculate the current carrying capacity of a 25 & 16 kva distribution transformer.

2 Answers  

---

What happened ,If 3 phase clearance not maintained in 33KV Line,11KV LIne etc?

0 Answers  

---

What differance between Circuit brekar and Isolater?

14 Answers   TATA,

---

what are the materials used in HRC fuse

3 Answers   Bhel,

---

HOW to speed control of induction mototr using scalar control

3 Answers  

---

1. Why a DC motor starter is called 3 point starter

21 Answers   ABB, CG, College School Exams Tests, Crompton Greaves, Infosys, Siva,

---