SIEMENS 6ES5951-7LB12

Siemens SIMATIC S5 Power Supply 6ES5951-7LB12 Description The Siemens 6ES5951-7LB12 is a power supply module for the obsolete but widely used SIMATIC S5-115U PLC series. It provides reliable and regulated DC power to the CPU and other modules within the S5 rack. This unit is essential for maintaining existing automation systems that rely on the S5 platform, offering a direct replacement for failed or aging units. With selectable input voltage and multiple DC outputs, it is a versatile component for S5-115U configurations. Specifications Manufacturer: Siemens Product Series: SIMATIC S5 Part Number: 6ES5951-7LB12 Input Voltage: 115V / 230V AC (Selectable) Input Frequency: 47-63 Hz Output 1: +5V DC, 7A Output 2: +5.2V DC, 2.5A Output 3: +24V DC, 0.35A Total Current Capacity: 15A For use with: SIMATIC S5-115U systems Application This power supply is specifically designed for the main rack of a Siemens SIMATIC S5-115U programmable logic controller. It is commonly found in older manufacturing, process control, and automation applications that have not yet been upgraded to modern systems. Country of Origin This product is manufactured by Siemens in Germany. CO2 Impact Reusing this power supply module saves an estimated 60 kg of CO2 compared to producing a new one. This is equivalent to the emissions from driving a standard car for approximately 300 kilometers. Availability This is an obsolete item, available as a refurbished spare part. Stock is limited. Order now from profideals for expert support and fast delivery. FAQ Question?What is the purpose of the ‘Voltage Selector’ switch? Answer?The switch allows you to configure the module’s input voltage to match your local power grid, either 115V AC or 220/230V AC. Incorrectly setting this can damage the unit. Question?Is this power supply compatible with other SIMATIC S5 racks, like the S5-100U or S5-135U? Answer?No, the 6ES5951-7LB12 is specifically designed for the SIMATIC S5-115U PLC system rack. Using it with other S5 families is not recommended as the power ratings and backplane connectors may differ. Question?What does the ‘BATT LOW’ indicator mean, and what type of battery is required? Answer?The ‘BATT LOW’ LED indicates that the external backup battery, used for retaining the PLC program in RAM during a power outage, is depleted. It requires a 3.4V to 3.6V lithium battery, which connects to the ‘EXT BATT’ terminals. profideals is not an authorized distributor, reseller or representative of the products featured on this website. All product names, trademarks, brands and logos used on this site are the property of their respective owners. Last Update: Friday, March 13, 2026