Product Description:

The S7720C-NAF2-PM is a servo drive built by Kollmorgen and belongs to the S700 Servo Drives series. As a power stage and control interface, it converts three-phase line voltage into regulated motor currents so that synchronous or induction servomotors follow precise velocity and position commands in automated machinery, robotics, and conveyor systems. It integrates safety, thermal management, and braking interfaces into a single module to streamline panel layout in factory environments.

The drive accepts mains in the range of 208 to 480 V and delivers a continuous phase current of 72 Arms, enabling it to operate medium-to-large axes without external boosters. Apparent input demand reaches 50 kVA, which affects upstream supply sizing and cable selection. Internal IGBTs pulse at 8 kHz, providing fine torque resolution while keeping switching losses manageable. Safety is handled through a dual-channel STO circuit that meets torque-off performance requirements. With an output current form factor of 1.01, the inverter maintains near-sinusoidal motor currents, and the residual voltage drop of 6 V reduces DC-link losses. A cold-plate option exports heat to an external cooler, and the fan-controller expansion card modulates airflow to match operating demand. Peak current is permitted for 5 seconds, and mechanical relays limit commanded start cycles to 30 per hour.

Dynamic braking is handled by an external chopper network that can absorb 8 kW continuously and up to 50 kW during short deceleration events at 400 V. A 10 ohms resistor keeps the brake transistor within its thermal envelope. Under rated load, the power stage releases 1005 W of heat, whereas standby operation produces only 24 W. These values are used when selecting liquid or forced-air cooling capacity. Thermal losses remain controlled within the power stage, while excess energy is routed to the brake resistor during rapid speed changes.