Product Description:

The PSI6300.736-L2 is a medium-frequency inverter built by Bosch Rexroth Indramat for the PSI Frequency Inverters series. The unit converts three-phase supply energy into a controlled medium-frequency output. It is used to drive induction heating, forging, or hardening equipment that requires precise current modulation.

This inverter accepts a mains window of 480 – 690 VAC, allowing installation on high-voltage plant networks. Its output bridge is chopped at 1 kHz, and this switching rhythm sets the carrier frequency seen by the load. A continuous thermal current of 110 A is available on the DC bus, while the logic subsystem stays active on the isolated 24 V DC control supply so diagnostics remain available during mains dips. An enclosure rating of IP 20 protects against accidental finger contact and suits the air-cooled path. MOV arrestors clamp surges, integrated temperature monitoring feeds status to the controller, and communication is handled through parallel, serial, or fieldbus links. An Ethernet timer coordinates pulse durations with external quench circuits, and base cabinet loss is 100 W when the inverter is idle.

During operation, the ambient ceiling is 55 °C, so cabinet ventilation must remove heat effectively. At full load, the switching devices release up to 360 W of heat that must be removed by the forced-air cooling path. The power stage can deliver 800 A RMS to the output bridge, and the downstream transformer may see a peak secondary current of 36 kA for short heating shots. Terminal bars accept conductors up to 50 mm², and auxiliary wiring fits the 35 mm² range. Integrated MOVs and current sensors work with the timer logic to shut the gate drivers if trip thresholds are exceeded, preventing semiconductor failure. Because the unit is air cooled, no external water manifold is required, which simplifies retrofit into existing induction furnaces.