Operation Manual

GENERATOR ASSEMBLY INFORMATION

EXCITER TYPE GENERATOR

The exciter pole pieces contain residual magnetism, which sets up lines of force across the air

gap to the exciter armature. When the exciter begins to rotate a voltage is induced and current flow is

initiated in the exciter armature AC windings. This voltage is fed to the rotating rectifier assembly,

rectified and fed to the alternator field, which sets up lines of force across the air gap to the alternator

stator windings and to the output circuit.

A static voltage regulator is connected to the generator output. The regulator will rectify part of

the output voltage to provide a DC voltage to the exciter field coils. This will increase the density of the

lines of force in the exciter, increasing the voltage induced into the exciter armature windings, and

therefore, to the rotating rectifiers. The rotating rectifier output will be increased which will increase the

alternator field strength and generator output will build up its rated voltage. Adjustment of the generator

output to the rated voltage level is accomplished by controlling the current fed to the exciter field coils.

Regulation is automatic with the static type voltage regulator. An additional voltage adjustment range is

provided if desired by turning the Voltage Adjust Rheostat.

ELECTRONIC VOLTAGE REGULATION

Electronic Voltage Regulator (EVR) also referred to, as an Automatic Voltage Regulator (AVR)

is a very reliable device, which uses solid-state electronics to maintain voltage accuracy at ±2% of the

regulated voltage. The Voltage Regulator is designed to automatically regulate and maintain the

generated AC voltage through out the load range that is from no load to full load.

EXCITER FIELD COIL VOLTAGE SOURCE

Field coil DC voltage is obtained by rectifying the voltage from the phase to neutral line of the

generator output, or either appropriate terminal to provide the needed voltage reference.

The rectifier bridge is an internal part of the static regulator. The static regulator senses a change

in the generator output and automatically regulates current flow in the exciter field coil circuit to

increase or decrease the exciter field strength. An adjustable rheostat sized to be compatible with

the regulator is used to provide adjustment of the regulator sensing circuit.