Product Description:

The PSI63C0.120-W1 is a medium-frequency inverter produced by Bosch Rexroth Indramat for the PSI Frequency Inverters series. In resistance-welding cells and other automation stations, it converts three-phase mains power into precisely timed current pulses that drive transformer primaries. By synchronizing output frequency with welding schedules, the unit maintains stable heat input and helps minimize spatter during high-throughput production.

It accepts a mains voltage from 400–480 VAC and uses a water-cooled heat exchanger to keep semiconductor temperatures within limits. The power bus bars accommodate conductors up to 50 mm², matching the inverter’s rated current. For control integration, the E/A_DISKR2ED I/O module provides 26 discrete inputs and 19 discrete outputs, allowing a PLC to manage welding sequences and monitor process flags. A contactor-supervision routine governs safe energization; the inverter verifies closure within 250 ms, and the logic uses a 24 V timer circuit that also receives the required contactor feedback. One analog pressure output can command proportional pneumatic valves, four additional inputs acquire secondary sensor data, and program-select lines present eight bit-coded job calls to the inverter.

The contactor must open again within 200 ms, and an internal watchdog removes power when no activity is detected for 60 s. To disconnect external actuators, the stop circuit can switch loads up to 24 VDC, 3 A. Welding events follow a 1000 Hz sequence standard, which allows a minimum 16 ms preweld or squeeze window and a 10 ms spot-accept delay. Electrode life is tracked for 32 spots per tip, which helps keep replacement intervals predictable. The unit also logs each cycle through discrete outputs so process status can be monitored against configured thermal limits.