Product Description:

The PSI63C0.760-W2 medium-frequency inverter is produced by Bosch Rexroth Indramat within the PSI Frequency Inverters series. In automated resistance-welding stations, it supplies controlled current to the welding transformer, coordinating squeeze, weld, and hold phases so that electrode force and thermal input remain repeatable from cycle to cycle. An onboard EtherNet/IP interface exchanges setpoints and feedback with the line PLC, while five additional digital inputs and three digital outputs handle local interlocks and status signals.

This model is water-cooled, a method that removes heat directly from the power stage and keeps switching components below their thermal limits during continuous production. It operates from a three-phase supply of 480–690 VAC, matching the higher-voltage mains often found on robotic welding lines. The internal controller clocks each welding sequence at 1000 Hz, giving the drive fine time resolution for current profiling. A minimum pre-weld, or squeeze, time of 16 ms allows rapid clamping before current is delivered, which shortens overall cycle time. Conductor terminals accept mains cables up to 50 mm², allowing large cross-section wiring to limit voltage drop over long cable runs.

The stop circuit is energized by 24 VDC control power and can interrupt loads up to 3 A, providing a dedicated stop path when welding must cease immediately. A programmable start-sequence timeout of 60 s prevents indefinite energization if the transformer does not reach the expected current, and the inverter can address up to 32 electrodes through its internal timing tables. Sixteen serial input bits and sixteen serial output bits carry compact status words over the same Ethernet channel, and the timer logic is implemented in an EtherNet-based module for deterministic task execution. Transformer leads can also be wired with 50 mm² conductors so the secondary circuit benefits from the same low-impedance connection as the mains side.