7.2. Example 2 winding transformer protection connection
An application example of 2 winding transformer differential relay AQ-T257. Regular differential
scheme with high voltage side restricted earth-fault protection.
Figure. 7.2. - 168. Application example for AQ-T257 2 winding transformer protection
7.3. Trip circuit supervision (95)
Trip circuit supervision is used to monitor the wiring from auxiliary power supply trough IEDs binary
output and all the way to the open coil of the breaker. It is recommended to know that trip circuit is on
healthy state when the breaker is closed. Application scheme for trip circuit supervision with one digital
input is presented in gure below.
AQ-T257
Instruction manual
Version: 2.00
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