Siemens SITOP PSU100L modules in phase-out as of 10/2025

On May 27, 2025, under publication ID 109988599, Siemens announced the phase-out of the SITOP PSU100L series. Effective immediately, active marketing will be discontinued. As of October 2025, the product status will change to P.M400, initiating the manufacturer’s 10-year spare parts commitment. Full type discontinuation (P.M410) is scheduled for October 2026 after stock depletion.

The SITOP PSU100L is a series of modular, single-phase 24 V DC power supply units from Siemens. They are designed for basic industrial automation applications and are used in conjunction with PLC controllers as well as identification and communication modules. The term “modules” refers to the different variants within this series — specific models with their own power classes and input voltages.

Product Status Legend:

• P.M300: Delivery phase (new units regularly available)
• P.M400: Phase-out announcement (spare parts commitment starts)
• P.M410: Type discontinuation (only spare part orders possible)
• P.M490: Product discontinuation (spare part obligation ends)
• P.M500: End of product lifecycle (no deliveries or consultation available)

The transition from the Siemens SITOP PSU100L series to the Siemens SITOP PSU4200 series will require system modifications. Changes in dimensions, connection technology (push-in instead of screw terminals), and the number of output terminals will necessitate both mechanical and electrical adjustments. In many cases, the installation environment will also need to be adapted, as the temperature ranges are expanded and derating only takes effect at higher temperatures.

For purchasers, the switch to the Siemens SITOP PSU4200 will result in additional costs in the medium term due to conversions and adjustments. At the same time, procuring new spare parts for the SITOP PSU100L will become increasingly difficult and expensive over time as stock levels decline and prices rise. EICHLER will optimize cost-efficiency through professional repairs and tested refurbished devices.

EICHLER will continue to offer repairs for all discontinued Siemens SITOP PSU100L models in the long term. In parallel, a large inventory of refurbished replacement units will be maintained. This will allow technicians and maintenance personnel to ensure system availability even after October 2026. Purchasers will be able to preserve budgets, as costly new investments will not be immediately necessary.

Plant operators will gain planning security. Repairs will remain possible at short notice. Replacement units will be available even for fully discontinued Siemens SITOP PSU100L devices. Additionally, EICHLER will provide consulting support for planned conversions to the Siemens SITOP PSU4200 series. This will ensure that retrofitting can be carried out in both an economically and technically optimal way.

Conclusion: With Siemens discontinuing the SITOP PSU100L series starting in October 2025, many maintenance teams and purchasers will face an increased need for action. Thanks to EICHLER's services, supply will remain secured even after the type discontinuation.