Answer / dhiraj banka

Class b SPD is for lightning surges & class c SPD is for switching surges.Class B+C protects both from lightning & switching surges.

Answer / vanraj

For surge arrester (lighting arrester) class defines the
capacity of energy can dissipate by SA.

Class in generally not defined by B & C but it defined a
class 2 , Class 3 , Class 4 & class 5 for sub stations.

For 145 kv (110,132 kv ) class 2
For 400 kv ( 400 kv) class 3
For 540 kv (generally not use in india) class 4
For 765 kv Class 5

if z transform lies in ROC then. a)system is stable b)inverse of system is stable c)both system and its inverse are stable.

1 Answers   CCP,

---

How do I calculate/select Droop CT ratio for various capacity of generators?

0 Answers  

---

Why Closing coli supervision is not required for Circuit breaker.

1 Answers   JSW,

---

How does a tertiary winding filter harmonic(espcially 3rd one) from entering into load system?

0 Answers  

---

n1 =1000 n2 =?;v1 =200:v2 =400

1 Answers   APGenco,

---

How much heat will a 2500 KVA transformer will generate ?

5 Answers  

---

Thumb rule for capacitor bank calculation

1 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,

---

What is means by MacAdam Ellipse?

1 Answers  

---

what is STUB protection in tranmission system and switch yard area?

9 Answers   KSEB, Power Grid,

---

how to calculate the change over time for star delta starter for different KW motor?

0 Answers  

---

Give some example of fault limiting devices?

0 Answers  

---