The SDWJ series of small current grounding switch devices is a companion product of the new generation of substation automation systems independently developed by the Sanda Electronics & Electrical Co., Ltd. This product adopts the transient harmonic current selection principle and adopts advanced microcomputer digital technology. It has the function of rapid and accurate ground fault detection, and can realize single-phase ground fault selection to prevent non-fault phase insulation from being broken and phase-to-phase short circuit.
The Sanda SDWJ series is a small‑current ground line selection device designed for sub‑station automation. It uses a MCU+ARM architecture with a real‑time Linux OS, high‑speed sampling, and Ethernet/RS485 communication to identify faulted lines based on transient zero‑sequence current analysis.
The manual provides a detailed introduction, model description, hardware features, technical specifications, installation steps, wiring guidance, operation instructions, and warranty information. It also includes ordering requirements and optional communication options. This manual is written in Chinese.
| Power supply voltage | AC/DC 110V~220V |
|---|---|
| Power consumption | ≤20W |
| Operating temperature | -10°C to +55°C |
| Relative humidity | ≤90% |
| Bus segments | 1‑4 |
| Selection lines | 1‑60 |
| Zero‑sequence voltage | 100V |
| Zero‑sequence current | 1A or 5A |
| Alarm relay contact capacity | AC220V, 5A |
| Communication interfaces | RS485, CAN (optional), TCP/IP (optional) |
The device operates on an AC/DC power supply of 110 V to 220 V.
The total power consumption does not exceed 20 W.
The device supports 1 to 4 bus segments.
Up to 60 selection lines can be configured.