INTRODUCTION

The DXCB-2 De-Excitation/Crowbar Module protects the generator

field and exciter circuits by providing a low impedance path for

currents that would otherwise cause excessively high transient

voltage or damaging arcs. A DXCB-2 module can be operated in

one of two modes: de-excitation (DX) or crowbar (CB).

In DX mode, the DXCB-2 module provides a path for the generator

field current when its field breaker is opening or when the normal

path is not available.

In CB mode, the DXCB-2 module provides a low-resistance path

for large positive voltages across the generator field and exciter

bridge. Generator pole-slip is one source of high voltage.

The enclosure of the DXCB-2 offers electric shock protection from

incidental contact. An identical footprint and functional compatibility

make for simple replacement of a DXCB with a DXCB-2.