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 .

What are the protection schemes used for protection of transformers ?

3 Answers   Engineers India Limited,

---

line diagram for mcb , mccb , rccb .

1 Answers  

---

what is bus pt and what is the function of it

2 Answers  

---

which starter is used for synchronous motor

18 Answers   APTransco, IBM,

---

why in three phase 440 circuit in all phase current is almost equal L1-35 A,L2-34 A ,L3-31 A but in nutral when i check with clamp meter it shows 25 A?

4 Answers   OPS,

---

please mention the minimum IR value for different voltage systems

6 Answers  

---

Why we use circular(Stepped) cross section in transformer core?

0 Answers  

---

how the capacitance is caluclated if the load is varying to keep the power factor constant(above0.95)

1 Answers  

---

what are the different types of transformers in present? which transformer is efficient?

1 Answers   TATA,

---

Why IGBT is very popular nowadays?

3 Answers   TVS,

---

relation between power station capacity and voltage level?

0 Answers  

---

Why Power generation in India is at 50Hz while in America its 60Hz so is there any advantage/Disadvantage of this ??

38 Answers   Australia Visa, College School Exams Tests, Fiat, InfoPlus, L&T, NTPC, TCS,

---