Executive Summary
The Siemens 6ES7138-4CA01-0AA0 is a PM-E (Power Module Extended) power supply module within the SIMATIC ET 200S distributed I/O system family. Engineered specifically for industrial automation applications, this compact 15mm-wide module provides 24V DC load voltage with integrated diagnostic capabilities for enhanced system reliability. With a maximum current carrying capacity of 10A up to 60°C, comprehensive diagnostic indicators (PWR and SF LEDs), and galvanic isolation between load voltage and backplane bus, the module represents a critical component for modern distributed control systems in manufacturing, process automation, and machine building.
Technical Specifications Matrix
| Parameter | Specification | Standard/Compliance | Notes |
|---|---|---|---|
| Module Type | PM-E Power Module | Siemens ET 200S Series | With diagnostic capabilities |
| Article Number | 6ES7138-4CA01-0AA0 | Siemens SIMATIC DP | Alternate: 6ES7 138-4CA01-0AA0 |
| Rated Load Voltage (L+) | 24 V DC | IEC 61131-2 | Operating range: 20.4V to 28.8V DC |
| Current Carrying Capacity | 10 A (max at 60°C) | IEC 60947-1 | Derating above 60°C ambient temperature |
| Input Current (without load) | ≤ 4 mA | – | From load voltage L+ |
| Power Loss | 0.1 W (typical) | – | Thermal dissipation |
| Short-circuit Protection | External required | – | External circuit breaker, tripping characteristic C |
| Reverse Polarity Protection | Yes | – | Integrated protection circuit |
| Potential Separation | Primary/Secondary | IEC 61131-2 | Between rated load voltage and backplane bus |
| Isolation Test Voltage | 500 V DC | IEC 61131-2 | Between load voltage and backplane bus |
| Diagnostic Functions | Missing load voltage detection | – | Enabled/disabled via parameter |
| Diagnostic LEDs | PWR (green), SF (red) | – | Status indication |
| Module Width | 15 mm | – | Mounting dimension |
| Dimensions (H×W×D) | 81 × 15 × 52 mm | IEC 60068 | Height: 81mm, Width: 15mm, Depth: 52mm |
| Weight | Approx. 35 g | – | Net weight |
| Ambient Temperature | -10°C to +40°C | IEC 60068-2-1 | Operation range |
| Storage Temperature | -20°C to +60°C | IEC 60068-2-14 | Non-operating conditions |
| Relative Humidity | 95% max (non-condensing) | IEC 60068-2-3 | At 25°C |
| Vibration Resistance | 10-57 Hz: 0.075 mm amplitude | IEC 60068-2-6 | 57-150 Hz: 1g acceleration |
| Shock Resistance | 15g, 11ms duration | IEC 60068-2-27 | Half-sine wave |
| EMC Compliance | EN 61000-6-2, EN 61000-6-4 | EU EMC Directive | Industrial environment immunity/emission |
| Safety Standards | EN 61131-2, UL 508 | – | Industrial control equipment |
| Certifications | CE, UL Listed, cUL Listed | – | Market approvals |
| Country of Origin | Germany | – | Manufacturing location |
| Product Phase-out | Started 10.01.2020 | Siemens Product Lifecycle | Still available through distribution channels |
Functional Architecture
Power Supply and Distribution
The PM-E module serves as the primary 24V DC power source for ET 200S I/O modules:
– Load Voltage Generation: Converts incoming 24V DC supply to regulated voltage for connected modules
– Current Limiting: 10A maximum continuous current with thermal protection
– Galvanic Isolation: 500V DC isolation between power circuits and backplane bus prevents ground loops
Diagnostic Capabilities
Integrated monitoring features enhance system maintainability:
– PWR LED (Green): Indicates presence of rated load voltage (24V DC)
– SF LED (Red): Signals group error condition
– Missing Load Voltage Detection: Programmable diagnostic interrupt generation
– Parameter-based Configuration: 3-byte parameter area for diagnostic settings
Compatibility Analysis
ET 200S System Integration
The 6ES7138-4CA01-0AA0 module is designed for seamless integration with:
– ET 200S Interface Modules: IM151-1 STANDARD, IM151-1 HIGH FEATURE, IM151-1 FO STANDARD
– Digital I/O Modules: 2DI, 4DI, 8DI, 2DO, 4DO, 8DO modules (standard and high feature variants)
– Analog I/O Modules: 2AI, 4AI, 2AO, 4AO modules with various signal ranges
– Technology Modules: TM-E, TM-P modules for specialized functions
– Communication Modules: PROFIBUS DP, PROFINET IO interface modules
Terminal Module Compatibility
The power module connects to terminal modules with automatic coding:
– TM-E Terminal Modules: For electronic modules with spring or screw terminals
– TM-P Terminal Modules: For power modules requiring higher current capacity
– Automatic Coding: Mechanical coding prevents incorrect module insertion
