Product Description:

The S7720A-NAF2-PA is a rack-mount servo drive produced by Kollmorgen and placed within the S700 Servo Drives series. It interfaces with machine controllers to convert commanded motion profiles into the three-phase currents required by brushless servomotors. By closing the torque, speed, and position loops in the drive electronics, the unit streamlines wiring, simplifies setup, and supports synchronized axis behavior for packaging lines, robotics, and other automated cells that must coordinate multiple mechanical axes under varying loads.

On the analog interface, a differential input with 20 kΩ impedance accepts ±10-volt references that are digitized to 1.25 mV resolution, and the companion output channel reproduces setpoint or diagnostic signals across a span of ±10 V with 0.38 mV granularity. The power stage delivers continuous armature current of 72 Arms and can surge to 140 Arms for fast acceleration while drawing a maximum of 50 kVA from three-phase supplies rated at 208–480 V. Proper motor pairing is supported by a minimum load inductance of 0.61 mH at 480 V, an output current form factor of 1.01, and a dv/dt limit of 4.8 kV/µs that constrains voltage stress on motor insulation.

The control board receives an auxiliary 24-volt feed that can supply 2 A for logic, encoder excitation, and the optional fan controller expansion card. During braking sequences, internal circuitry diverts up to 3 A, while a residual drop of 6 V across the transistor path helps keep bus voltage within safe margins. Functional safety is provided by the dual-channel STO architecture, allowing power removal without contactors. Active operation produces losses of 1005 W at 400 V, while disabled operation drops to 24 W; coated PCBs and a cold-plate base promote conduction cooling, and acoustic output remains below 68 dB(A) at rated speed.