Product Description:

The PST6100.323-L is a thyristor power unit produced by Bosch Rexroth Indramat within the PST Thyristor Power Units series. The unit synchronizes current flow to welding transformers and other connected loads, allowing programmable energy delivery in robotic and fixture-mounted welding cells across industrial automation environments. It integrates cabinet control functions, memory, and fieldbus links so a PLC can select welding schedules without discrete relays. The compact design fits standard control panels and helps conserve cabinet space where multiple control components must be installed side by side.

Basic cabinet heat loss is 70 W, so the enclosure must dissipate that amount of heat during operation. Cooling is handled by air cooling, which eliminates the need for water circuits and simplifies panel layout. Control electronics are supplied by an isolated 24 V DC logic source that remains separated from the power thyristors. The housing has an IP20 degree of protection, so the unit is intended for installation inside a protected panel. Power terminals accept conductors up to 50 mm², matching the nominal output current of 130 A. MOV overvoltage protection helps limit surge stress on the semiconductor stack, and operation must remain within the stated duty cycle to avoid excess heat buildup.

The unit supports transformers up to 76 kVA. It is approved for operation at elevations up to 2000 m above sea level and at ambient temperatures up to 55 °C. A lithium AA 3.6 V backup battery preserves the 256-step program memory during control power loss. Sequence control uses an INTERBUS timer, while data and diagnostics are transmitted over the INTERBUS-S fieldbus to the PLC. Fifteen firing electrodes provide separate channels for welding guns, and the control logic limits channel runtime to protect the power section. The assembly weighs 12.5 kg, which helps keep cabinet mounting loads moderate.