6ES5955-3LF12 belongs to classic Siemens SIMATIC S5 PLC family, rack mounted module for S5-135U/150U/155U chassis. Input voltage 115/230V AC selectable, output 5V DC, max 40A. It supplies power to all modules on the S5 backplane, including CPU, digital and analog I/O cards.

It supports backup battery installation to retain RAM program and data during mains power failure. Integrated protection functions: overcurrent, short circuit, overvoltage and undervoltage protection. LED indicators display power status and fault alarms for fast on-site troubleshooting. Protection class IP20, operating temperature 0~60℃.

6ES5955-3LF12 is obsolete Siemens S5 power supply spare part. Many old automation machines still run S5-135U/155U control systems. When the original module fails, replacement with identical 6ES5955-3LF12 can reuse rack, backplane wiring and existing user program. Technicians install the module, perform power-on test and check backplane voltage, so the whole PLC control system resumes operation and reduces downtime.

Before shipment, every 6ES5955-3LF12 undergoes comprehensive functional inspection including power-on self-test, 5V DC output test, short-circuit protection test and backplane compatibility verification. All products come with 12-month warranty. Our automation technical team provides remote support for installation, wiring guidance and fault diagnosis. Fast global shipping available for urgent maintenance orders.

For automation maintenance engineers and system integrators, 6ES5955-3LF12 is reliable spare rack power supply module for legacy Siemens SIMATIC S5 control systems. It restores stable power supply for CPU and I/O modules, extends service life of automation assets and avoids whole control system renovation.