VT-NE31-15

The VT-NE31-15 is a compact bipolar power supply unit from Bosch Rexroth Indramat’s VT-NE Power Supply Units series. It converts single-phase mains power into isolated positive and negative 24-volt rails that feed control cards, sensor loops, or analog actuators in industrial automation cabinets. By packaging dual, filtered outputs in a 1.1 kg housing, the module provides a space-saving energy source that can be clipped to a DIN rail beside valve amplifiers, motion controllers, and other low-power electronics.

The unit accepts an operating range of 230 VAC ±10% or an alternative 115 VAC input; the factory primary selection is preset to 230 VAC for European panels. A line frequency of 50/60 Hz supports operation on either common supply frequency without transformer changes. Under full load, the positive rail supplies +24 VDC, and the negative rail delivers -24 VDC. Both outputs are filtered to keep residual ripple below 5%, supporting stable analog reference signals. Power enters through a terminal strip protected by a 0.8 A slow-blow fuse, while external wiring with a cross-sectional area of up to 4 mm² connects to the same terminals. Installation uses a spring foot for EN 60715 DIN-rail mounting or optional screw fasteners. Miniature fuses on each output rail provide short-circuit isolation so that adjacent loads can remain energized if one branch trips.

At no load, the supply maintains balanced outputs of +27 VDC/-27 VDC, and a maximum branch current of 0.25 A keeps power dissipation within the Series 15 operating range. Each rail can deliver up to 6 W, matching the power requirements of typical proportional valve cards. The total mass is limited to 1.1 kg, reducing stress on the DIN rail and making the unit easier to handle during installation. Front-accessible miniature output fuses provide short-circuit protection for the connected branches. The electronics tolerate storage temperatures from -20 °C to +70 °C, allowing the unit to be stored safely in unconditioned storage areas.