Product Description:

Bosch Rexroth Indramat manufactured the PSI64C0.735-W1, a member of the PSI Frequency Inverters series. Classified as a medium-frequency inverter, it converts factory mains energy into regulated high-current pulses for resistance welding stations and automated joining cells. By tailoring the waveform applied to welding transformers, the unit controls heat input and weld duration, making it an integral power component in robotic lines that demand repeatable seam quality and rapid cycle times. It mounts inside machine cabinets where water cooling is already present.

Designed for 400–480 VAC three-phase supplies, the inverter draws a mains nominal current of 220 A. Its power stage is water cooled; with a coolant flow of 4 l/min, the pressure drop across the heat exchanger is 0.6 bar, keeping semiconductor temperatures within limits. The enclosure carries a protection rating of IP20 and weighs 40 kg, so it must be installed inside a ventilated cabinet. Cabinet base loss is 69 W, rising to 210 W at maximum output, while the surrounding cabinet must also dissipate converter heat. The connectors require conductors with a 95 mm² cross-section. An EtherNet timer is used to schedule weld pulses, and the electronics are prepared for a fieldbus module to integrate with cell or line controllers.

During production peaks, the device can deliver a primary current of 1600 A, and the cooling circuit is rated to absorb up to 700 W generated by switching losses. Full performance is available at installation heights up to 2000 m, which fits typical plant elevations. Memory resources store 256 welding programs, and hardware outputs address 32 electrodes, enabling quick changeovers between product variants and simultaneous multi-gun operation. The inverter also tracks 256 welding points for process traceability, and the cooling loss must be considered when sizing cabinet heat exchangers.