Fieldbus System Support
Compatible with major industrial communication protocols:
– PROFIBUS DP: Up to 12 Mbit/s transmission rate
– PROFINET IO: Real-time industrial Ethernet
– AS-Interface: Lower-level device networking
– Modbus TCP/IP: Open industrial Ethernet standard
Application Guidelines
Industrial Automation Scenarios
Machine Control Systems
- Packaging Machinery: Power supply for I/O modules controlling conveyors, fillers, sealers
- Assembly Lines: Distributed I/O power for robotic workstations, vision systems
- Material Handling: Crane controls, conveyor systems, automated storage/retrieval
Process Automation Installations
- Chemical Processing: Intrinsically safe zone power distribution (with appropriate barriers)
- Pharmaceutical Manufacturing: Clean room automation equipment
- Food & Beverage: Washdown-resistant control panels
Building Automation
- HVAC Systems: Control of fans, pumps, dampers, valves
- Lighting Control: Smart building energy management
- Access Control: Security system power distribution
Installation Procedures
Mechanical Installation
- Module Mounting: Insert into ET 200S assembly rail using plastic coding elements
- Terminal Connection: Attach to compatible TM-E terminal module
- Wiring: Connect 24V DC power supply to L+ and M terminals
- Grounding: Ensure proper protective earth connection
Electrical Configuration
- Power Supply Rating: Verify 24V DC source compliance with module specifications
- Current Capacity: Calculate total load current of connected I/O modules
- Protection Devices: Install external circuit breakers (tripping characteristic C)
- Cable Selection: Use appropriate wire gauge for 10A maximum current
Diagnostic Setup
- Parameter Configuration: Set diagnostic interrupt enable/disable via engineering software
- LED Monitoring: Establish visual inspection procedures for PWR and SF indicators
- Fault Response: Develop troubleshooting protocols for missing load voltage conditions
Maintenance Considerations
Preventive Maintenance
- Visual Inspection: Quarterly check of LED indicators and physical condition
- Connection Verification: Annual tightening of terminal screws
- Environmental Monitoring: Regular assessment of temperature and humidity conditions
Predictive Diagnostics
- Load Current Monitoring: Periodic measurement of actual current draw
- Voltage Stability: Check for voltage fluctuations during operation
- Thermal Performance: Monitor module temperature under full load conditions
Alternative Model Recommendations
Siemens ET 200S Power Module Family
PM-E DC24V without Diagnostics (6ES7138-4CB00-0AA0)
- Key Differences: No diagnostic LEDs or missing voltage detection
- Applications: Cost-sensitive installations where diagnostics are not critical
- Compatibility: Identical mechanical dimensions and electrical specifications
PM-E DC24/48V with Diagnostics (6ES7138-4CA10-0AA0)
- Enhanced Features: Dual voltage support (24V/48V DC)
- Applications: Mixed voltage systems requiring flexible power distribution
- Considerations: Requires compatible terminal modules for higher voltage
PM-D DC24V (6ES7138-4CD00-0AA0)
- Basic Power Module: No diagnostics, lower cost option
- Applications: Simple power distribution without monitoring requirements
- Limitations: Reduced functionality for critical process applications
Competitive Alternatives
Phoenix Contact INTERFACE Power Supply (2866792)
- Similar Specifications: 24V DC, 10A output, diagnostic capabilities
- Advantages: Broader compatibility with multi-vendor systems
- Considerations: Different form factor may require panel redesign
WAGO 750-603 Power Supply Module
- Fieldbus Independence: Direct DIN rail mounting without interface module
- Applications: Stand-alone power distribution in compact panels
- Integration: May require additional interface components for ET 200S systems
Allen-Bradley 1492-PA3 Power Supply
- Rockwell Ecosystem: Optimized for ControlLogix/CompactLogix platforms
- Applications: Brownfield installations with existing Allen-Bradley infrastructure
- Migration Considerations: Significant engineering effort for system conversion
Procurement Guidelines
Sourcing Considerations
Authorized Distribution Channels
- Siemens Direct: Official Siemens distributors and partners
- Industrial Automation Specialists: Companies with Siemens certification
- Online Marketplaces: Verified sellers with genuine product guarantees
Counterfeit Detection
