Product Description:

The PSI63C0.178-L1 medium-frequency inverter is produced by Bosch Rexroth Indramat as part of the PSI Frequency Inverters series. Engineered for resistance welding cells, the device converts three-phase supply voltage into a rectangular-wave output that feeds transformer-coupled welding guns, allowing precise energy delivery and rapid cycle times in body-in-white or general metal-joining stations. It is a medium-frequency inverter with an air-cooled enclosure for cabinet mounting in standard automation panels without external liquid circuits.

During operation, the inverter has a cabinet basic loss of 69 W, which is the idle heat that must be removed. When the current regulator is driven to maximum duty, dissipation rises to 170 W, so forced airflow keeps the semiconductors within acceptable limits. The unit accepts a three-phase input of 400 – 480 VAC and draws a nominal line current of 110 A. For short welding pulses, it can supply the transformer with a peak primary current of 800 A. The E/A_DISKR2ED I/O module handles commands through 24 V logic, while supply conductors must use a minimum connection area of 35 mm² and terminate on 50 mm² clamps.

On the welding side, the control supports two electrodes and drives two guns, and each gun can be enabled within 10 seconds of power-up. Pressure relief is delayed by a 5-second overpressure wait to protect the cylinders during operation. With a suitable PSG 3100 transformer, the inverter can deliver a maximum secondary welding current of 36 kA at a sequence frequency of 1000 Hz for stable heat input. Up to 18 programs can be stored for different welding schedules, and field devices are powered from a control bus held at 24 VDC. A stop contact rated at 3 A interrupts the gate drive during an emergency stop and also reports system status to the robot controller.