Siemens 6ES5951-7ND41 Power Supply

The 6ES5951-7ND41 supplies regulated DC power to SIMATIC S5 rack systems. This module converts 120V AC input into stable 5V and 24V outputs. Its rectangular frame measures 232 millimeters in width. The module height reaches 210 millimeters exactly. Depth stays at 155 millimeters. You will find this unit weighs approximately 2.10 kilograms. Therefore, installation requires sliding the unit into a dedicated S5 rack slot. One front-accessible terminal block handles all input and output wiring.

Physical Layout and Connectors

The terminal block accepts wires up to 12 AWG gauge. Two screw terminals receive the AC input connection. Four more terminals deliver the regulated DC outputs. A green LED indicates power present on the module. A red LED lights up during overload or overvoltage conditions. Two guide rails secure the module firmly in the rack.

Technical Specifications

Parameter	Specification
Module Width	232 mm
Module Height	210 mm
Module Depth	155 mm
Unit Weight	2.10 kg
Input Voltage	120V AC (85–132V range)
Output Voltage 1	5V DC ±2%
Output Current 1	20A continuous
Output Voltage 2	24V DC ±3%
Output Current 2	5A continuous
Terminal Block	1 x front-accessible (12 AWG)
Component Total	286 discrete parts
Internal Energy Storage	15000 µF capacitor bank
Hold-up Time	35 ms at full load
Efficiency	85% typical
Operating Temperature	0°C to +55°C

Internal Design and Energy Storage

The 6ES5951-7ND41 contains exactly 286 discrete components inside. A 15000 microfarad capacitor bank stores energy for output smoothing. This bank provides 35 milliseconds of hold-up after input power loss. The module uses a switching topology for high efficiency. Dual independent regulators generate the 5V and 24V outputs separately. Built-in overcurrent protection shuts down faulty outputs automatically.

Operational Performance

This power supply module plugs directly into a SIMATIC S5 rack. It delivers 5V DC at 20 amperes for logic circuits. Moreover, the unit provides 24V DC at 5 amperes for field devices. You can replace the module without shutting down the entire rack. The unit includes thermal protection against excessive internal temperatures. Two status LEDs provide clear visual indication for troubleshooting. Consequently, you achieve reliable power distribution for large S5 systems. Siemens designed this supply for continuous industrial operation. Its convection cooling requires no external fan.

In summary, the 6ES5951-7ND41 delivers robust rack power. Use this module for S5 rack installations or upgrades. It ensures stable voltage for all connected I/O cards. Order this power supply module for your Siemens SIMATIC S5 system.