Short Circuit Fault

It is actually the relay which sense the abnormalities in the systems by monitoring the basic parameters like voltage, current and frequency with the help current transformers potential transformers etc .The relays will sense the fault condition and gives the trip command to the trip coil of the circuit breaker which cause the breaker mechanism to open the contacts.

Ok then what is the relay name and reference number in the circuit?

How about "fault protection relay"?

_{It is unlikely to be called "Boris".}

See there are n number of fault protection relay.I just need only for short circuit fault.

Well, there will be an "as-built" wiring diagram for the installation somewhere nearby. What does it say?

I have never seen that drawing for medium voltage panel I know only about

Low voltage electrical panel that's why I am rising question with you otherwise I can read the drawings

Kindly give me the answer don't ask any new question with me.

Here's an answer, then: telephone the panel manufacturer, whose details will be on the front of it, and obtain a copy of the missing drawing(s) for the panel. Kindly do that first, for it's something that, in the absence of any other information to hand, any other CR4 reader would need to do.

You should learn about circuit breakers for LV,MV and HV.

ITs operating principles, features etc.

Basically all these circuit breakers can be switched ON, switched OFF manually or automatically, locally or remotely.

Basic breakers will not have any sensing device for current or voltage monitoring.

Current or voltage monitoring is done by other devices and made to operate at particular algorithms then these devices are called relays.

These relays make the Circuit breakers switch off.

In LV breakers these features of current /voltage monitoring are built in and called releases.

Therefore for LV circuits with LV breakers , there is no need for separate relays

Whereas in the case of MV or HV breakers there is no built in device.

Therefore for HV or MV circuits with HV or MV breakers ,separate monitoring relays are required to switch off the breakers.