Core Strengths
Comprehensive Generator Protection

Provides full-condition generator protection, including:

Stator differential protection

100% stator ground fault protection

Overexcitation protection

Loss of excitation (demagnetization)

Reverse power protection

Suitable for synchronous generators of various capacity levels, from industrial captive units to utility-scale generators

Accurate Condition Monitoring

Integrated 12 RTD inputs and 4 analog measurement channels

Real-time monitoring of stator temperature, bearing temperature, vibration, speed, and electrical parameters

Enables early fault detection and condition-based maintenance

Easy Maintenance & High Availability

Drawer-type modular design, allowing module replacement without system power-off

Independent H-module diagnostics, ensuring fast fault localization

Significantly reduces maintenance time and unplanned downtime

Flexible Communication & System Integration

Supports multiple communication protocols for local and remote monitoring

Easily integrates with SCADA systems, DCS platforms, and intelligent substation networks

Designed to meet modern digital power plant and substation communication requirements

Electrical & I/O Specifications
Rated Measurement Inputs

Current transformer (CT):

5 A phase CT secondary

Voltage transformer (VT):

System voltage configurable

RTD inputs:

12 channels (stator and bearing temperature measurement)

Voltage inputs:

4-channel VT voltage input

Digital I/O

Digital inputs:

7 configurable digital input channels

Relay outputs:

6 × Form-C relay outputs

Includes H-module hardwired trip circuits for high-speed fault isolation

Analog I/O

Analog inputs:

4-channel isolated 4–20 mA inputs (vibration, speed, auxiliary signals)

Analog outputs:

4-channel isolated 4–20 mA outputs (control commands and signal transmission)

Communication Interfaces

Maintenance interface:

RS-232 local maintenance port

Serial communication:

2 × RS-485 (supports Modbus RTU and DNP3.0)

Ethernet:

10Base-T Ethernet

Supports Modbus TCP

Typical Application Scenarios
Power Plants / Captive Power Plants

Acts as the main generator protection device, providing differential, overcurrent, overvoltage, and excitation-related protections

The H module enables rapid tripping during severe faults

Seamlessly interfaces with DCS and SCADA systems

Key Industrial Power Systems

Used in petrochemical, metallurgical, and other industrial sectors with on-site power generation

H-module architecture meets high-reliability and safety requirements, preventing fault propagation and production losses

Substations

Protects grid-connected synchronous generators

Supports fast fault clearance and continuous monitoring of generator and grid operating parameters

GE 489-P5-LO-A20-E-H｜Generator Management Relay｜