Basler Electric AVC63-7F User Manual

9302800994

D

Instructions

03/12

2012

www.basler.com

+1 618.654.2341 (USA)

[e-mail]

Model

AVC63-7F

Voltage Regulator

INTRODUCTION

The Basler AVC 63-7F Voltage Regulator is a potted unit
contained in a plastic case. The regulator controls the dc
exciter field power of conventional, 50 or 60 Hz brushless
generators that have a 63 Vdc exciter field to regulate the
generator output voltage.

Regulation is provided by sensing the generator output
voltage, converting it to a dc signal, and comparing the
signal to a reference voltage signal. An error signal is
developed and used to control the dc field power in order to
maintain a constant generator output.

SPECIFICATIONS

DC Output Power
7 Adc at 63 Vdc maximum continuous with a 240 Vac input.

Exciter field DC Resistance

9.0 Ω minimum.

AC Power Input
170 to 305 Vac, single-phase, 50/60 Hz.
Burden: 900 VA maximum at 240 Vac power.

AC Sensing Voltage
380 to 480 Vac, single-phase, 50/60 Hz.
Burden: 5VA.

Voltage Adjust Range
340 to 528 Vac using the internal voltage adjust. The
external voltage adjust provides a ±10% adjustment of the
nominal value determined by the internal voltage adjust.

Regulation Accuracy
±0.25%

Voltage Dr ift
<±1% voltage variation for a 50°C (122°F) change.

Response Time
<16 ms

Frequency Compensation
Refer to Figure 1.

Voltage Buildup
Internal provisions for automatic buildup from generator
residual voltage as low as 6 Vac at 25 Hz.

Power Dissipation
35 W maximum.

Paralleling Provisions
CT input for customer supplied 5A nominal CT. Adjustable
droop from 0 to 6% with 5A input at 0.8 power factor. CT
input burden is 2.5 VA.

Temper ature

Operating: –40 to +60°C (–40 to +140°F)

Storage: –65 to +85°C (–85 to +185°F)

Vibration
Withstands 1.2 G at 5 to 26 Hz; 0.036” double amplitude at
27 to 53 Hz; 5 G at 53 to 1,000 Hz.

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Description

Shock
Withstands up to 15 G in each of three mutually
perpendicular axes.

Agency Recognition
Certified per CSA Standard C22.2 No. 14

Weight
482 g (17 oz) net

INSTALLATION

Mounting

The regulator may be mounted in any position. Refer to the
outline drawing (Figure 2). The regulator may be mounted
directly on the generator set using ¼” hardware. Select the
proper hardware to withstand any expected
shipping/transportation and operating conditions.

Interconnection

Refer to Figures 3, 4, and 5.

1. Connect a jumper from COM to the 50 Hz terminal for
50 Hz operation, or leave the two terminals
unconnected for 60 Hz operation.

2. If an external voltage adjust control is being used,
connect the potentiometer to terminals 6 and 7 as
shown. If not, connect a jumper between terminals 6
and 7.

3. Connect the exciter field to terminals F+ and F-. Be
sure to observe polarity.

4. Connect the input power to the generator stator to
provide power to terminals 3 and E3/4. Fuse both

leads. Install the optional shutdown switch, if desired.

5. Connect the sensing input to E1 and E3/4. Th e
sensing should be connected “line-to-line”.

Paral lel Compensation

When it is required to operate the regulator in parallel with
an isolated or utility bus, in addition to the regulator
provisions, a 2.5 VA current transformer (CT) is required
(See Figures 3 and 5). This CT is connected in a generator
line and should deliver from 3 to 5 amperes secondary
current at rated load.

The phase relationship of the CT signal to the regulator
sensing voltage must be correct or the system will not
parallel properly. The CT must be installed in the line of the
three-phase generator that does not supply sensing to the
regulator.

Figures 5 and 6 show the correct CT polarity for A-B-C
phase rotation sequence. If the phase rotation sequence is
A-C-B, the CT secondary leads must be interchanged.

Reactive Droop Compensation

For reactive droop compensation, connect the CT to its
respective regulator as shown on Figures 5 and 6.

A unit-parallel switch shorts the parallel CT secondary to
prevent any droop signal from being injected into the
regulating system during single unit operation. The switch
may not be required on parallel droop compensation
applications where a voltage drop is not objectionable.

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Copyright

9302800994

D

Instructions

03/12

2 of 4

Reactiv e Differential Compensati on

CAUTION

regulator may be damaged.

