GE IS200EGDMH1ADE – Exciter Ground Detector Module

Specifications

Functional Description

The IS200EGDMH1ADE is an Exciter Ground Detector Module manufactured by General Electric as part of the EX2100 Series for use in GE Excitation Control Systems. This double-slot, double-height (6U) form factor board installs in the Exciter Power Backplane rack (EPBP).

Its primary function is to detect leakage resistance between any point in the generator field circuit and ground—on either the AC or DC side. Simplex systems use one EGDM, while redundant systems use three modules.

System Integration

• The EXAM (attenuator module) senses voltage across the ground sense resistor and sends signals to the EGDM(s) via a nine-conductor cable. The EXAM is mounted in the High Voltage Module located in the Auxiliary Panel.

• In redundant systems, the three EGDM boards are designated as Controller (C), Master 1 (M1), and Master 2 (M2). Configuration is determined by program pins on the P2 connector.

• The DSPX module communicates the active master status via fiber-optic links to the Controller EGDM.

• When M2 is the driver, Controller powers the relay in the Attenuator Module; otherwise, it remains unpowered for M1.

• The active master receives an oscillator signal from the DSPX, generating a ±50 V square wave to the EXAM module and applied to the Sense Resistor.

Core Functions

• The signal conditioner receives a 10:1 attenuated differential signal from the Sense Resistor in the EXAM module.

• It uses a unity gain differential amplifier with a high common-mode rejection ratio, followed by a voltage-controlled oscillator (VCO) acting as an A-to-D converter.

• The VCO output feeds a fiber optic transmitter.

• The signal conditioner is powered by an isolated supply to ensure personnel and equipment safety given the high common-mode voltage.

• The signal conditioner can ground the bridge side of the Sense Resistor on command to measure power amplifier output levels.

• The Controller section determines the master module and generates a test command signal triggered by the oscillator signal transitions, with a duration of 250 ms, retriggerable on each transition.

Availability and Support

WOC maintains the largest stock of GE Excitation Control System replacement parts, including new, unused, and rebuilt modules, all backed by warranty. Our expert team is available 24/7 to support your OEM needs and assist with any automation requirements.

For pricing and availability, please contact us by phone or email.