GENERAL DESCRIPTION

The Basler XR2002 and XR2002F PMG Voltage Regulators provide the dc exciter field

regulation to PMG (Permanent Magnet Generator) equipped 50 or 60 Hz brushless generators.

The Regulator is available in two models:

XR2002: Standard (without a Voltage Limited Volts-per-Hertz characteristic).

XR2002F: With a Voltage Limited Volts-per-Hertz characteristic.

b. Input power may be provided by either a single-phase or a three-phase PMG, or optionally, it

may be supplied by the generator output.

TERMINALS 51.52.53. 54. AND 55 (and 56 on units S/N 1 through 236)

a. These terminals allow additional external accessories and modules to be combined with the

voltage regulator to expand the capabilities of the regulator. An internal jumper must be

connected to terminal 54 for normal regulator operation. An external jumper is normally

connected between terminals 53 and F+. This jumper may be replaced by an excitation

shutdown switch. No connection should be mad to terminals 51. 52. 55. or 56 unless so directed

by an accessory device instruction manual. Refer to Paragraph 2-5.

b. Note that on units with serial numbers 001 through 236. terminal 56 is used in lieu of terminal

55. On units with serial numbers 237 and higher, terminal 56 is not present and terminal 55 is

used for the external connections.

SAFETY

As with all electrical equipment, appropriate safety measures must be

taken when dealing with excitation equipment. High voltage is present

within the excitation cubicles; their magnitudes depend upon the

particular system. Opening the sources (e.g., disconnecting device 41)

does not completely disconnect the high voltages.

As long as the machine is still physically connected to the system, there

is a possibility that a safety hazard exists.

Every precaution must be taken when working at the excitation control

switchgear to ensure that all high voltages are isolated and avoided by

test personnel. In addition to the machine terminal voltage (460 Vac or

greater) at the excitation transformer, there may be other sources of

power entering the cubicles, such as 125/250 Vdc and/or 120/240 Vac

used to feed certain devices. A good rule to follow is to assume that all

connections are live and dangerous until proven otherwise and to avoid

all body contact with any of these voltages.

MOUNTING

The EDM-200 should be mounted in a position that enables easy viewing of

the bar graph display. Figure 4 illustrates the overall dimensions and mounting

hole locations of the EDM-200.

CONNECTIONS

Depending upon the application, the EDM-200 should be connected according

to the connection drawing shown in Figure 5 or Figure 6. All EDM-200

connections are terminated with #6 screws which have a maximum torque

rating of 9 inch-pounds (1 N•m).

AVR Ripple Amplifier

Since the AVR output consists of pulses, a strong ripple component

consisting of these pulses is present in the field current and makes the

detection of an open diode difficult. To eliminate the AVR ripple, the

AVR voltage at terminal F+ is passed through a filter, a null adjustment,

and the AVR ripple amplifier. The amplifier output is then used by the

input amplifier to cancel out the AVR ripple component in the field current.

DXCB-2 Models

Three versions of the DXCB-2 module are available. Part number

9500900100 is rated for up to 600 Vdc nominal field voltage and

can conduct up to 2.000 Adc for one second.

Part number 9500900101 is rated for up to 1.000 Vdc nominal field

voltage and can conduct up to 5.000 Adc for one second.

Part number 9500900102 has identical ratings to part number

9500900101 but has a higher range of jumper-selectable trip voltage

values.

Reference Table 3 for jumper-selectable trip voltages for each model.

INSTALLATION

48.6 lb (22.1 kg)

16.25 x 11.22 x 10.52 inches

(412.6 x 285.0 x 267.2 millimeters)

The DXCB-2 is typically preinstalled in the excitation control system. If

replacement is necessary, carefully label and document each of the

connections to the DXCB-2 in order to properly reconnect the new module.

The DXCB 2 must be monitored and adjusted to fit the specific application

at initial startup, whether it is a new unit or a replacement.

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.

Relay Driver

The relay driver consists of a transistor that controls the relay (K1) coil

voltage.

Bar Graph Display

This ten-segment indicator graphically displays the level of ripple and is

used during EDM-200 calibration and for monitoring EDM-200 operation.

AVR Ripple Amplifier

Since the AVR output consists of pulses, a strong ripple component

consisting of these pulses is present in the field current and makes the

detection of an open diode difficult. To eliminate the AVR ripple, the

AVR voltage at terminal F+ is passed through a filter, a null adjustment,

and the AVR ripple amplifier. The amplifier output is then used by the

input amplifier to cancel out the AVR ripple component in the field current.

Power Supply

EDM-200 circuitry operates from a regulated +14 Vdc source that is provided

by the transformer-rectifier type power supply. The relay output will be

inhibited and the bar graph display may indicate incorrect information until

the input voltage is at least 50% of nominal.

Variable Bandpass Ripple Amplifier

When all of the rotating diodes are operating normally, the field current

ripple is of small amplitude and high frequency. When a diode is faulty,

the ripple is of large amplitude and low frequency (one-third or one-sixth

of normal). Thus, the ripple amplifier has a high gain at low frequencies

and a low gain at high frequencies.

The amplifier provides adjustment of the high frequency gain to provide

compatibility with a wide variety of brushless generators.

Precision Rectifier

This rectifier converts the ac output of the ripple amplifier to a dc signal.

Inverse Timer

The dc output of the precision rectifier passes through an inverse timing

network to provide prompt tripping for a shorted diode but allow longer

delays for an open diode.

INTRODUCTION

The EDM-200 Exciter Diode Monitor connects to the exciter field circuit

and monitors the output of the brushless exciter power semiconductors.

The EDM-200 can detect the failure of a power rectifier in the brushless

exciter which fails in either the open or shorted mode.

A set of Form C contacts provides alarm annunciation. A bar graph display

enables easy onsite calibration and monitoring of EDM-200 operation.

FUNCTIONAL DESCRIPTION

EDM-200 functional description is illustrated in Figure 3 and described

in the following paragraphs.

Input Amplifier

Resistor R is connected in series with the negative lead to the exciter

field. The small voltage drop developed across R is amplified by the

input amplifier to approximately 1 volt when the generator is unloaded.

During various load conditions, the amplifier output will increase from 1

volt to about 4 volts.

APPLICATION:

The Electronic Manual Voltage Control MVC-300 allows a generator’s output

voltage to be controlled manually by a potentiometer or automatically by a

voltage regulator. It is used as a back-up system for the automatic voltage

regulator. The unit can be mounted on a control panel in ground vehicles,

stationary equipment or shipboard locations.

FEATURES:

• Designed to operate with all Basler voltage regulators rated

at 7 amperes continuous and below

• Completely solid state

• 120-240 Vac operation

• Multiple field output ratings

• Automatic voltage build-up circuit

• Small and light for easy panel or door mounting

• CSA approved/UL recognized

• Available from stock

The Electronic Manual Voltage Control MVC-300 is a solid-state device en

closed by a wrap-around metal chassis. The MVC-300 is for mounting through

a panel with controls accessible from the front of the panel or can be mounted

behind the panel. A terminal strip located on the rear of the device facilitates

installation. A manual voltage adjust potentiometer and a manual-off-auto

switch are provided on the front face of the unit. For use of a user-supplied

external manual adjust potentiometer or for adjust by a motor operated control

(MOC), order MVC-301. The MVC-300 and MVC-301 are designed to operate

with Basler voltage regulators powered from 120 or 240 volt AC sources up to

320 Hz. The adjustable output of the MVC-300 supplies power to 32. 63 or 125

volt fields at 7 amps.