Product Description:

The VM 50/B-TC is a modular amplifier drive manufactured by Bosch Rexroth Indramat as part of the VM Amplifier Drives series. Designed for cabinet installation, it converts line power into a stabilized DC link that feeds multiple servo and spindle axes in automated machinery. By supplying energy and monitoring protection functions, the module forms the electrical backbone of coordinated motion controllers that rely on rapid regenerative power exchange, and it integrates directly with Indramat inverter cards through an internal bus while providing relay feedback to the supervisory PLC. This arrangement supports shared bus operation across several connected axes without requiring a separate supply unit for each motor channel.

The power section is dimensioned for a continuous output of 50 A, allowing it to source or absorb the armature currents demanded by medium-frame servo axes during acceleration and braking cycles. It accepts a mains input of 380 V AC at 50 Hz through a 3/PE AC connection, so phase-balanced supplies with protective earth can be wired directly to the X31 line terminal. Auxiliary electronics, gate drivers, and relay logic are energized from a separate 24 V control supply, which keeps the monitoring circuitry active even when the main contactor is open. These values must be observed when the module is installed in a multi-axis drive cabinet.

The internal capacitor bank charges the DC bus to a nominal 520 VDC, providing headroom for energy recirculation without saturating connected inverters. If the bus falls below 400 V, an undervoltage trip disconnects the load to help prevent uncontrolled motor behavior, and overtemperature protection opens the heat-sink relay if the baseplate rises above 100 °C. During a bridge-to-bridge fault, the BTB status contact opens to signal downstream units and the host controller.