Siemens 6ES5188-3UA22 135U/155U Central Rack – Heavy-Duty 40A Backplane Power for Large-Scale S5 Systems

Siemens 6ES5188-3UA22 135U/155U Central Rack – Heavy-Duty 40A Backplane Power for Large-Scale S5 Systems - Image 2

Siemens 6ES5188-3UA22 135U/155U Central Rack – Heavy-Duty 40A Backplane Power for Large-Scale S5 Systems

Product Overview

The 6ES5188-3UA22 is a SIMATIC S5-135U/155U central controller rack manufactured by Siemens, engineered as the mechanical and electrical backbone for large-scale, high-density S5 automation systems. According to Siemens’ official S5-135U/155U system manual, the 6ES5188-3UA22 belongs to the family of S5-135U/155U central controllers that consist of a robust sheet-steel housing with an integrated backplane bus, a powerful internal power supply unit with cooling fans, and 21 module slots for accepting CPUs, I/O modules, communication processors, and function modules. The distinctive configuration of the 6ES5188-3UA22 is its 120/230 V AC input power supply that delivers a hefty 5 V DC at 40 A to the backplane, making it the highest-current variant in the 6ES5188-3UAxx series.

As confirmed by Siemens industry documentation, the 6ES5188-3UA22 is supplied without a CPU, without a backup battery, and without a printed manual — giving system integrators full freedom to populate the 21 slots with the exact mix of S5-135U/155U-compatible modules their application demands. The integrated power supply accepts a wide-range 120/230 V AC mains input and converts it to the 5 V DC logic rail that powers all inserted modules, while the built-in fan assembly ensures forced-air cooling even when the rack is fully loaded with high-power digital and analog I/O. Physically, the 6ES5188-3UA22 measures 310 mm in height, 430 mm in width, and 470 mm in depth, weighing approximately 11 kg as a bare chassis (19.4 kg packed for shipping).

Siemens has officially placed the 6ES5188-3UA22 at the end of its product lifecycle as of October 1, 2022, with formal support services concluded. However, because the SIMATIC S5 platform continues to govern countless power plants, steel mills, chemical facilities, and manufacturing lines worldwide, the 6ES5188-3UA22 remains one of the most sought-after MRO spare parts in the industrial automation market. Professional surplus suppliers and specialized repair houses now offer refurbished, repaired, or new-surplus 6ES5188-3UA22 units, each fully bench-tested to verify backplane continuity, 5 V DC 40 A power-supply output under load, and fan operation — ensuring that legacy S5-135U/155U installations can continue running reliably for decades beyond Siemens’ original support window.

Description

Technical Specifications

Parameter	Value
Product Model	6ES5188-3UA22
Manufacturer	Siemens AG
Product Type	SIMATIC S5-135U/155U Central Controller Rack
Product Family	SIMATIC S5 (S5-188U / S5-135U / S5-155U series)
Module Slots	21 slots for CPUs, I/O, communication, and function modules
Power Supply Input	120 / 230 V AC
Power Supply Output	5 V DC, 40 A (integrated PSU)
CPU Included	No (user-supplied, 135U/155U compatible)
Backup Battery Included	No
Cooling Method	Forced air via integrated fan assembly
Mounting Method	Cabinet mounting via rear mounting brackets
Protection Rating	IP20 (indoor control cabinet)
Operating Temperature	0 °C to +60 °C (ambient, with adequate ventilation)
Dimensions (H × W × D)	310 × 430 × 470 mm
Net Weight	Approx. 11 kg (bare chassis)
Shipping Weight	Approx. 19.4 kg
Compatible Modules	Full SIMATIC S5-135U/155U module range
Backplane Bus	Integrated S5 system bus for data, address, and power distribution
Lifecycle Status	Discontinued since 01-Oct-2022, support concluded; repairable
Commodity Code	85371091
Country of Origin	Germany

Main Features and Advantages

High-capacity 40 A backplane power: The defining strength of the 6ES5188-3UA22 is its integrated 120/230 V AC to 5 V DC 40 A power supply — the most powerful variant in the 6ES5188-3UAxx family. This 40 A rail comfortably drives a fully populated 21-slot configuration with multiple high-density digital I/O cards, analog input/output modules, communication processors, and function modules simultaneously. The wide-range AC input (120 V or 230 V) eliminates the need for a separate AC/DC conversion stage, while the 6ES5188-3UA22‘s integrated PSU is purpose-built for the sustained current draw profiles typical of large S5-135U/155U installations.

Twenty-one module slots for maximum scalability: With 21 available slots, the 6ES5188-3UA22 provides exceptional architectural flexibility. Slot 1 is reserved for the power supply interface, Slot 2 hosts the CPU (such as 6ES5175 or 6ES5176 series), and Slots 3–21 are open for a tailored combination of digital I/O, analog I/O, communication processors (CP), interface modules (IM), and function modules (FM). This generous capacity makes the 6ES5188-3UA22 ideal for complex machine control, large process automation skids, and centralized I/O hubs that would require multiple smaller racks in competing platforms.

Industrial-grade mechanical design: The 6ES5188-3UA22 features a rigid metal housing with a cable duct, sectional rails for individually locking modules, a locking bar, and an optional filter sub-drawer — details that reflect Siemens’ decades of industrial enclosure engineering. The integrated fan assembly actively cools the installed modules, while the accessible battery compartment (though no battery is shipped) allows field technicians to add a rechargeable backup cell for CPU memory retention. The 6ES5188-3UA22 mounts securely to the rear of a control cabinet via robust mounting brackets, and its IP20 rating ensures safe operation in standard industrial enclosures.

Seamless compatibility with the S5-135U/155U ecosystem: Every module designed for the SIMATIC S5-135U/155U family plugs directly into the 6ES5188-3UA22 backplane without adapters or jumpers. Digital I/O modules (6ES532x, 6ES542x, 6ES543x, 6ES544x, 6ES545x, 6ES546x, 6ES547x, 6ES548x, 6ES549x series), analog I/O modules (6ES546x, 6ES547x, 6ES548x, 6ES549x, 6ES598x series), communication processors (6ES551x, 6ES552x, 6ES553x series), and interface modules (6ES554x, 6ES556x series) all seat natively in the 6ES5188-3UA22. This universal compatibility protects the client’s existing module inventory and dramatically simplifies system expansion or reconfiguration.

End-of-life but fully repairable: While Siemens has concluded official support for the 6ES5188-3UA22 as of October 2022, the unit’s straightforward electromechanical architecture means it remains eminently repairable. Specialized automation service providers can refurbish the 6ES5188-3UA22 — replacing capacitors, servicing the fan assembly, verifying backplane bus integrity, and load-testing the 5 V DC 40 A power supply — and return it to like-new performance with a 12- to 24-month warranty. This repairability, combined with the availability of new-surplus stock, makes the 6ES5188-3UA22 a sustainable and cost-effective choice for extending the life of mission-critical S5 installations far beyond the original manufacturer’s support horizon.