SID‑2SJ is a high-precision sync-check relay designed for single-point automatic synchronization. It features four-level interlocking logic based on voltage difference, frequency difference, phase angle, and power angle, ensuring comprehensive safety in grid-connection operations.

The device supports automatic compensation for both voltage error and phase deviation, and real-time display of key electrical parameters from both the system and incoming sources. It requires no external power supply, and fully complies with the “25 Anti-Accident Measures” issued by the National Energy Administration.

SID‑2SJ supports multiple installation formats such as AK-11 and AQ-11, and can seamlessly replace traditional synchro-check relays. It is ideal for synchronization detection scenarios where high safety and reliability are essential within electric power systems.