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Engineered for SIMATIC S5 Backplane Power
This unit supplies stable 5V DC power to the entire S5 rack. It provides reliable energy for the Siemens 6ES5955-3NC12 system. You will find this power supply in large SIMATIC S5 configurations. Unlike standard PSUs, this version delivers 20 Amps for densely populated racks. It powers multiple CPU, I/O, and communication modules simultaneously.
Technical Specifications & Physical Dimensions
We designed this power supply for high-current industrial applications. The table below presents all verified technical specifications.
| Parameter | Specification |
|---|---|
| Physical Dimensions (W x H x D) | 250mm x 125mm x 130mm |
| Total Weight | 2.6 kg (2600 grams) |
| Input Voltage Range | 120V AC or 230V AC (selectable) |
| Input Frequency | 50/60 Hz ±5% |
| Output Voltage | 5V DC nominal (4.9V – 5.1V) |
| Output Current Rating | 20 Amps continuous |
| Output Power | 100 Watts maximum |
Functional Architecture and Protection Features
This power supply connects to the S5 backplane via a dedicated bus connector. It uses a linear regulated design for ultra-low noise output. You can select 120V or 230V input using a red slide switch. Moreover, the unit includes electronic foldback current limiting. This component reduces output current during short circuits. Consequently, the PSU survives indefinite overload conditions without damage.
Installation and Operational Guidelines
The Siemens 6ES5955-3NC12 achieves 75% efficiency at full load. It requires 100mm clearance on all sides for cooling airflow. You must set the voltage selector before connecting line power. Always use a 10 Amp circuit breaker on the input side. This practice protects the internal wiring from faults. Furthermore, the unit includes a green LED for output OK indication. This feature provides immediate visual confirmation of proper 5V operation.
Physical Characteristics and Environmental Limits
This power supply has a rugged, ventilated metal enclosure. Its substantial 2.6 kg weight reflects the linear transformer design. The layout follows Siemens standard S5 rack specifications. Therefore, it fits securely into the leftmost slot of any S5 rack. The unit requires no additional mounting hardware for installation. In addition, it maintains stable operation between 0°C and 50°C ambient temperature. You can store this PSU safely between -25°C and 85°C.