Answer / om

ct secondary can not be open circuited because if it is open
circuited then current in secondary is zero and secondary
voltage will become vary high and this will result in
saturation of core.

Answer / jayakumar.k

CT Secondary should never let open condition. Since there
is no opposing flux in secondary circuit Primary flux will
develop enormously high that would cause bursting of CT and
also damage to the person who is working with it.( Remember
induction principle)

Answer / raul

absolutely NOT bcoz during normal operating conditions, the
primary and secondary current are equal and opposite to
each other.........so the mmf of both primary and secondary
are in direct opposition........but secondary current is a
bit lesser than d primary current and this difference is
utilised in magnetising the core.......but if the secondary
is left opened then there will be no demagnetising mmf left
and excessive flux will b generated in the core and due to
this enourmous amount of voltage will b produced in the
secondary which is very harmful for life and CT also. also
there will be a loss of accuracy in future due to residual
flux left in the core.

Answer / muhammad nazim

A CT is basically a step-up transformer(from voltage point
of view).In the case of 400/1 A CT the primary turn is 1
(say the busbar)and the secondary turns is 400.How much
will be the primary voltage drop?? it will be in millivolts
for a busbar.So this millivolts multiplied by 400 will
cause just around a few volts (say 3 to 10V) for an open
secondary.But i have read that the secondary voltage will
reach a few kilovolts for a 400/1A CT at full load
conditions.My question is how it will reach a few kilovolts
and damage the CT on open secondary condition?As we have
seen above the max voltage wil be just in few volts.So
please someone

Answer / bharat sharma

Let us assume we have 600 V and 200 A on primary side of the
CT. Ct ratio is 200:1 In that case Secondary voltage would
be (600V x 200A)/1A = 120000 V. Would you like to leave
120000 V open circuit irrespective of current capacity of
secondary circuit?

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