Eaton Cutler Hammer MP3000 Ampgard Protective Relay 66D2032G51

The Eaton Cutler Hammer MP3000 Ampgard Protective Relay (66D2032G51)

is a microprocessor-based motor protection relay designed for medium-voltage motor control systems, particularly within Eaton Ampgard motor control centers.

This relay is part of the MP-3000 series, which provides advanced protection and monitoring for industrial motors. It continuously analyzes current waveforms and operating conditions to protect motors from damage due to overload, faults, and abnormal conditions.

The unit is designed for panel mounting and typically operates with 120/240 VAC control power and 5A current transformer inputs, making it suitable for integration into standard industrial control panels.

Key protection functions include:

• Thermal overload protection (motor heating model)
• Instantaneous and time-delayed overcurrent protection
• Ground fault protection
• Phase imbalance and negative sequence current monitoring

The relay also includes motor start control logic, allowing it to limit the number of starts within a defined period and prevent overheating during repeated starts.

Within Ampgard medium-voltage starters, the MP3000 plays a critical role in ensuring coordinated protection between fuses, contactors, and motors, improving system reliability and safety.

Although discontinued, it remains widely used in legacy systems and is often replaced by newer Eaton EMR series relays.

? Key Features

• Microprocessor-based motor protection relay
• Designed for Ampgard medium-voltage motor control systems
• Thermal overload protection with motor heating model
• Overcurrent and ground fault protection
• Phase imbalance and negative sequence detection
• Motor start control and restart timing logic
• Panel-mounted design with compact housing
• Communication capability for monitoring and diagnostics

⚙️ Applications

• Medium-voltage motor control centers (MCC)
• Industrial plants and manufacturing systems
• Oil & gas and petrochemical industries
• Power generation and utilities
• Large motor protection in heavy industries

? Notes

• Part Number: 66D2032G51
• Series: MP3000
• Manufacturer: Eaton (Cutler-Hammer)
• Designed for Ampgard motor starters
• Status: Discontinued (replaced by newer EMR series)
• Commonly available as surplus or refurbished units

? Simple Explanation

? This device protects large industrial motors by monitoring current and stopping the motor if something goes wrong (like overload, fault, or overheating), preventing serious damage.