Answer / srinivasan.

open-300 millisec-Close /open-3min-Closeopen - means the
circuit breaker is capable of performing the above
operations even at full shorcuit currents.
At the same time the circuit breaker should not be allowed
to operate lesser than these timings.For example open-20
millisec-Close open-1 min-close/open.

This type of breakers are called single shot autoreclose
breakers.
Immediately after a fault breaking,we can do close open the
circuit breaker.

This sequence is tested during type testing only.

Answer / k.prakashchandra

CO means closing followed by opening.

why should a transformer be never connected to dc supply

5 Answers  

---

In more then 1 phase bulb will glow are not?if yes then how it will glow?

2 Answers  

---

What is knee point voltage of transformer?

0 Answers   Nabard,

---

WHTA IS LIMT OF LEAKGE CURRENT OF 11 KV 1 CORE 1000SQ.MM. XLPE CABLE.LOAD ON CABLE IS AROUND 600AMP .LENGTH 500 MTRS.

0 Answers   L&T,

---

will we get shock from dc?

12 Answers   L&T,

---

---

For Bus duct hi pot test, where we want to connect the return and ground leads?

2 Answers  

---

what is AVR and tell principle and working?

10 Answers   ITC Infotech, MIOT Hospitals, YCC,

---

what is iron loss?

4 Answers   RRB,

---

How is magnetic leakage reduced?

0 Answers  

---

My energy meter ratio is -/110/root 3,1A and connected line CT is 100/1,PT is 11kv/110 so what is the MF for meter

1 Answers   Apollo,

---

How to calculate load taken by a cable?

3 Answers  

---

What is reverse power relay?

0 Answers  

---