Introduction

The FGD-2 Field Ground Detector Module is a transducer that continuously

monitors the resistance of the field circuit of a synchronous machine with

respect to ground. It applies a fixed voltage with respect to ground which

causes a small leakage current to flow. The FGD-2 provides a low voltage

output signal proportional to the leakage current.

The voltage output is measured by a compatible product and used for

field ground protection. Two versions of the FGD-2 are available. A low-

voltage version, rated for 800 Vdc maximum generator field voltage, is

provided for brush or brushless exciter systems. A high-voltage version,

rated for 1.750 Vdc generator field voltage, is provided for static exciter

systems.

The metal enclosure of the FGD-2 offers electric shock protection from

incidental contact. A compatible footprint and identical functionality

make for simple replacement of a Field Ground Detector (FGD) with the

FGD-2.