3.3 Remote control capability
Some MVC models support remote control functionality, allowing operators to perform control operations from a safe location outside the generator room. This feature is useful for:
Power plants located in remote areas
Power generation sites with harsh environmental conditions
In situations where there are special requirements for the safety of operators
It is of great significance.

4. Typical applications and connection methods
4.1 Typical System Connections
The typical connection method of MVC in the excitation system is shown in Figure 1. In the standard configuration, MVC and AVR are connected in parallel to the excitation circuit, and the excitation is controlled by which device through mode switching.
Connection points:
The input power of MVC is taken from the same power source as AVR (usually the generator output or PMG)
The output of MVC is connected to the excitation control circuit of AVR
When the mode switch is in the "OFF" position, MVC is completely isolated; When in the "MANUAL" position, MVC takes over excitation control
4.2 Matching with Basler Voltage Regulator
The MVC series is specifically designed for Basler voltage regulators and has good compatibility with Basler AVC series, BE series, and DECS series excitation products. This supporting advantage is reflected in:
Interface matching (no additional conversion or adaptation required)
Coordination of control characteristics (smooth connection between manual control range and AVR automatic adjustment range)
Easy installation (standardized design from the same supplier)
Recommended supporting products (from product information):
AVC63-12, AVC63-4/4D, AVC63-4A, AVC63-7/7F voltage regulators
BE350 Voltage Regulator
DECS-150, DECS-250, DECS-250N digital excitation control system
4.3 Emergency operation process
When AVR malfunctions, the operator should follow the following typical process:
Confirm AVR malfunction (abnormal output voltage, alarm indicator light on, etc.)
Switch MVC from "OFF" to "MANUAL" mode
Observe the output voltage of the generator
Slowly adjust the MVC control knob to restore the voltage to near the rated value
Continuously monitor voltage in manual mode and make minor adjustments based on load changes
After AVR maintenance or replacement is completed, switch control back to automatic mode
5. Selection Guide
5.1 Selection Decision Factors
When choosing an MVC model, the following factors should be considered:
1. Power level of supporting AVR
Small AVR (such as AVC63-4 series) → MVC-104
Medium sized AVR (such as AVC63-12 series) → MVC-108
Large AVR (such as DECS series high-power applications) → MVC-232
2. System voltage level
120 Vac system → MVC-104 or MVC-108
240 Vac system → MVC-232
3. Is remote control capability required
Select the model with remote control function according to the operator's location requirements
5.2 Installation precautions
Ensure that the input voltage of MVC matches the system voltage
Connect the wires correctly according to the connection diagram, paying attention to polarity and phase
MVC should be installed in a location that is easily accessible to the operator
Clearly label the operation instructions and status indicators of MVC on the control panel
6. Maintenance and troubleshooting
6.1 Preventive Maintenance
The MVC series adopts a robust industrial grade construction with extremely low maintenance requirements. Suggested maintenance measures include:
Regularly check if the wiring is secure
Keep the equipment clean to prevent dust accumulation
Regular functional testing (switching modes and verifying functionality without interrupting generator operation)
6.2 Functional testing
Under the condition of not interrupting the normal operation of the generator, the following functional verifications can be performed:
Confirm that MVC is in the "OFF" position and AVR is working properly
Switch briefly to the 'MANUAL' position
Verify that MVC can control excitation current (observe small changes in output voltage)
Immediately switch back to the "OFF" position and confirm AVR recovery control
If the switching process is smooth and there are no abnormal voltage fluctuations, then the MVC function is normal
6.3 Common Problems
Possible causes and solutions for the problem
After switching to manual mode, if the voltage loses control and there is an internal fault in the MVC, immediately switch back to OFF mode and replace the MVC
Insufficient manual control range. MVC model does not match the system. Check the selection and consider upgrading to a larger capacity model
During switching, if there is excessive voltage fluctuation and the control characteristics do not match, check the wiring to ensure that the control range of AVR and MVC is coordinated
7. Engineering recommendations for system integration
7.1 The Value of Redundant Design
In critical power generation applications, it is recommended to include MVC as a standard configuration in the excitation system design. Although the reliability of AVR is already high, the emergency manual control capability provided by MV C has irreplaceable value in the following situations: