Product Description:

The MIV0303-1-B1 is an inverter unit produced by Okuma and supplied within the MIV Servo Drives series. It works as the power interface between a CNC controller and multiple axis motors, converting DC bus energy into controlled three-phase output for vector speed and torque regulation during machine-tool automation. By allocating two inverter sections labeled L and M, the unit can drive separate axes while maintaining compact cabinet utilization.

The L side is rated at 4 hp, equivalent to 3.0 kW, giving enough headroom for medium-inertia feed axes on machining centers. The same ratings apply to the M side, allowing symmetrical power distribution when identical mechanical loads are present. Both sides can operate either a BL motor or a PREX motor; these Okuma synchronous servomotors differ in rotor construction but share feedback and current loop characteristics, so one inverter model can service both. Parameter storage is handled by the control ROM designated Standard ROM 1, meaning the firmware includes generic position-loop and spindle functions without optional expansions. Peak current modulation and protection logic are executed by the dual gate arrays mounted on the unit’s carrier boards, keeping inverter switching synchronized with encoder feedback.

The power semiconductor drive, isolation, and diagnostic tasks are located on the ICB1 inverter control board, which plugs directly into the chassis and communicates over Okuma’s high-speed fiber link. Within the closed cabinet, the heat-sink airflow is coordinated by the host Okuma cooling fan harness. Drive configuration through the MIV Servo Drives maintenance console records unit identity as an Okuma Inverter Unit, providing system software with capacity data so that over-current thresholds and regeneration duty are scaled correctly during dynamic tapping, rapid traverse, and contouring moves.