Answer / niranjan

· The system earthing and safety earthing are interconnected and therefore fault current flowing through system ground raises the potential of the safety ground and also causes steep potential gradient in and around the Substation. But separating the two earthing systems have disadvantages like higher short circuit current, low current flows through relays and long distance to be covered to separate the two earths. After weighing the merits and demerits in each case, the common practice of common and solid (direct) grounding system designed for effective earthing and safe potential gradients is being adopted.

Answer / siva kumar

during fault conditions the fault current fed from transformer neutral.So the earth pit which is connected to neutral has to supply fault current.
supplying of quantity of fault current by earth pit has limitations such as soil type.CIPipe lengh etc.
if you connect neutral earth pit to substation mat, the mat will supply the fault current.

it is just like earth as big water reservoir and water as current. If more and more parlel pipe lines are laid more quantity of water can be dischrged quickly.

Answer / pankaj agarwal

as the short circuit fault devlops in the system the fault
current flows from fault point into the neutral. in the
absense of interconnection, all the fault current has to
travel through ground which have high resistivity so the EF
current flowing in the system may not be sufficient to
operate the EF trip relay. in the interconnected system EF
current have alternate and less resistive path so fault
gets cleared fast.

Answer / nipesh

but we do metal glanding in secondary side cable termination in both side, transformer and PCC panel (LT Panel), in this case transformer body earthing and substation earthing both are joint through metal gland, is this safe for transformer and other equipment?

if we supply DC power to AC transformer then what its result?

15 Answers  

---

What is the reason for low voltage in houses?

19 Answers   Maytas,

---

why we condut tan delta test i want brief explain?

3 Answers  

---

What is RTCC in a transfomer and specify its function.

11 Answers   MCB, Vodafone,

---

what is the function of turbo in dg sets

1 Answers  

---

---

v=I*R, i.e V is directly proportional to I. now P=V*I. so V=P/I. thus v is inversely proportional to I. so what is the correct one? If both are correct than for which kind of condition this 2 differ

3 Answers  

---

what is the difference between core & shell type transformer ?& where we use those transformers ?

10 Answers   BNCET,

---

what happens in the short circuited secondary transformer,if the resistance of the short circuit is increased gradually?

0 Answers   IIT,

---

the electric traction poles having 3 cables n two cables touches with a insulator (or any) another one separated but it will be running 1-phase why?

4 Answers  

---

why do we require two lines one phase and a neutral for an ac transmission..is neutral potential zero..?if yes y carry a neutral line from generating station itself...why dont we take it from ground

1 Answers  

---

WHAT IS SITTING AMPS IN OVER-LOAD RELAY FOR 1PH OR 3PH MOTORS?IF ITS NAME PLATE GIVEN MAX AMPS 10AMPS?

0 Answers  

---

what is the efficiency of thyristor

0 Answers  

---