Answer / lalit barsker

vacuum circuit breaker is a device which is used to isolate
the faulty part of the power system from healthy part of the
power system & is used in switchgear.WHEN WE WANT TO SERVICE
OR MAINTEINANCE OF ANY SUBSTATION OR WANT TO CLEAR THE FAULT
DURING THAT CONDITION WE CAN ISOLATE THAT PART OF POWER
SYSTEM SO THAT WE CAN WORK IN THAT CONDITION ISOLATOR IS
OPEN AND SUPPLY CAN BE INTERRUPTED.

Answer / purushotham naidu.

Vaccum circuit breaker,as the name indicates is used to
break the circuit in faulty conditions and Arc quenching
medium is Vaccum. Isolator, as the name indicates isolates
the part of the system on occurence of fault without
actually being quenching/interrupting the arc....

Answer / mahesh m

The vaccum c.b are used to dissconnect the ckt when fault
accurse in the ckt,aswell as the vcb is used to break the
ckt in abnormall condition,in tn the name indicates the
isolators are used to isolates the ckt and the supply can
be intterupted by the mains.

Answer / ramakishore karri

the purpose of the vacuum circuit breaker is to isolate the fault system after the occurance of the fault. So that circuit breaker contacts open, in case of isolator it isolate the power for maintenance of the sub station as u like depends on us and it should not require any relay for finding the type of fault and interrupt the supply. In case of circuit breaker relay is required for finding the type of fault and it interrupt the circuit breaker.

A 100 MVA transformer may be cooled with?

6 Answers   HCL,

---

How can calculate HT side VCB? For example I have 1250 KVA load what will be HT side VCB Amp.range and what size XLPE cable I use for HT side.

2 Answers   NASSA, Orchid, SB Automation,

---

Why alternators are rated in KVA?

12 Answers  

---

HOW TO SIZE THE TRANSFORMER OR WHAT ARE THE STEPS INVOLVED IN FINDING THE SIZE OF THE TRANSFORMER FOR GIVEN LOAD SAY 2000KW ?

1 Answers  

---

What happens if a +vely charged particle is placed in the centre of a room and assume that the north side wall is having magnetised with north polarity and south side wall is magnetised with south polarity. In which direction the particle will move

5 Answers   BSNL,

---

Why field rheostat is kept in minimum position while armature rheostat at maximum position?

0 Answers  

---

What is accuracy of a measurement?

0 Answers  

---

What is the effect of solar radiation on the design of an Isolated Phase Busduct?

0 Answers   Exide, Punj Lloyd Ltd,

---

Why there is a current in neutral line

3 Answers   Honeywell,

---

WORKING PRINCIPLE OF HALOGEN LAMP & MEQUERY LAMP

1 Answers  

---

what is the difference between a feeder and a cable?

3 Answers  

---

If a HV Underground Cable (13.8KV) is layed in the ground below 1.5 Mtrs and any building construction is done on the Cable route. IS this allowable or Not? What should be the clearance. As per ISO construction on HV cable route is safe or Not? Why? Can any body suggest the site for my question?

1 Answers   ZCL,

---