Product Description:

The PSI63C0.766-L2 is a medium-frequency inverter produced by Bosch Rexroth Indramat in the PSI Frequency Inverters series. In resistance-welding cells, it converts three-phase high-voltage mains power into regulated medium-frequency current so the welding transformer delivers stable heat to the workpiece. By controlling energy in millisecond ranges, the unit supports consistent nugget formation and limits spatter in automated body-in-white lines. Its compact footprint also suits robot-mounted cabinets where space and weight are restricted, and the regulated output helps keep weld heat stable from cycle to cycle.

Incoming utility power can vary between 480 – 690 VAC, and the inverter draws a nominal 110 A from that supply bus. A TriCore processor coordinates weld timing through an EtherNet timer and enforces a minimum pre-weld or squeeze phase of 16 ms. Complete energy profiles can be repeated at 1000 Hz, with real-time commands exchanged on the built-in Ethernet/IP network. Up to 32 electrodes can be addressed from one controller, which helps keep multi-gun stations synchronized during repeated weld sequences. An air-cooled path removes cabinet base losses of 100 W and permits a maximum cooling loss of 420 W, so the housing requires 100 mm of clearance on every ventilated side to maintain airflow and temperature limits.

During each weld pulse, the power stage can supply a primary current of 800 A, which the downstream transformer converts to as much as 36 kA on the secondary side. Line conductors must be at least 35 mm² to limit voltage drop at these currents, and the spring terminals accept lugs up to 50 mm². The enclosure measures 463 × 239 × 146.5 mm, which matches standardized 19-inch frame depths and helps simplify cabinet layout. This size also allows the inverter to fit into compact electrical enclosures placed close to the welding transformer and related control hardware.