Product Description:

The PST6100.210-L is a power control stage manufactured by Bosch Rexroth Indramat within the PST Thyristor Power Units series. Designed for resistance welding and related thermal processes, the unit modulates primary transformer current with phase-fired thyristors so that downstream automation can regulate heat output precisely. By fitting into recessed switchgear bays, it provides a compact, panel-integrated source of controlled high current for machines or cells that are coordinated over fieldbus networks.

Its electrical handling capability centers on a nominal system current of 130 A, allowing the device to switch large secondary currents without saturating the silicon devices. A logic input requirement of 24 V DC powers the gating circuits and diagnostic LEDs, isolating low-level controls from the main line. The power unit supports a maximum duty cycle of 50%, so conduction time must remain within the allowed thermal window. Internal dissipation reaches 70 W under continuous operation, so enclosure ventilation must be maintained. When paired with a welding transformer, the module can command up to 76 kVA of apparent power, making it suitable for medium-capacity spot or projection weld stations. Overvoltage events are suppressed by an MOV, and timing commands are exchanged through the PROFIBUS timer interface.

The assembly carries a protection rating of IP20, so it must be mounted inside a cabinet and kept free of conductive dust. Heat is removed by an air-cooled forced-flow design; incoming cooling air should not exceed 45 °C, and the surrounding workspace may reach 55 °C without derating. The device can be installed at elevations up to 2000 m and still satisfy dielectric spacing rules. Power terminations accept copper conductors up to 50 mm², and the recessed mounting style leaves the heat sink flush with the panel surface. Integrated temperature monitoring feeds alarms to the controller before safe limits are exceeded.