Product Description:

The KDA 2.1-150-3-LQD-U1 is a spindle drive produced by Bosch Rexroth Indramat for the KDA Spindle Drives series. This unit converts fixed-voltage DC power into precisely regulated three-phase output for high-speed motor windings, allowing a machine-tool control system to adjust spindle torque and speed in real time during cutting operations. When installed in a CNC cabinet, it forms the electrical link between the motion controller and the spindle motor, supporting drilling, milling, and grinding cycles that require steady acceleration, controlled deceleration, and reliable holding behavior under continuous industrial use.

Electrical conversion relies on a DC bus of 300 VDC, which provides the energy reservoir for the pulse-width-modulated inverter stage. The power section is rated for a continuous output of 150 A, allowing the drive to supply large spindle motors during demanding material removal without current foldback. Thermal energy is removed by a mounted heat sink blower, and the unit uses forced cooling to push air across the fin stack and keep internal temperatures under control. The blower operates from an auxiliary supply of 115 V at 50/60 Hz, which keeps ventilation separate from the main DC link.

Command signals enter the drive through the SERCOS interface, a fiber-optic network that carries speed references and diagnostic data between the controller and the spindle drive. A separate channel handles the digital position command value, which supports accurate spindle orientation during tool changes and other indexed motion tasks. The control electronics are intended to operate within 5 to 45 degrees Celsius, so cabinet air conditions must keep the internal environment within that range. Installation is permitted up to 1000 m above sea level; above that height, lower air density can reduce cooling performance and may require derating.