Product Description:

The PST6250.630-L is a thyristor power unit produced by Bosch Rexroth Indramat within the PST Thyristor Power Units series. As a controlled semiconductor switch, it modulates line power delivered to industrial loads and transformer-based systems, enabling precise current shaping in automation cells that rely on short, high-energy pulses. The two-phase design is intended for recessed mounting inside a control cabinet, where it integrates with DeviceNet timing hardware and onboard temperature monitoring circuits to protect both the unit and connected equipment.

The power circuit is rated for a nominal system current of 200 A, allowing the unit to energize medium-scale welding transformers without saturation. When connected to properly sized mains conductors, it can handle a transformer apparent power of 250 kVA, while its internal logic draws only 24 V DC. Operation is limited to a maximum duty cycle of 50%, a constraint that minimizes silicon stress and matches typical short-cycle production rhythms. The housing carries an IP20 degree of protection, so it must be installed in a closed electrical cabinet where the air path remains clear for the forced-air cooling system. A MOV network on the input side clamps overvoltage events, and the 95 mm² wire range accommodates heavy-gauge conductors required for low-loss current delivery.

Thermal management is also important in this unit. Cabinet loss reaches 70 W at full rated output, and the cooling air passing through the heat sinks may not exceed 45 °C. Ambient temperature around the cabinet can rise to 55 °C before derating is necessary, provided the air-cooled path remains unobstructed. Integrated sensors relay real-time device temperature to the DeviceNet timer, enabling immediate current truncation if thresholds are approached. Total installed weight is 12.5 kg, so adequate clearance should be left for airflow around the recessed frame and for routing the two-phase supply conductors alongside the MOV-protected input terminals.