Answer / singa

CTs are having both measuring as well as protection cores.

Measuring cores:
In a HT lne, current value is in terms of few hundrest to
kilo amps. In practical these cannot be measured by meters
direclty. Hence the current in the transmission line will
be stepped down to the standard values for example 2000/1A.
THis refers to the flow of 1A at CT secondary when 2000A
flows in HT line.

Protection core: As the fault current is very high during
the time of fault, this increase in current is used to trip
the faulty section. In order to sense the fault current,
protection cores of CTs are used to feed the protection
relay.

Answer / suresh

actually Ct is measuring unit, according our require ment
we can take 2 or 3 core for metering and protection. for HT
lines any fault will came like LG fault we can rectify the
fault by using CT it is a High voltage to mesurement
control volatge will be step down

Answer / dhaval patel

While in line, if the CT terminals get open, it can result
in heavy faults in CT core. To prevent developing of such
higher voltage at the secondary terminals of the CT, it
shall be protected.

Answer / k.prakashchandra

And without CTs you can not measure HT current.

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