User manual for the Tianneng DSI 5121 transformer differential protection device, covering specifications, functions and installation.
The DSI 5121 is a transformer differential protection device designed for substations up to 110 kV. It implements IEC 61850 communication, offers programmable protection and control functions, and provides a user‑friendly HMI with a large LCD and programmable indicator lights.
The manual describes the hardware architecture, power supply requirements, protection principles, configuration procedures and maintenance guidelines, including detailed wiring diagrams and parameter settings. This manual is written in Chinese.
| DC Voltage | 220 V or 110 V |
|---|---|
| AC Current (In) | 5 A or 1 A |
| Frequency | 50 Hz |
| Power Supply Voltage | DC 220 V or 110 V ±20 % |
| Protection Current Working Range | 0.1 In – 20 In |
| SOE Resolution | ≤ 2 ms |
| Time Synchronization Accuracy | ± 1 ms |
| Dielectric Strength | 50 Hz AC, 2 kV (1 min) |
The device can be supplied with either 220 V or 110 V DC.
It operates at 50 Hz.
The protection current works from 0.1 In up to 20 In.