Product Overview
The Siemens 6ES5135-3KA12 is a passive PLC rack or chassis designed for the SIMATIC S5 series of programmable logic controllers. This rack serves as the foundational hardware platform for S5-135U and S5-155U systems, providing the mechanical support and electrical backplane connections for all system modules. As the product name indicates, the 6ES5135-3KA12 does not include a power supply, requiring a separate S5 power supply module such as the 6ES5955 series to be installed in the designated slot .
As a central component of the SIMATIC S5 family, the Siemens 6ES5135-3KA12 provides the structural backbone for building complete control systems. It houses the CPU module, power supply, and a wide variety of I/O modules, communication processors, and function modules. According to technical specifications from multiple suppliers, the Siemens 6ES5135-3KA12 offers 12 module slots with 25.4 mm spacing, accommodating the full range of S5-135U modules including CPUs, I/O cards, and communication processors . The integrated multi-layer passive printed circuit board (PCB) backplane supports parallel I/O and communication buses, enabling seamless data exchange between modules at high speeds . While some industry sources indicate that the 6ES5135-3KA12 may also be compatible with S5-115U systems , the prevailing consensus identifies it as the chassis for S5-135U and S5-155U platforms .
Technical Specifications
| Parameter Name | Value |
|---|---|
| Product Model | 6ES5135-3KA12 |
| Manufacturer | Siemens |
| Product Type | PLC Rack / Chassis (Without Power Supply) |
| Series | SIMATIC S5 |
| Compatible Systems | S5-135U, S5-155U (S5-115U compatibility reported by some sources) |
| Number of Module Slots | 12 slots (25.4mm spacing) |
| Backplane Type | Passive multi-layer PCB with parallel I/O and communication buses |
| Module Connectors | 48-pin DIN connectors per slot |
| Mounting Format | 19-inch rack mountable |
| Dimensions | Approx. 482mm (19″) width x 267mm (6U) height x 245mm depth |
| Weight | Approx. 4.8 kg (empty) |
| Maximum Module Load | 15 kg total for installed modules |
| Cooling Method | Natural convection (no fan required) |
| Chassis Material | Powder-coated steel with M4 grounding stud |
| Operating Temperature | 0°C to +60°C |
| Storage Temperature | -40°C to +70°C |
| Degree of Protection | IP20 |
Main Features and Advantages
The Siemens 6ES5135-3KA12 offers a robust and stable foundation for legacy S5 automation systems. Its 19-inch rack-mount design conforms to standard industrial cabinet dimensions, allowing straightforward installation into existing infrastructure. The Siemens 6ES5135-3KA12 features a passive multi-layer PCB backplane that separates I/O and communication buses for improved performance . This design ensures reliable signal integrity and data throughput even as modules are installed, removed, or reconfigured.
The modularity of the 6ES5135-3KA12 provides significant flexibility in system configuration. The CPU can be installed in any of the 12 slots, though slot 1 is the conventional location, allowing for customized system layouts based on specific application requirements . The 48-pin DIN connectors for each module slot ensure secure and reliable electrical connections, while the 25.4 mm slot spacing accommodates all standard S5-135U modules . Despite its age, the Siemens 6ES5135-3KA12 remains a structurally robust solution.
As an empty rack, the Siemens 6ES5135-3KA12 requires a separate power supply module to be installed in a designated slot. This external power supply model (such as the 6ES5955 series) provides flexibility in choosing the correct power rating for the specific application. The chassis design includes an M4 grounding stud on the rear panel for proper earthing, enhancing electrical safety and noise immunity . Additionally, the natural convection cooling design eliminates the need for fans, reducing maintenance requirements and potential points of failure.
