Product Description:

The PST6100.320-L is a thyristor power unit manufactured by Bosch Rexroth Indramat and belongs to the PST Thyristor Power Units series. In automation line heaters, infrared ovens, or transformer-based weld controls, this device modulates mains voltage through phase-angle firing so resistive or inductive loads receive the precise thermal or magnetic power requested by a supervisory PLC. Its control method allows the commanded output to track changing process demand during regulated heating and transformer-fed power applications.

This power unit’s logic electronics are energized from a 24 V DC control supply, while the load circuit can deliver up to 130 A of nominal system current to the connected transformer or heating element. Cooling is handled by an internal fan, so the unit is air cooled. The assembly is rated at IP20, so it must be mounted inside a cabinet. Safe continuous operation is permitted up to an ambient temperature of 55 °C, and the inlet air for the fan may not exceed 45 °C. An MOV network provides overvoltage protection across the thyristors, and an INTERBUS timer card allows synchronized firing commands from the fieldbus. The unit accepts supply transformers as large as 76 kVA, and if cabinet altitude stays below 2000 m, no derating is required. Control wiring can be landed on terminals up to 50 mm², matching typical feeder sizes used in medium-power heater banks.

Total cabinet loss is limited to 70 W, so forced airflow inside the enclosure is usually sufficient to remove the heat. A maximum duty cycle of 50% protects the semiconductor junctions during repetitive high-current bursts. Physical dimensions of 239 mm front width and 463 mm overall height permit side-by-side mounting as long as a 100 mm clearance is reserved above and below for ventilation. The assembly weighs 12.5 kg, which is useful when planning panel support and handling.