Siemens 6ES5951-7LD11 Power Supply | S5-155U PS 951 Module

Technical Overview

The Siemens 6ES5951-7LD11 is a PS 951 power supply module for the SIMATIC S5-155U programmable controller series . This unit delivers the high-current DC power that large S5 systems require to drive CPUs, communication processors, and numerous I/O modules. The module provides flexible output configurations with selectable current ranges for the 5V DC output. Its robust design includes comprehensive protection circuits against overcurrent, overvoltage, and short circuits . The Siemens 6ES5951-7LD11 occupies two rack slots and requires a C-size battery for backup functionality .

Technical Specifications

Parameter	Specification
Manufacturer	Siemens
Model Number	6ES5951-7LD11
Product Type	Power Supply Module / PS 951
System Compatibility	SIMATIC S5-155U, S5-135U
Input Voltage	115/230 V AC, 50/60 Hz
Output 1 (5V DC)	10A or 20A (selectable via DIP switch)
Output 1 (5V DC) Alternative	7A without fan / 15A with fan subassembly
Output 2 (24V DC)	0.35A (PS 951 standard) to 5A
Backup Battery	1 x C-size battery required
Protection	Overcurrent, overvoltage, overtemperature, short circuit
Efficiency	>85%
Slot Requirement	2 slots (dual-width)
Dimensions	Approx. 100 x 290 x 210 mm
Weight	2.0 – 3.0 kg
Operating Temperature	0°C to +60°C
Storage Temperature	-40°C to +85°C
Protection Rating	IP20
Certifications	CE, UL, CSA
Country of Origin	Germany

Key Features

High-Capacity Dual Output Design – The module provides a selectable 5V DC output (10A or 20A) and a 24V DC output, accommodating various system configurations .

Selectable Current Configuration – Users can set the 5V output to 10A or 20A via a DIP switch, matching the power requirements of different S5-155U system sizes .

Comprehensive Circuit Protection – Overcurrent, overvoltage, overtemperature, and short-circuit safeguards prevent damage to connected modules and ensure system reliability .

Flexible Cooling Options – The module supports operation with or without a fan subassembly, with current ratings of 7A or 15A at 5V DC respectively .

Industrial-Grade Reliability – The module operates across a wide temperature range and features robust electromagnetic compatibility for challenging factory environments .

Diagnostic LED Indicators – Front-panel LEDs display power status for each output, simplifying troubleshooting.

Applications

The Siemens 6ES5951-7LD11 powers large-scale SIMATIC S5-155U systems in manufacturing, process control, power generation, and chemical processing. It is essential for legacy S5 system maintenance and upgrades.