Answer / greenhat25

When a fault occurs, a current flows in th secondary winding
of th current transformer.
If th current is greater than th setting of th relay, th
electromagnet is energised and attracts th armature.
The action of th armature closes and opens th normally open
and close contacts respectively, thereby closing or opening
th trip circuit.
The shunt trip coil or UV trip coil is energised or
de-energised and th circuit breaker will trip.

Answer / avd

In continuation to above answer, there are different
schemes to detect earth fault in the system
1. By using residual connections of three phases CTs
2. By using CBCT
3. By using a neutral CT at transformer neutral point.

what is VSWR?

1 Answers  

---

wich type of cable is selected for wiring of 20hp motor?

5 Answers   Alchemist,

---

how to calculate the KVAr for an motor for improving the PF

3 Answers  

---

why neutral grounding transformer is used for generator and why it is not used for transformers?

1 Answers   UPCL,

---

What is the alternate solution for testing of polarity by using polarity tester while its milli ammeter does not works?

0 Answers  

---

Why high voltage lines (overhead ) are called high tension lines?

8 Answers  

---

what are the affects of loose connection in electrical circuit.

14 Answers   HP,

---

State and define norton’s theorem?

0 Answers  

---

hai every bodi please let me know the test procedure for lightning arresters.

2 Answers  

---

what will happen if multimeter(selector switch at DC voltage) and terminal at current is connected to DC supply?

0 Answers  

---

What are the fire Estingushers use in electrical fire?

3 Answers  

---

Compare salient pole and Hndrical rotor machines.

1 Answers  

---