Description

The Siemens Simatic S5 6ES5 955-3NF42 is a high-capacity power supply module engineered for the S5-135U and S5-155U automation systems. This unit provides regulated DC power to central controllers and expansion subracks, ensuring stable operation for high-density PLC installations. By converting 24 VDC input into a robust 5 VDC output at 40 A, this module supports the demanding power requirements of large-scale industrial control architectures, including those found in power generation and chemical processing facilities.

Features

• Designed for S5-135U, S5-155U, and EU 185U subrack compatibility.
• Integrated pulse-width modulation (PWM) for stable voltage regulation under varying loads.
• Built-in protection features including overvoltage crowbar, thermal overload shutdown, and transient sag filtering.
• Dedicated interface for external backup battery support to ensure RAM data integrity.
• Engineered for high-temperature environments with integrated forced-air cooling channels.

Technical Specifications

Installation Guidelines

• Ensure the PLC rack is powered down before installing or removing the power supply module.
• Verify that the input voltage matches the 24 VDC specification before connection to prevent damage.
• Ensure the module is fully seated in the subrack to maintain proper backplane contact.
• Maintain clear airflow paths around the module to allow the integrated cooling system to function effectively.
• Use shielded cabling for power inputs to minimize EMI interference in high-noise industrial environments.
• Handle the unit using standard ESD precautions to protect internal solid-state components.

FAQ

Does this module support battery backup?

Yes, the 6ES5 955-3NF42 includes an interface for an external backup battery (typically the CA-6EW1000-7AA) to maintain RAM data during power loss.

What systems is this power supply compatible with?

This module is specifically designed for Siemens Simatic S5-135U and S5-155U central controllers, as well as the EU 185U expansion subracks.