- Packaging Verification: Authentic Siemens packaging with security features
- Product Markings: Laser-etched part numbers and manufacturing codes
- Documentation: Complete technical documentation in multiple languages
Technical Evaluation Criteria
Performance Parameters
- Load Capacity: Verify 10A continuous current at 60°C ambient temperature
- Diagnostic Functions: Confirm PWR/SF LED operation and missing voltage detection
- Isolation Rating: 500V DC between load voltage and backplane bus
Environmental Compliance
- Temperature Range: -10°C to +40°C operating, -20°C to +60°C storage
- Humidity Tolerance: 95% relative humidity non-condensing
- Vibration/Shock: Compliance with IEC 60068-2-6/27 standards
Total Cost of Ownership Analysis
Initial Investment
- Module Cost: $45-$65 USD depending on quantity and distribution channel
- Integration Cost: Engineering time for system design and configuration
- Accessories: Terminal modules, connectors, mounting hardware
Operational Expenses
- Energy Consumption: 0.1W power loss contributes to system efficiency
- Maintenance: Preventive inspection procedures and potential replacements
- Downtime Impact: Diagnostic features reduce troubleshooting time and production losses
Lifecycle Considerations
- Product Availability: Phase-out initiated 2020, consider long-term supply planning
- Technology Migration: Plan for eventual replacement with newer module families
- System Scalability: Power module’s role in future expansion scenarios
Conclusion
The Siemens 6ES7138-4CA01-0AA0 PM-E DC24V power module represents a critical component in modern industrial automation architectures, providing reliable 24V DC power distribution with comprehensive diagnostic capabilities for ET 200S distributed I/O systems. With its compact 15mm design, 10A current carrying capacity, and integrated monitoring features, the module supports enhanced system reliability and reduced maintenance requirements across diverse industrial applications.
For engineers designing or maintaining automation systems, understanding the module’s technical specifications, compatibility requirements, and application guidelines is essential for optimizing system performance and ensuring long-term operational efficiency. While the product has entered its phase-out cycle, it remains available through authorized channels and continues to serve as a reliable solution for existing and new installations requiring proven Siemens technology.
References
- Siemens AG. (2007). SIMATIC ET 200S PM-E DC24V Power Module (6ES7138-4CA01-0AA0) Device Manual. A5E01119955-02.
- International Electrotechnical Commission. (2016). IEC 61131-2: Programmable controllers – Part 2: Equipment requirements and tests.
- Siemens Industry Online Support. (2020). ET 200S Distributed I/O System Documentation. https://support.industry.siemens.com
- International Electrotechnical Commission. (2014). IEC 60947-1: Low-voltage switchgear and controlgear – Part 1: General rules.
- RS Components. (2024). Siemens PLC I/O Module 6ES7138-4CA01-0AA0 Product Datasheet. https://sg.rs-online.com/web/p/plc-accessories/6623561
- Classic Automation. (2025). SIEMENS 6ES7138-4CA01-0AA0 ET 200S PM-E DC 24V Technical Specifications. https://www.classicautomation.com/Part/6es7138-4ca01-0aa0
- Distributor Data Solutions. (2020). Siemens 6ES7138-4CA01-0AA0 Data Sheet. https://media.distributordatasolutions.com/siemenscomplete/2021q2/documents/1ecc6aa8c02e55abeaae868e465b1cd63ec351cc.pdf
- DoSupply.com. (2025). Siemens 6ES7138-4CA01-0AA0 Power Module Technical Specifications. https://www.dosupply.com/automation/siemens/simatic/6ES7138-4CA01-0AA0
- Siemens AG. (2020). SIMATIC ET 200S System Manual. https://support.automation.siemens.com/ww/view/zh/1144348
- International Electrotechnical Commission. (2012). IEC 60068-2-6: Environmental testing – Part 2-6: Tests – Test Fc: Vibration (sinusoidal).
- Underwriters Laboratories. (2018). UL 508: Industrial Control Equipment Standard.
- European Committee for Electrotechnical Standardization. (2016). EN 61000-6-2: Electromagnetic compatibility (EMC) – Part 6-2: Generic standards – Immunity standard for industrial environments.
- Siemens AG. (2019). Product Lifecycle Information for SIMATIC ET 200S Modules. https://support.industry.siemens.com/cs/products/6es7138-4ca01-0aa0
- Phoenix Contact. (2023). INTERFACE Power Supply Module 2866792 Technical Documentation.
- WAGO Corporation. (2024). 750-603 Power Supply Module Installation Guide.