Siemens 6ES5955-3NC41 PS955 Power Supply

Core Power Delivery for S5-135U/155U Systems

The Siemens 6ES5955-3NC41 is a PS955 power supply module for the SIMATIC S5-135U and S5-155U programmable logic controller families . This unit converts AC line voltage into stable DC outputs for the CPU, I/O modules, and backplane bus. It provides a main 5V DC output at 18A and an auxiliary 24V DC output for field devices . Consequently, it is an essential component for building reliable S5-135U/155U automation stations.

Designed for Large-Scale Automation Systems

The PS955 accepts a wide AC input voltage range of 230/120V AC, making it adaptable for global installations . Its robust design delivers a total output power of 955W, making it a high-power option within the S5 line . The module’s efficient switching technology and filtering circuits ensure a low-ripple, “clean” 5V supply, which is critical for stable CPU and high-speed communication module operation .

Technical Specifications and Physical Attributes

The module provides a high 18A current capability on its main 5V rail and incorporates comprehensive protection mechanisms . It features an IP20 protection rating, measuring 33.7 x 45.8 x 11.3 cm and weighing approximately 6.22 kg . The following table details its key physical and functional parameters.

Parameter	Specification
Manufacturer / Series	Siemens / SIMATIC S5-135U/155U
Product Model	6ES5955-3NC41
Module Type	PS955 Power Supply Module
Output Voltage 1	5 V DC @ 18 A
Output Voltage 2	24 V DC (Auxiliary)
Input Voltage	230 / 120 V AC
Protection	Overload, Short Circuit, Overvoltage
Weight	approx. 6.22 kg
Product Status	Discontinued

Application in Legacy S5 Systems

Plant engineers rely on this power supply to maintain and support existing S5-135U/155U-based automation systems . It is a critical component for industries where these legacy controllers remain in daily use. Therefore, sourcing tested units is essential for lifecycle management of classic Siemens automation platforms.