Bonitron M3575T-L125 Dynamic Braking Transistor

Bonitron M3575T-L125 Dynamic Braking Transistor is a standard‑duty braking module designed to install on the DC bus of an AC drive, where it dissipates regenerated energy through a braking resistor to enable controlled, rapid deceleration and prevent overvoltage faults. It is intended for drives with DC bus field terminals and continuously monitors the DC bus voltage; when a preset threshold is exceeded, its internal control electronics turn on an IGBT that connects a resistive load across the bus, with a 375 VDC turn‑on point for 230–240 VAC systems. Key electrical ratings for the M3575T-L125 include a 125 A peak current, 32 A continuous current, and a minimum braking resistance of 3 Ω, with a compact enclosure measuring 17.75 inches high, 6.50 inches wide, and 8.00 inches deep. This model is part of Bonitron’s braking transistor family, available for 230–240 VAC, 380–415 VAC, and 460–480 VAC services; standard modules in the family are capable of up to 600 A DC and braking duty cycles up to 20%, and the device carries UL listing and CE marking.