Product Description:

The PSR4/5A-112 is a regenerative power module manufactured by Kollmorgen within the PSR Servo Power Supplies series. It supplies power with regenerative capability for BDS and ACS drive systems, converting single-phase mains power into DC bus power for connected servo drives. During deceleration, the module routes excess kinetic energy to a braking resistor instead of requiring the drive transistors to dissipate all of the resulting heat. In multi-axis automation, it provides a shared DC bus for the servomotors and manages returned energy during rapid braking events.

The supply charges the bus capacitors within a maximum of 25 ms, allowing connected axes to reach the ready state shortly after mains power is applied. During continuous operation, it can supply 12 amperes per phase, making it suitable for mid-frame servo drives without requiring oversized conductors. Input power comes from a single-phase 115 VAC source, which supports installation where higher supply voltages are unavailable. Regenerative energy is initially absorbed by an onboard resistor with a resistance of 15 ohms. The internal braking network can dissipate up to 40 W continuously before an external resistor is required. This internal capacity supports short braking moves and loads with moderate inertia while limiting the thermal burden placed on other drive components.

An external braking resistor can be connected when repeated deceleration cycles exceed the capacity of the internal resistor. The external resistor must have a minimum resistance of 5.5 ohms, because a lower value could cause excessive current beyond the module’s control range. The external circuit can dissipate up to 200 W continuously when the resistor and wiring are properly selected for the load. Even with an external braking network connected, switching and magnetizing losses produce approximately 120 W of heat inside the enclosure. Cabinet airflow must remove this heat to maintain acceptable operating temperatures around the module and adjacent drive components. The internal resistor accommodates lower braking demand, while the external connection supports applications with greater inertia or more frequent deceleration cycles.