NV 21/1V by Bosch Rexroth Indramat

The NV 21/1V is a power interface module manufactured by Bosch Rexroth Indramat as part of the VM Amplifier Drives series. Installed ahead of the inverter stages, it conditions incoming utility power and provides coordinated switching so that multiple servo axes can be energized or disconnected through one device. In automated material handling, packaging, or metalworking systems, the module delivers stable line power to the drive stack while preserving cabinet space and simplifying maintenance.

The module is designed for an industrial AC supply of 400 VAC, which matches typical European factory distribution networks and reduces the need for step-down transformers. It accepts a three-phase AC supply so line currents remain balanced and the connected amplifiers receive symmetrical voltage waveforms. In Underwriters Laboratories configurations, the permissible input reaches 25 A (460 V), indicating the conductor size and circuit protection required when higher U.S. line voltages are present. With a continuous power handling capability of 24 kVA, the unit can feed several medium-sized servo drives without approaching thermal limits. Its switching elements are tuned to the network base frequency of 50 Hz, so in European plants the contactor timing and inrush characteristics remain within range.

Heat removal relies on natural convection; no fans are fitted, which minimizes maintenance and helps keep airborne oil mist out of the cabinet. The aluminum housing weighs 10.6 kg, which supports stable cabinet mounting. The module has an integrated power contactor, so separate wiring to an external breaker is not required. The unit is a Line Wiring Module, so its internal busbars, terminals, and protective circuitry are intended for distributing line power to the VM drive stack rather than for motor control.