Basler MVC 236 Operating and maintenance manual

ELECTRONIC MANUAL VOLTAGE CONTROL MODULE
Model: MVC 236
Part Number: 9 2043 00 100
Publication Number: 9 2043 00 990
Revision: G 7/99

WARNING
To prevent personal injury or equipment damage, only
qualified technicians/operators should install, operate,
or service this device.
CAUTION
Meggers and high potential test equipment should be
used with extreme care. Incorrect use of such
equipment could damage components contained in the
device.
CONFIDENTIAL INFORMATION
of Basler Electric Company, Highland, IL. It is loaned for
confidential use. Subject to return on request and with the
mutual understanding that it will not be used in any manner
detrimental to the interests of Basler Electric Company.
It is not the intention of this manual to cover all details and
variations in equipment, nor does it provide data for every
possible contingency regarding installation or operation.
The availability and design of all features and options are
subject to change without notice. Should further information
be required, call Basler Electric Company, Highland, IL.

Table of Contents
List of Illustrations
List of Tables
i
Paragraph Title Page
SECTION 1 GENERAL INFORMATION
1-1 Purpose.......................................................................................................1-1
1-2 General Description.....................................................................................1-1
1-3 Specifications..............................................................................................1-1
1-4 Spike Suppresson Module ..........................................................................1-2
SECTION 2 PRINCIPLES OF OPERATION
2-1 Block Diagram Theory of Operation............................................................2-1
SECTION 3 INSTALLATION INSTRUCTIONS
3-1 Mounting......................................................................................................3-1
a. Manual Voltage Control Module Mounting ...........................................3-1
b. Spike Suppression Module Mounting...................................................3-2
3-2 Interconnection............................................................................................3-3
a. General.................................................................................................3-3
b. Input Power..........................................................................................3-3
c. Output (Field) Voltage ..........................................................................3-3
d. Frequency Selection.............................................................................3-3
e. MANUAL ADJUST Control...................................................................3-3
SECTION 4 OPERATON INSTRUCTIONS
4-1 Operation.....................................................................................................4-1
4-2 Operational Test..........................................................................................4-1
SECTION 5 MAINTENANCE AND TROUBLESHOOTING
5-1 Preventive Maintenance..............................................................................5-1
5-2 Troubleshooting...........................................................................................5-1
5-3 Corrective Action.........................................................................................5-1
5-4 Warranty and Repair Service......................................................................5-1
Figure Title Page
2-1 MVC 236 Block Diagram......................................................................2-1
3-1 MVC 236 Outline Drawing....................................................................3-1
3-2 Manual Voltage Adjust Rheostat..........................................................3-2
3-3 Spike Suppression Module Outline Drawing........................................3-2
3-4 Typical MVC 236 Interconnection ........................................................3-4
3-5 MVC 236 Interconnection with Nullmeter Circuit..................................3-5
4-1 MVC 236 Operational Test...................................................................4-2
5-1 Troubleshooting....................................................................................5-2
Table Title Page
1-1 Electrical Specifications........................................................................1-1
1-2 Physical Specifications.........................................................................1-2
5-1 Recommended Spare Parts List ..........................................................5-1

1-1
The Electronic Manual Control Module (MVC 236) provides the means of allowing a generator's
output to be controlled by a potentiometer or automatically by a voltage regulator. It is normally
used as a back-up system for the automatic voltage regulator. The MVC 236 provides a regulated
dc output to the field of the generator.
The MVC 236 is a solid-state device enclosed in a metallic, dark gray chassis and is designed for
behind-the-panel mounting. Two terminals strips located on the front of the unit facilitates installa-
tion and operation. The MANUAL VOLTAGE ADJUST control (a potentiometer) is supplied for
remote mounting. A customer supplied AUTO-OFF-MANUAL switch is required for system
operation.
Refer to Table 1-1 for the electrical specifications of the MVC 236 and to Table 1-2 for the
mechanical specifications.
Table 1-1. Electrical Specifications.
Input Power (Voltage): 45 - 70 Vac (60 Vac Nominal);
90 - 153 Vac (120 Vac Nominal);
170 - 305 Vac (240 Vac Nominal).
Input Power (Frequency): 50 to 400 Hz, single-phase.
Output Power: 32 Vdc Nominal, 36 Adc; 40 Vdc (minimum) at Maximum Po-
tentiometer Setting;
63 Vdc Nominal, 36 Adc; 79 Vdc (minimum) at Maximum Po-
tentiometer Setting;
125 Vdc Nominal, 36 Adc; 156 Vdc (minimum) at Maximum
Potentiometer Setting.
Regulation Accuracy: 2% regulation for a 10% change in input power;
5% regulation for a 30% change in input power.
Field Resistance: 0.88 W at 32 Vdc Nominal Output;
1.75 W at 63 Vdc Nominal Output;
3.47 W at 125 Vdc Nominal Output.
Dissipated Power: 85 Watts.
Minimum Residual Build-
up Voltage: 10% of 60 Vac, Nominal Rated Input;
5% of 120/240 Vac, Nominal Rated Input.
Temperature Stability: ±5% for a 50°C change.
MANUAL VOLTAGE AD-
JUST Control: A 10 kW, 1 W potentiometer is supplied as a loose item for
remote mounting.
SECTION 1
GENERAL INFORMATION
1-1. PURPOSE
1-2. GENERAL DESCRIPTION
1-3. SPECIFICATIONS

