This guide covers power design principles for Siemens S7-300/400 systems, including CPU, rack, module, and sensor power, along with I/O wiring precautions.
This document provides guidelines on power design principles for the Siemens S7-300/400 programmable controller system. It details considerations for CPU power, rack power, module working power, and sensor power to ensure system reliability in industrial environments. Key topics include grounding methods, power distribution strategies, isolation techniques, and redundancy designs using dual AC/DC sources or UPS systems. This manual is written in Chinese.
| Supply Voltage (General) | AC220V, 50HZ |
|---|---|
| Isolation Voltage Limit (Eiso) | 75VDC or 60VAC |
| Power Reserve Margin | 0.5 to 1 times |
Design should consider reasonable grounding, anti-interference capability of the power system, and redundancy to prevent PLC power loss if external equipment fails.
If the potential difference between Mana and M exceeds Eiso (75VDC or 60VAC), a connection must be established. Otherwise, they remain electrically disconnected.
Use a DC-DC converter to isolate the input and output loops of the circuit, which improves the system's ability to suppress electromagnetic interference.