ABB 500CPU03 1HDF700003R5122 | Central Processing Unit Module

Technical Specifications

Specification caution: Current secondary listings contain major contradictions. Some incorrectly classify this part as an ABB AC500-eCo PLC and publish modern PLC specifications such as 24 VDC supply, Ethernet, RS-485, 1 GB RAM, and DIN-rail mounting. Those claims are not consistent with the ABB 500-series documentation that lists 500CPU03 alongside the other 500-series protection/control modules.

Product Introduction

The ABB 500CPU03 1HDF700003R5122 is a processor module associated with ABB’s legacy 500-series control architecture. Its primary role is to provide the central processing function for the system, executing the configured application and coordinating data exchange with the associated control, I/O, and communication modules.

500CPU03 1HDF700003R5122

The ABB 500CPU03 should not be confused with a modern ABB AC500 PLC CPU. Several current reseller pages make that classification, but their specifications are internally inconsistent and are not supported by the stronger evidence available for this exact part number. ABB’s indexed material places 500CPU03 1HDF700003R5122 in the same family of legacy hardware as 500TRM02, 500SCM01, 500BOM01, and 500PB101.

The ABB 1HDF700003R5122 designation is especially important when sourcing a replacement because the 500-series contains numerous specialized modules. A CPU with a similar physical appearance or the same 500-series designation is not automatically interchangeable.

For an installed system, the processor should be considered together with the complete rack architecture, power supply, communication modules, terminal/interface hardware, application configuration, and firmware. The exact system in which a particular 500CPU03 is installed should be established before replacement.

Main Features & Field Considerations

Central processing

The 500CPU03 provides the processing layer of the associated ABB control system. A failure can therefore affect system-wide operation rather than a single field signal.

500-series system integration

ABB’s indexed material places the CPU alongside other dedicated 500-series components, including the 500PB101 communication module, 500TRM02, 500SCM01, and 500BOM01.

Legacy hardware

This is not a component I would treat as a generic PLC CPU. Its replacement needs to be based on the original system architecture and application configuration.

Replacement checks

Before replacing an ABB 500CPU03 1HDF700003R5122, verify:

• Exact model: 500CPU03
• Complete ordering number: 1HDF700003R5122
• Hardware revision
• Installed rack
• Associated power-supply module
• Communication modules
• I/O modules
• Terminal/interface modules
• Application configuration
• Firmware/software revision
• Existing parameter backup

Commissioning consideration

If the existing CPU is still operational, capture the system configuration and relevant parameters before removing it. A replacement processor may be electrically correct but still require the original application/configuration data before the system can return to service.

Typical Applications

The ABB 500CPU03 is associated with legacy ABB control architectures and can be encountered in applications involving:

• Substation control
• Protection-system control
• Industrial automation
• Power-system automation
• Distributed control architectures
• Legacy ABB 500-series installations

Procurement Note

For ABB 500CPU03 1HDF700003R5122, I recommend using the complete 500CPU03 + 1HDF700003R5122 identification rather than accepting a generic “AC500 CPU” description.

The exact part number is independently indexed in ABB-related documentation, while several current commercial listings provide conflicting and clearly modernized specifications.

For a replacement, the critical checks are exact article number, hardware revision, system/rack configuration, firmware, and application data. I would not publish definitive CPU speed, memory capacity, Ethernet ports, or 24 VDC supply specifications for this exact unit without an ABB source or the original nameplate.