Answer / ritesh ashok jaiswal

CT SATURATION MEAN CORE LOSS THE CAPACITY OF HOLDING THE
FLUX .THAT IS THERE IS NO OUTPUT AT CT SECONDARY .

15VA, class 10 P 10 CT means ratio error of prescribed
limit are constant up to 10 times rated primary current
when secondary burden is 15VA.

POLARITY CHANGE DEPENDS UPON FOR WHICH PURPOSE THE SAID CT
IS USED.

Measuring CT :-
 Use for measurement purpose.
 Accurate within the specified working range of
rated current (1% to 120% of rated current)
 Designed to saturate for more than 1.2 times
current to safe the measuring instrument from sever strain
caused by heavy over current.
 Accuracy is not required at high over current.
 High permeability core material with low saturation
level is most suitable ( Nickel- Iron Alloys).

b) Protective CT :-
 Use for protection purpose.
 A protective CT is required to faithfully transform
the primary current throughout it’s entire range from
normal load current to short circuit current.
 It should be accurate at all higher value of
current up to rated accuracy limit of primary current.
 To get high saturation level, grain oriented steel
are used for core.

GENERALLY the Saturation Point of measuring CT 30 VOLT &
Protection CT IS 300 V OR DEPENDS UPON MANUFACTURE TO
MANUFACTURE

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