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 we are using earth pit in sub stations.?

0 Answers  

---

how to claculate earth strip size for 1500kVA transformer for neutral and body

4 Answers  

---

star delta advantage and disadvantage?

2 Answers  

---

how many units will 100 kvar capacitor consume for one day?

2 Answers   Philips,

---

According to conduit size which size wiring & how many wires can we provide wires in conduit & how can we select conduit size accordingly?

0 Answers  

---

---

In power transformer tappings are provided on A high voltage side B low voltage side C In middle of both the windings D both high and low voltage side

2 Answers   NNN,

---

What are the two basic types of transformers?

0 Answers  

---

what is voltage present between to phases in a three phase motor?

1 Answers  

---

What is the theoretical reason for the size of a zig zag grounding transformer to be 1.732 times less than that of a wye-delta grounding transformer used for the same application?

0 Answers  

---

what is the use of power factor ? where its applicable ?

4 Answers  

---

In protection core of a C.T. why Knee pont voltage is greater than SLV and in metering its viceversa?

2 Answers  

---

Can anyone tell me how a 12v battery is transformed to 20,000v at the spark plug

6 Answers  

---