1-2
Table 1-2. Physical Specifications.
Storage Temperature: -40°C (-40°F) to +85°C (+185°F).
Operating Temperature: -40°C (-40°F) to +70°C (+158°F).
Maximum Humidity: 98% relative humidity.
Shock: Withstands up to 15 G's in each of three mutually perpendicular
axes without any degradation of performance.
Vibration: Withstands up to 2.0 G's of force over a frequency spectrum of
10 to 500 Hertz.
Dimensions: Refer to Figure 3-1.
Weight: 15.0 lbs. (6.8 kg.) net;
18.0 lbs. (8.2 kg.) shipping.
Some higher impedance power sources (such as power isolation transformers and PMG's) may
have enough inductance to cause potentially damaging voltage spikes in the power output stage
of the MVC 236 Voltage Regulator. In these cases, Basler Electric recommends the use of the
Spike Suppression Module which was supplied with the Regulator to filter out these potentially
damaging voltage spikes. Refer to Section 3 for mounting and interconnection instructions.
1-4. SPIKE SUPPRESSION MODULE

2-1
a. Refer to Figure 2-1, the Electronic Manual Voltage Control Module (MVC 236) is a phase con-
trolled, silicon controlled rectifier (SCR) bridge. By adjusting the remote mounted MANUAL
VOLTAGE ADJUST control, the firing angle of the SCR changes to provide an adjustable voltage
level to the exciter field.
b. During start-up, the build-up circuit holds the SCR power bridge at maximum output. When
the voltage has built-up to approximately 30 Vac, the internal build-up circuit relinquishes control
to the remote mounted MANUAL VOLTAGE ADJUST control.
c. The remote mounted AUTO-OFF-MANUAL switch allows transfer from the automatic voltage
regulator to the MVC 236 or from the MVC 236 to the automatic voltage control. A free-wheeling
diode remains connected to the field to allow safe switching without arcing.
d. The MVC 236 is designed to operate from 60, 120, or 240 Vac nominal sources by making a
simple tap change. Taps are also provided to select 32, 63, or 125 Vdc outputs. A jumper is used
to select the proper input power frequency.
SECTION 2
PRINCIPLES OF OPERATION
2-1. BLOCK DIAGRAM THEORY OF OPERATION
Figure 2-1. MVC 236 Block Diagram.

3-1
a. Manual Voltage Control Module Mounting. The MVC 236 must be mounted vertically for
maximum cooling. The unit can be mounted anywhere that the ambient temperature does not
exceed the environmental conditions (refer to Table 1-2). Figure 3-1 provides dimensions,
mounting hole size, and terminal strip locations and Figure 3-2 provides mounting dimensions for
the manual voltage adjust rheostat.
SECTION 3
INSTALLATION INSTRUCTIONS
3-1. MOUNTING
Figure 3-1. MVC 236 Outline Drawing.

3-2
Figure 3-2. Manual Voltage Adjust Rheostat.
b. Spike Suppression Module Mounting. The Spike Suppression Module will operate when
mounted in any position. The Spike Suppression Module can be mounted in any location where
the ambient temperature does not exceed the operational limits. Due to its rugged construction,
the Spike Suppression Module can be mounted directly on the generator. Mounting hardware
should be selected based upon the vibration and shock expected to be encountered during ship-
ping/transport and normal operation. Refer to Figure 3-3 for the outline drawing of the unit which
provides overall and mounting dimensions.
Figure 3-3. Spike Suppression Module, Outline Drawing.

3-3
a. General. The MVC 236 connects with the generator system as shown in Figures 3-4 and 3-5.
Number 14 gauge wire or larger should be used for connections to the unit.
b. Input Power. Connect one input power lead to terminal 23 (fuse) and the other to terminal 24
(fuse). Connect the jumper from TB2-TAP to the proper terminal on TB2 (60, 120, or 240) to
select the input voltage level (60, 120, or 240 Vac).
c. Output (Field) Voltage. Connect one end of a jumper wire from TB1-COM (field voltage) to
the proper terminal for the desired output (field) voltage (32 V, 63 V, or 125 V).
d. Frequency Selection. Connect one end of a jumper wire from the TB1-COM (frequency Hz)
to the proper terminal for the desired input voltage frequency range to be used (50-100 Hz or 100-
200 Hz). If the frequency range is between 200-400 Hz, remove the jumper completely.
e. MANUAL ADJUST Control. Connect the MANUAL VOLTAGE ADJUST control
(potentiometer) to terminals TB1-14, TB1-15, and TB1-16 as shown by the interconnection
diagrams. If desired, a Basler Motor Operated Control with a 10 k ohm control element can be
connected to terminals TB1-14, TB1-15, and TB1-16 instead of the potentiometer.
3-2. INTERCONNECTION
CAUTION
Meggers and high potential test equipment should be used with
extreme care. Incorrect use of such equipment could damage com-
ponents contained in the device.

