Product Description:

The PST6250.145-L belongs to the PST Thyristor Power Units series manufactured by Bosch Rexroth Indramat. As a thyristor power unit, it gates line voltage into controlled current pulses for medium-sized welding or heating transformers, allowing accurate power regulation in automated production cells. It is intended for cabinet installation and integrates into low-voltage control architectures through a 24 V timer interface. The enclosure is suited for industrial settings while still allowing the airflow needed for internal cooling.

This unit can conduct a continuous nominal current of 200 A, helping the connected transformer receive stable RMS amperage during each half cycle. It is compatible with utility grids operating at 50/60 Hz, so no line-frequency adaptation is required when the equipment is used in different regions. All internal logic and gate-drive boards draw from a dedicated 24 V DC control supply, separating low-power command circuits from the high-power load path. The trigger sequence supports a 50% duty cycle, which allows equal on and off periods within the operating cycle. A cabinet-mounted design with an IP20 protection rating helps guard energized parts from incidental contact while still permitting convection airflow through the housing.

The unit produces a 70 W cabinet heat loss that must be removed through the specified air path, and it is built as an air-cooled assembly. Continuous operation is permitted at a maximum ambient temperature of 55 °C, provided the incoming cooling air does not exceed 45 °C. Installations are approved up to a maximum altitude of 2000 m before current derating is required. A metal-oxide varistor limits overvoltage spikes on the mains terminals, and a 2.2 kΩ de-excitation resistor bleeds stored energy from the transformer. Wiring lugs also accept conductors up to 95 mm² so the rated current can be carried without excessive heating.