Product Description:

The PST6100.144-L is a thyristor power unit manufactured by Bosch Rexroth Indramat for the PST Thyristor Power Units series. Installed in resistance-heating or transformer-based processes, the module gates line voltage through two antiparallel thyristors so that downstream equipment receives phase-controlled power in keeping with programmed timing signals. Its purpose in an automated cell is to modulate current precisely, reducing electromagnetic stress on connected transformers and improving overall energy efficiency and process stability.

The power section can supply a nominal output of 130 A, a level matched to welding or heating transformers up to 76 kVA. Control electronics require a 24 V DC supply, and the trigger circuit synchronizes with a 24 V timer input to coordinate firing angles. A maximum duty cycle of 50% limits thermal loading on the silicon elements while the air-cooled heat sink evacuates junction heat into the cabinet. The unit sits behind a recessed mounting frame and carries an IP20 enclosure rating, so live parts are finger-safe yet still rely on the host panel for environmental sealing. Power is taken from a grounded TN/TT line system and distributed across a two-phase topology that shares current evenly through paired thyristors.

Total cabinet dissipation reaches 70 W, and this heat must be removed by forced airflow that does not exceed 45 °C at the heat-sink inlet. Continuous operation is allowed up to an ambient temperature of 55 °C, provided altitude remains below 2000 m; above these limits, the current setpoint must be derated. Overvoltage stress on the semiconductor stack is limited by an internal MOV network, and field wiring may be connected to lugs up to 50 mm² in cross-section. The largest permissible transformer can operate with stable conduction angles without overloading the snubber network or connected wiring.