GE DS3800HARA EAROM Card

The GE DS3800HARA is a specialized circuit board known as an EAROM Card (Electrically Alterable Read-Only Memory), used in the GE Speedtronic Mark IV series of turbine and generator control systems. It is a legacy part, no longer in production, and is primarily found on the surplus and refurbished markets for the maintenance of older control systems.

Function and Purpose

The primary function of the DS3800HARA is to provide non-volatile memory storage for critical system parameters and configuration data. Unlike conventional volatile memory (RAM), which loses its data when power is turned off, an EAROM retains its information. This is crucial in an industrial control system for several reasons:

• Parameter Storage: It stores essential operating parameters for the turbine, such as speed setpoints, temperature limits, and control constants. These values must persist even during power outages or system shutdowns.
• Configuration Data: It holds configuration data that defines the specific setup of the turbine and its control system. This ensures that the system starts up correctly and operates according to the specific application.
• Data Logging: It can be used for logging critical events or fault data, providing a record for later analysis by maintenance personnel.
• Firmware: While its primary role is data storage, some versions may also contain firmware that governs the functionality of a specific module.

Technical and Design Features

The DS3800HARA is a robust, industrial-grade circuit board designed to operate in a demanding environment.

• Legacy Part: The “DS3800” prefix indicates that it belongs to the legacy Mark IV series, a pioneering control system for gas and steam turbines in the late 1980s.
• EAROM Chip: The board is populated with an EAROM chip, which is the core component for non-volatile memory storage.
• Connectors: It has two 34-pin connectors that allow it to interface with other boards in the control rack.
• Jumpers: The board includes several jumpers that allow technicians to configure its operational settings to match the specific requirements of a given application.
• Retention Levers: The card features retention levers for secure installation in the drive system, preventing it from coming loose due to vibration.

Applications and Importance

The DS3800HARA is a fundamental component of the GE Mark IV system. Its importance lies in its ability to securely and reliably store critical data that the system needs to operate. Without this board, the control system would be unable to retain its configuration and operating parameters, making it impossible to safely and efficiently operate the turbine.