Product Description:

The SPM 75-TD inverter module is manufactured by Bosch Rexroth Indramat for the SPM Inverter Modules series. It installs between the common DC bus and a high-speed spindle motor, delivering gate signals, condition monitoring, and protective shutdown paths so a CNC controller can drive the spindle accurately during machining and forming operations. A compact footprint, matched connectors, and fixed screw torques support installation in existing machine layouts without frame modifications.

The control electronics operate from a stabilized supply of 24 VDC, which powers logic, relay coils, and sensor reference lines independent of the high-energy DC link. Cooling airflow for the internal heat sink is supplied by a fan that plugs into the dedicated X110 socket, which helps keep fan wiring consistent. Three diagnostic channels are available, and the drive presents 3 fault code outputs that report over-temperature, over-current, or communication loss to the supervisory PLC. Feedback from the motor’s position transducer reaches the module through the X5 motor encoder connector, ensuring synchronous commutation at every speed. Mechanical safety ground is secured by a PE clamp that must be tightened to 4.5 Nm so the fault current path remains reliable. A separate test node marked as 7.8 V × SWmax is available for signal checks with an oscilloscope.

Additional field wiring leaves the module on clearly labeled ports. Alarm contacts are routed through the grouped pins X35.4/X35.5/X35.6, allowing discrete status indicators to mirror the internal diagnostics. When several inverters share a single power stack, the high-speed backplane link is completed by the X8 module link connector to synchronize firing sequences. Spindle position data from an external encoder is accepted on X55, separating high-resolution spindle feedback from the primary motor channel. Final panel mounting uses an M5 screw at the X6 support point, and the fastener must be tightened to 3.7 Nm to keep vibration within design limits.