Equipment must withstand physical stress during its operational lifespan. IEC 61869-1 specifies:
Power-frequency voltage withstand tests on primary and secondary windings. iec 618691 pdf
Regional standard authorities like ANSI (USA), BSI (UK), DIN (Germany), or ISO members offer licensed copies. iec 618691 pdf
Standardized identification for primary and secondary terminals to prevent wiring errors during installation. Testing Framework under IEC 61869-1 iec 618691 pdf
Concise checklist for engineers (pre-installation)