Product Description:

The SM 25/50-TC1 is an AC inverter built by Bosch Rexroth Indramat for the SM AC Inverters series. It interfaces between the plant’s 24 V control logic and the mains-driven motor, producing an adjustable output frequency to match speed profiles. Integrated tacho feedback and diagnostic contacts enable closed-loop regulation, while an axial blower mounted on the heat sink keeps the power electronics within thermal limits. The unit is intended for cabinet installation in conveyor, winding, and positioning equipment.

During steady operation, the inverter supplies a rated motor phase current of 25 A, giving enough margin for medium-frame induction machines used in material handling. Short overload demands are absorbed by a two-second peak capability of 50 A, which covers acceleration and dynamic braking events without tripping the drive. Internal switching and conduction losses are limited to 200 W, so the single axial blower can evacuate heat without external ducting. The blower is powered from an auxiliary line of 24 V DC, drawing 100 mA, and this separate feed keeps cooling independent of the main inverter bus. Speed can be trimmed across a ratio of 1:10,000, allowing slow creeping feeds as well as full-rated motor speed.

The inverter’s open chassis rating of IP00 means it must be mounted in an enclosure, yet its design tolerates a cabinet air temperature up to +55 °C before derating is required. Control electronics and relay circuits draw only 24 W, so the auxiliary power supply can be sized modestly and noise on the control bus stays low. At elevations up to 1000 m AMSL, full electrical ratings are maintained; above that point, cooling air density corrections are necessary. Dedicated diagnostic and ready contacts, each rated for 24 V at 1 A, provide status to the PLC, while a tacho output of 2.7 V per 1000 rpm and a reset input that accepts a 24 V pulse support monitoring and remote fault recovery.