Siemens 6ES5951-7LD21 Programmable Logic Controller Module

Siemens 6ES5951-7LD21 is a PS951 power supply module for the SIMATIC S5 family, designed to power S5-115U/H controllers without a backup battery. It accepts 120/230 V AC input and provides a 5 V DC output with a current rating of 7 A or 15 A, depending on the variant, serving as the 951 series supply for legacy S5 installations. This unit is offered as a spare part for the S5-115U/H models and, according to distributors, carries a Romanian origin. Its physical dimensions are approximately 195 mm in height, 310 mm in length, and 65 mm in width, with a weight around 1.86 kg. The product is described in catalogs and listings as obsolete or end-of-life, yet it remains available from surplus or refurbished-stock suppliers for legacy Siemens SIMATIC S5 systems.