Product Description:

The PST6101.321-L is a power unit manufactured by Bosch Rexroth Indramat within the PST Thyristor Power Units series. Installed in automated welding, heating, or lighting panels, it modulates line power through two controlled thyristor legs to achieve fast, repeatable energy dosing. In an automation cell it interfaces with higher-level controllers and delivers phase-angle or zero-cross switching so transformers and resistive loads receive only the energy required by the process.

This model runs on an input of 24 V DC and can supply a nominal system current of 130 A to downstream equipment. A maximum transformer power of 76 kVA is supported, allowing the unit to feed medium-sized resistance weld transformers without saturation. The internal timing circuitry synchronizes to mains at 50/60 Hz, and the drive electronics stay functional up to an ambient of 55 °C when the specified air-cooled path is maintained. Power conversion follows a 2-phase thyristor topology, and surge stress on the semiconductors is limited by an MOV network that clamps overvoltage events. Parallel and pressure feedback channels provide 100 mA and 20 mA signals, respectively, for process monitoring. Digital resources include a program capacity of 256 steps and an INTERBUS timer for sequence control. Input logic and emergency stop wiring can switch 3 A at 24 V DC without external relays, and conductors may be terminated directly on the bus bars.

Altitude clearance reaches 2000 m, so full ratings are available in most production halls. Feeder lugs accommodate copper up to 50 mm², and the KSR sensor cable may be extended to 100 m without recalibration, giving flexible cabinet layout options. The enclosure carries a protection class of IP20, so it must be installed inside a dust-free panel but needs no additional gasketing.