3-4
Figure 3-4. Typical MVC 236 Interconnection.

3-5
Figure 3-5. MVC 236 Interconnection with Nullmeter Circuit.

4-1
With the AUTO-OFF-MANUAL switch set to MANUAL, the automatic voltage regulator is
removed from the circuit and the generator output voltage is manually controlled by the MANUAL
VOLTAGE ADJUST control. When the AUTO-OFF-MANUAL switch is set to AUTO, the
generator output voltage is controlled by the automatic voltage regulator. Complete excitation
shutdown occurs when the AUTO-OFF-MANUAL switch is set to OFF. Perform the operating
procedure as follows:
a. Start the prime mover following the manufacturer's procedure and set the MANUAL
VOLTAGE ADJUST control to minimum (fully counter-clockwise).
b. Place the AUTO-OFF-MANUAL switch to MANUAL. Note that the voltage may be
unstable (hunting) if the MANUAL VOLTAGE ADJUST is set below 30 Vac.
c. Allow the generator to build-up and then slowly increase the generator output voltage with
the MANUAL VOLTAGE ADJUST control until the generator output voltage reaches the
desired level.
To verify that the MVC 236 is operating properly, use the following procedure and the connections
of Figure 4-1 for a bench test. Notice that an automatic voltage regulator is not required for this
test.
a. With all power removed from the MVC 236, connect the unit into the test circuit as shown
by Figure 4-1.
b. Connect the FIELD VOLTAGE JUMPER for 125 Vdc.
c. With the MANUAL VOLTAGE ADJUST control fully counter-clockwise (CCW), apply 120
Vac.
d. Slowly rotate the MANUAL VOLTAGE ADJUST control clockwise (CW) and observe that
the brightness of the light bulb increases proportionally until reaching full brightness.
e. Rotate the MANUAL VOLTAGE ADJUST control fully counter-clockwise (CCW) and
remove the 120 Vac input power.
SECTION 4
OPERATION INSTRUCTIONS
4-1. OPERATION
WARNING
With the AUTO-OFF-MANUAL switch set to either MANUAL or
OFF, some of the voltage regulator terminals remain connected to
the generator and present a potential shock hazard. No attempt
should be made to remove or troubleshoot the voltage regulator
while the generator is running.
4-2. OPERATIONAL TEST

4-2
f. Connect the FIELD VOLTAGE JUMPER for 63 Vdc.
g. Apply power and slowly rotate the MANUAL VOLTAGE ADJUST control clockwise (CW)
and observe that the brightness of the light bulb increases proportionally until reaching full
brightness. Observe that the bulb is only half as bright as it was before.
h. Rotate the MANUAL VOLTAGE ADJUST control fully counter-clockwise (CCW) and
remove the 120 Vac input power.
i. Connect the FIELD VOLTAGE JUMPER for 32 Vdc.
g. Apply power and slowly rotate the MANUAL VOLTAGE ADJUST control clockwise (CW)
and observe that the brightness of the light bulb increases proportionally until reaching full
brightness. Observe that the bulb is only half as bright as it was before.
Figure 4-1. MVC 236 Operational Test.

5-1
A periodic inspection of the MVC 236 should be made to ensure that it is clean and free from
accumulations of dust and moisture. Verify that all terminal connections are clean, free of
corrosion, and tight.
In the event of defective operation, Figure 5-1 provides information to determine the probable
cause of the malfunction and corrective actions. Refer to Section 4 for the bench test procedure
(operational test).
Due to a protective conformal coating, repair/replacement of individual printed circuit board
components should not be attempted. Complete replacement of the printed circuit board is
recommended. When ordering replacement parts from Basler Electric, always specify the part
number, quantity, and description of the item. Refer to Table 5-1 for recommended spare parts.
The MVC 236 is warranted against defective material and workmanship for 18 months from the
date of initial shipment. A complete service center at the Basler Electric factory in Highland,
Illinois is geared to provide prompt turn around on parts, warranty, and non-warranty repairs.
Contact the factory before returning any item to Basler Electric for warranty or non-warranty
repair.
Table 5-1. Recommended Spare Parts List.
Reference Basler Part Number Qty Description
---------- 9 1792 01 101 1Printed Circuit Board Assembly
---------- 9 2615 00 101 1 Spike Suppression Module
CR5 08608 1Diode, Type S3680
F1,F2 21627 2 Fuse, 40 A, Type JJS40
PM1, PM2 21629 2SCR Power Module, 800 V, 40 A
R27, R28 21864 2 Resistor, Wire-Wound, 15 W, 5%, 50 Watt
R32 21565 1Resistor, Variable, Wire-Wound, 10 kW, 5%, 1 Watt
T1 BE 22746-001 1 Transformer
SECTION 5
MAINTENANCE AND TROUBLESHOOTING
5-1. PREVENTIVE MAINTENANCE
5-2. TROUBLESHOOTING
5-3. CORRECTIVE MAINTENANCE
5-4. WARRANTY AND REPAIR SERVICE

5-2
Figure 5-1. Troubleshooting.