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Reliable Energy Conversion for Industrial Control Systems
The Siemens 3RX9300 power supply converts AC mains voltage into stable DC power for automation components. This unit provides consistent 24 V DC output, ensuring reliable operation of PLCs, sensors, and actuators. Manufacturing environments demand robust power sources, and this model meets those requirements effectively.
Input and Output Electrical Specifications
This power supply operates from a wide input range of 85 V to 264 V AC, covering both single-phase and phase-to-phase connections. The unit delivers a nominal output current of 5 A at 24 V DC, with short-term overload capability up to 6 A. Total output power reaches 120 watts, supporting multiple I/O modules and field devices simultaneously. Furthermore, the integrated power factor correction achieves a value greater than 0.95, optimizing energy efficiency.
| Parameter | Specification |
|---|---|
| Model | Siemens 3RX9300 |
| Input Voltage Range | 85–264 V AC (50/60 Hz) |
| Nominal Output | 24 V DC |
| Output Current | 5 A (continuous), 6 A (peak) |
| Output Power | 120 W |
| Efficiency | > 90% (at full load) |
| Power Factor | > 0.95 |
| Hold-up Time | 30 ms (at 230 V AC) |
| Dimensions (W x H x D) | 70 mm x 125 mm x 120 mm |
| Weight | 0.85 kg |
Protection Features and Safety Mechanisms
This power supply incorporates multiple protection circuits for safe and dependable operation. The unit includes overvoltage protection that clamps the output at 28 V DC to safeguard connected loads. Short-circuit protection limits the output current to 6 A and automatically recovers after fault removal. Additionally, the module features overtemperature shutdown at 85°C, preventing thermal damage during extreme conditions.
Thermal Management and Cooling Design
The Siemens 3RX9300 utilizes natural convection cooling, eliminating the need for a noisy internal fan. The aluminum heatsink dissipates heat efficiently across the entire operating temperature range. This unit maintains full output capacity from -25°C to +55°C without derating. Above 55°C, the output current gradually reduces by 2.5% per degree Celsius. The ventilation slots allow unrestricted airflow, so maintain at least 50 mm clearance around the unit.
Installation and Connection Details
This power supply features a DIN-rail mounting mechanism for quick and tool-free installation. The spring-cage terminals accept solid or stranded wires from 0.5 mm² to 2.5 mm². A green LED on the front panel indicates normal operation, while a red LED signals fault conditions. The unit includes a DC OK relay contact for remote monitoring of output voltage status.
System Integration and Application Guidelines
You can use this power supply with any 24 V DC automation system, including Siemens S7 and S5 families. The unit connects in parallel with other power supplies for redundancy or higher capacity configurations. For optimal performance, connect a minimum load of 10% to maintain regulation accuracy. Always use properly sized circuit breakers on the AC input side for overcurrent protection.