I have been doing some work with some protective relaying and metering and have come to learn that the placement and orientation of a CT on a circuit determines the current phase angle for relaying purposes. If I understand it correctly, if the CT is oriented in one direction it will give a phase angle 180deg out of phase in which it was mouned the opposite direction. If the CT is mounted incorrectly then this phase angle can lead to errornaous readings. What causes this phase angle difference to be seen by the relay with the orientation of the CT?
I understand it has something to do with the polarity of the primary and secondary of the CT. The primary winding of the CT is the circuit or cable being measured, so is the polarity of this winding positive for the direction in which current flows. What dertermines weather the secondary winding is positive or negative polarity. How does this polarity matter for relaying and metering?
I understand it has something to do with the polarity of the primary and secondary of the CT. The primary winding of the CT is the circuit or cable being measured, so is the polarity of this winding positive for the direction in which current flows. What dertermines weather the secondary winding is positive or negative polarity. How does this polarity matter for relaying and metering?