Answer / m.s.srinivasan

Functioning of the RCCB as well as ELCB are the same.
A CT is used to measuer the difference of current in the
circuit being protected. For that all the 3 cores + neutral
of the circuit is passed thro' the CT. For a normal healthy
circuit, difference of the net current will be Zero. Hence
the CT will not sence any current. When the current passing
thro the CT finds a path thro' the some other way ( by
earth ) , an unbalance is created and the CT sences the
unbalance and actuate a trigger to stop the power flow.
The unbalance current over which the RCCB to operate is
given for individual device. Normaly this would be
30ma,100ma,300ma and the selection of the devices is based
on the application.

IS RTCC AND OLTC REQUIRED FOR 500 KVA 11KV/433V TRANSFORMER FOR AN INDUSTRY?

7 Answers   IGCAR, TNEB Tamil Nadu Electricity Board,

---

Why the Motor takes High Current in Starting time?

5 Answers  

---

We have 800KW motor operating at 6600Volt,50 Hz supply.During 1st startup it tripped on overcurrent trip.It's FLA is 88 Amps.The K factor of Thermal overloaaad was set on .94 initially.then we set at 0.97 and then it started fine.i dont understand why it tripped first?What are the protections which comes in picture during starting ?

6 Answers  

---

what is thyristor, how is it works

1 Answers  

---

Why overhead transmission line in triangular shape?

2 Answers  

---

What is double throw isolator and single throw Isolator.

1 Answers   KSEB, L&T, Siemens,

---

Why the moulded plug comes with domestic appliances instead of assembled plug like anchor, Vinay 5/15 A.

0 Answers  

---

draw vector diagram and +ve,zero sequence diagram of symmetrical three phase fault.

0 Answers  

---

where do we connect tap of tap changer, to H.V. side or L.V.side? and why?

5 Answers   Vedanta,

---

Power systems

0 Answers   LB Engineering,

---

how to measure earth pit resistance

7 Answers   BARC, BYD Electronic, Construction,

---

Dear All we are having a problem in G120 BOP showing alarm A0503, F0052, F0060 we can not remove fault alarm ,Please any body help us. kowsar

0 Answers   TCCL,

---