Product Description:

The PST6100.321-L thyristor power unit is manufactured by Bosch Rexroth Indramat as part of the PST Thyristor Power Units series. It is installed between the line supply and an industrial load to modulate current flow through silicon-controlled rectifiers, giving production lines a compact alternative to magnetic contactors. The device participates in closed-loop automation by receiving firing commands from a higher-level controller and delivering proportional power to resistive or inductive elements, so temperature, speed, or process variables can be kept within narrow tolerances.

Its internal semiconductors dissipate 70 W as heat under nominal load, so cabinet ventilation must accommodate this loss. Logic and sensor circuits draw power from a separate 24 V DC control supply, isolating trigger electronics from the line supply. The unit can conduct up to 130 A of system current, enabling large single-phase or three-phase heaters to be driven without external relays. The enclosure exterior has a sealing level of IP54, which protects against dust deposits and splashed water, while live parts behind the front panel have IP20 protection against accidental contact. A 50% duty-cycle rating supports cyclic heating profiles, and forced air moves through the heat sink to maintain semiconductor junction temperature.

The assembly weighs 12.5 kg, so it can be panel-mounted without additional bracing. Reliable performance is stated for ambient temperatures up to 55 °C and installation heights not exceeding 2000 m, after which derating may be required. Overall dimensions of 463 x 280 x 239 mm allow placement in medium control enclosures, provided the cooling air entering the chassis remains below 45 °C. An integrated MOV network clamps transient overvoltages, and on-board sensors forward alarms through the INTERBUS timer channel while 50 mm² terminals accept the supply conductors.