The Siemens 6ES5902-3SA12 is a power supply module belonging to the legacy SIMATIC S5 series, designed to provide stable electrical power to S5 PLC system components. Below is the detailed information compiled from historical technical archives and industrial documentation:
- Product Series: SIMATIC S5 (compatible with S5-115U/135U/155U modular PLC systems, the most common configurations for the S5 series)
- Module Type: Switch-mode power supply (SMPS) module for S5 PLC racks
- Product Status: Obsolete/DiscontinuedAs Siemens has phased out the entire SIMATIC S5 product line, this power supply module is no longer in production. Spare parts and official technical support are limited, with modern alternatives found in the SIMATIC S7 series or third-party legacy component suppliers.
- Dimensions (W×H×D): ~40 mm × 130 mm × 180 mm (matches the standard S5 module form factor for rack mounting)
- Weight: Approximately 0.8 kg (heavier than I/O modules due to internal power conversion components)
- Operating Temperature: 0°C to +60°C (non-condensing, suitable for control cabinet environments)
- Storage Temperature: -20°C to +80°C
- Protection Rating: IP20 (intended for indoor, panel-mounted use only; not waterproof or dustproof for field installation)
- Mounting: Installed in the leftmost slot of the S5 PLC rack (standard position for S5 power supply modules) via the backplane bus connector; secured with a locking clip to prevent disconnection.
As the primary power source for S5 modular PLC systems, the 6ES5902-3SA12 converts alternating current (120/230V AC) from the mains supply into regulated direct current (5V DC). Its key roles include:
- Supplying stable 5V DC power to the S5 backplane bus, which distributes power to all installed modules (CPU, digital/analog I/O, communication modules).
- Protecting the PLC system from electrical faults (e.g., overloads, short circuits) via built-in safety mechanisms, reducing downtime and component damage.
It was widely used in industrial facilities (e.g., manufacturing plants, power stations, process control systems) to power S5 PLCs during the series’ operational peak (1980s–2000s).
- Replacement: For maintenance of legacy S5 systems, Siemens recommends third-party compatible power supplies or migrating to the SIMATIC S7 series with equivalent power modules (e.g., 6ES7 307-1KA02-0AA0 for S7-300).
- Legacy Support: Historical technical manuals (e.g., "SIMATIC S5 Power Supply Modules") can be requested from Siemens’ legacy documentation archive for wiring diagrams and troubleshooting guidance.
For specific maintenance or replacement queries, contact Siemens Industrial Support or specialized legacy automation component suppliers.
