The Basler MVC‑300 is a manual voltage control unit designed for local operation of generator voltage regulators and breaker controls. Identified by part number 9121000106, this unit provides manual raise/lower control of generator voltage, as well as open/close control for the main circuit breaker. It is an essential interface for operators during commissioning, testing, and manual override situations.
The MVC‑300 features dedicated raise and lower pushbuttons for voltage adjustment, along with open and close controls for the breaker. It includes status indication LEDs for power, voltage regulation, and breaker position. The unit is designed with fail‑safe logic and anti‑pump protection. It is housed in a compact, rugged enclosure suitable for panel mounting.
Control voltage: 120 VAC or 24 VDC depending on configuration. Outputs: relay contacts for voltage raise/lower and breaker trip/close. Operating temperature: -10°C to +60°C. The unit includes surge suppression and transient protection for reliable operation. Connections are via screw terminals for secure wiring.
The MVC‑300 interfaces with the generator's AVR and breaker control circuits. When the raise or lower button is pressed, the unit generates a pulsed or maintained signal to the AVR, adjusting the voltage setpoint. The open/close buttons directly control the breaker trip and close coils through interlocked logic. Status LEDs provide visual feedback of the current state.
This control unit is used in generator control panels, power plants, and industrial facilities. It is ideal for applications requiring local manual control of generator voltage and breaker operation, providing a simple and reliable operator interface.
Mount the MVC‑300 on a panel using the provided hardware. Connect the control power, AVR interface signals, and breaker control wiring. No extensive configuration is required; the unit operates according to the connected system. A functional test after installation is recommended.
Routine maintenance includes visual inspection of connections and pushbuttons. The unit is built with high‑quality components for long service life. Periodic functional testing ensures continued reliability.
The Basler MVC‑300 manual voltage control unit provides a simple and reliable interface for local generator control, ensuring operational flexibility and ease of use.



