Protection Engineering Basics and Schemes Protection Engineering | Page 25

1.1.8.1 Method:
 Take one conductor
 Take CT need to be tested
 CT must not be placed in any circuit , but at your
Testing facility or near Testing equipment
 Place your conductor in air gap of CT
 Take One battery and in series of battery connect
one push button , then connect the terminals to the
Conductor
 Your Ammeter (dynamo Type) will be connect with
both terminals of Secondary
 While this arrangement completer , press push
button which you knew remain open till press, when
you press push button , the dynamo type ammeter
show flicking of needle from zero value to positive
value , and when you release your push button
,needle flick towards negative value then it’s means
your CT polarity is correct and in that same position
you need to connect your CT to test block, but let
suppose when you press push button if the needles
show no flicking toward positive value or move
toward negative value or remain jam on zero position
it’s means polarity is incorrect.
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