On parallel reactive differential compensation applications
a contact should be used to short out the paralleling CT
secondary when that generator is not paralleled to the bus.
If the switch is not used, a voltage droop will be introduced
into the system. This is due to the unloaded generator
parallel CT not supplying its compensating signal, but
allowing a voltage drop to occur across it. Lack of this
shorting contact will also cause the voltage of the incoming
generator to fluctuate prior to paralleling. Ideally, this
contact is an auxiliary on the circuit breaker contactor that
opens when the circuit breaker is closed.

For reactive differential compensation, connect each CT to
its respective regulator. Then connect the finish of the first
CT to the start of the second CT, the finish of the second
CT to the start of the third CT, etc. Continue until all CT’s
are connected in series. The final step will be to connect
the finish of the last CT to the start of the first CT. (See
Figure 6).

Reactive differential compensation cannot be used when
paralleled with the utility or any infinite bus. If this
compensation system is used, a switching circuit must be
used to convert the system to a reactive droop
compensation system. Contact the factory for additional
information.

OPERATION

General

The following procedures provide instructions for setting
up, starting, operating, and adjusting the AVC 63-7F
Voltage Regulator. Symptoms of problems occurring during
startup that result from incorrect regulator adjustment and
certain generator system problems that resemble faulty
regulation, are included together with possible solutions.

Prel imi nary Setu p

To prevent damage to the regulator, complete the following
steps before proceeding with system startup.

1. Verify that the voltage regulator specifications conform
to the generator system requirements.

2. Ensure that the regulator has been installed and
connected in accordance with the paragraphs on
installation.

Operation at Red uc ed Speeds

During periods of prime mover idling, use the shutdown
switch to remove power from the regulator.

System Startup

1. Perform preliminary setup as described in the above
paragraphs.

2. Start the prime mover and bring up to rated speed.

Result: Voltage should build up. If not, perform field
flashing.

3. Slowly adjust VOLT adjustment or external voltage
adjust rheostat until the generator output voltage
reaches the nominal value.

4. Apply and remove load to check stability.

5. Check the regulator under normal operating
conditions.

Result: If regulation is not within range, verify the prime
mover is at rated speed.

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6. Reduce generator frequency to approximately 5 Hz
below nominal.

Result: Generator output voltage should decrease at
desired frequency.

Adjustments

Field Flashing

When the regulator is operated with the generator for the
first time, the polarity of the residual magnetism may not be
correct or of sufficient magnitude. If the residual voltage at
terminals 3 and 4 is greater than 6 Vac, replace the
regulator. If generator residual voltage is less than 6 Vac at
terminals 3 and 4, shut down the prime mover and proceed
with the following steps.

Do not flash the field with the generator in motion. The

1. With the prime mover at rest, apply a dc source
(ungrounded), of not more than 48 Vdc, to terminals
F+ (positive) and F- (negative) in series with a limiting
resistor. Use one ohm of resistance for each volt from
the dc power source with a power rating of at least one
watt per ohm. EXAMPLE: If using a 24 Vdc source,
use a 24 ohm, 24-watt resistor.

2. Allow the field to be flashed for approximately ten
seconds before removing the dc source.

3. If voltage buildup does not occur after performing
steps 1 and 2, verify the polarity of the dc source used
in steps 1 and 2 and perform again.

Frequency Roll-Off Adjustment

The AVC 63-7F underfrequency adjust is factory preset to
cause an average 2 volt drop in the generator’s line input
voltage to the regulator when the frequency is between

54.5 and 55.5 Hz (for 60 Hz applications). For 50 Hz

applications, the frequency roll-off is factory preset to
between 44 and 46 Hz. To reset the frequency roll-off,
proceed as follows:

1. Adjust the prime mover rpm to the desired frequency
compensation (corner frequency roll-off) point.

2. Adjust the front panel FREQ control CW until the
output voltage starts to drop off.

3. Bring the prime mover up to rated speed. The output
voltage should return to normal.

Stability Adjustment

An oscilloscope or other voltage recording device should
be used if a stability setting is desired that will provide the
fastest possible voltage response with good generator
stability.

1. Rotation of the front panel STAB control in the
clockwise (CW) direction will slow response time.

2. Rotation of the front panel STAB control in the counter­clockwise (CCW) direction will speed response time. If
rotated too far CCW, the generator voltage may
oscillate (hunt).

3. Rotate the front panel STAB control CCW until the
system starts oscillating and then rotate CW just past
the point where oscillation occurred.

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