Siemens

Siemens 6ES5188-3UA21 SIMATIC S5 Central Unit

SKU 6ES5188-3UA21

In stock
  • 12-month warranty
  • Free returns within 30 days

  • Manufacturer: Siemens

  • Product No.: 6ES5188-3UA21

  • Country of origin:Germany

  • Product Type: Central Units

  • Barcode: 85389091

  • Payment: T/T, Western Union

  • Weight: 19400g

  • Dimensions: 56.00cm x 43.00cm x 53.50cm

  • Shipping port: Xiamen

  • Warranty: 12 months

Description

The 6ES5188-3UA21 is a central rack assembly designed for the SIMATIC S5-135U and S5-155U programmable logic controller systems. This unit provides a robust foundation for high-performance automation tasks, featuring 21 slots for modular expansion and configuration. It is equipped with an integrated power supply capable of handling 230/115 V AC input, delivering a regulated 5 V, 40 A output to the backplane. Note that this unit is supplied without a CPU module and without documentation. As a central component in legacy SIMATIC S5 architectures, it serves as the primary mounting and power distribution base for processors, I/O modules, and communication modules in large-scale control applications.

Features

  • Large-Scale Expansion: Features 21 slots for extensive I/O and communication module installation.
  • Integrated Power: Built-in power supply unit with 230/115 V AC input and 5 V DC, 40 A output.
  • System Compatibility: Designed specifically for the high-end SIMATIC S5-135U and S5-155U range.
  • Modular Configuration: Provides the flexibility to insert various CPU types depending on specific control requirements.

Applications

  • Large-scale industrial process control
  • Retrofitting and maintenance of existing S5-135U/155U installations
  • Multi-axis machine tool control
  • Complex production line automation requiring high I/O density

Technical Specifications

Feature Specification
Manufacturer Siemens
Brand SIMATIC S5
Range S5-135
Model 6ES5188-3UA21
Product Phase Obsolete
Successor 6ES5188-3UA22
Slot Capacity 21 Slots
Supply Voltage 230/115 V AC
Output Power 5 V, 40 A
Weight 19.40 kg
Dimensions 56.00 x 43.00 x 53.50 cm
Commodity Code 85389091
Export Control (ECCN) N

Installation Guidelines

  • Mounting: Due to its weight (19.40 kg), ensure the rack is mounted to a high-strength industrial cabinet backplane capable of supporting the static load.
  • Ventilation: The high power output of this unit generates heat; ensure clear airflow paths through the rack and sufficient cabinet ventilation.
  • Wiring: Connect the AC supply according to local electrical codes, ensuring the ground connection is established to the cabinet common ground.
  • Module Insertion: Always power down the unit before inserting or removing CPU or I/O modules to prevent electrical arcing or damage to the backplane connectors.

FAQ

Does the 6ES5188-3UA21 include a CPU?
No, this unit is supplied without a CPU and without a manual.

What power does this rack provide to the backplane?
The integrated power supply provides 5 V DC at 40 A.

Is this compatible with the S5-155U system?
Yes, this central unit is designed for use in both S5-135U and S5-155U configurations.

What is the successor for this model?
The official successor model is the 6ES5188-3UA22.

View all FAQs →

6ES5188-3UA21
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Shipping & Returns

Global Express Shipping

  • Standard Delivery: 4–6 business days via DHL, FedEx, and UPS.
  • Express Dispatch: Same-day dispatch for in-stock orders placed before 2:00 PM (GMT+8).
  • Worldwide Coverage: Serving over 150 countries.

Returns & Warranty

  • 30-Day Guarantee: Returns accepted for in-stock products in original, factory-sealed packaging.
  • 12-Month Warranty: Every industrial component is backed by our technical warranty.
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Global Express Shipping

  • Standard Delivery: 4-6 Business Days via DHL, FedEx, and UPS.
  • Express Dispatch: Same-day dispatch for in-stock orders placed before 2:00 PM (GMT+8).
  • Worldwide Coverage: Serving over 150 countries, including rapid delivery to Saudi Arabia and UAE.

Returns & Warranty

  • 30-Day Guarantee: Returns accepted for in-stock products in original, factory-sealed packaging.
  • 12-Month Warranty: Every industrial component is backed by our professional technical warranty.

Orders are processed and delivered Monday-Friday (excluding public holidays).


For full eligibility, restocking fees, and international return details, please view our official Refund & Return Policy .

TECHNICAL SPECIFICATIONS

Color pattern
Greyish White
Country of origin
Germany
Power source
AC-powered DC Power

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