Siemens 6ES5955-3LF44 | 40A Power Supply

High-Capacity Power Delivery for SIMATIC S5 Systems

The 6ES5955-3LF44 power supply module provides robust and reliable DC power for SIMATIC S5-135U and S5-155U central controllers and EU 185U expansion units . This module accepts a wide input voltage range of 120/230 V AC at 50/60 Hz, making it suitable for global deployment. Moreover, this power supply delivers a substantial 40 A at 5 V DC, ensuring stable operation for densely populated racks .

Technical Specifications

Parameter	Specification
Manufacturer	Siemens
Product Line	SIMATIC S5
Model	6ES5955-3LF44
Module Type	Power Supply Module
Compatibility	S5-135U, S5-155U Controllers, EU 185U
Input Voltage	120/230 V AC
Input Frequency	50/60 Hz
Output Voltage	5 V DC
Output Current	40 A @ 5V
Power Output	200 W
Weight	10 kg
Dimensions (L x W x H)	70 x 50 x 10 cm
Protection Class	IP20
Certifications	UL (E143289) , CE
Product Status	Legacy / Obsolete

Output Specifications and System Compatibility

The 6ES5955-3LF44 delivers a high 40 A output on the 5 V DC rail, making it suitable for powering densely populated S5 racks with multiple I/O modules and communication processors. It integrates seamlessly into S5-135U and S5-155U systems . Furthermore, this module includes UL certification under file E143289, confirming its compliance with international safety standards .

Physical Characteristics and Installation

This module weighs approximately 10 kg and features substantial dimensions of 70 x 50 x 10 cm . Its robust construction withstands demanding industrial environments. The module’s IP20 protection rating provides basic protection against solid objects, making it suitable for installation within control cabinets. Users can easily install or replace the unit during maintenance operations.

Product Status and Support

Siemens has discontinued the 6ES5955-3LF44 as part of the legacy SIMATIC S5 lifecycle. Despite this, the module remains available through various industrial automation distributors offering new old stock or refurbished units with warranty coverage . Users should consider migration paths to newer S7 platforms for new installations.