Product Description:

The S7720C-PNF2-PA is a servo drive built by Kollmorgen for the S700 Servo Drives series. It regulates brushless synchronous or induction motors in industrial automation by converting three-phase mains power into controlled output current and exchanging motion commands on field networks. With speed, torque, and safety functions integrated in a 386 mm tall housing, the drive suits installations that need precise axis control, fast transient response, and certified Safe Torque Off.

The drive accepts line voltages from 208 to 480 V and is protected upstream by an 80 A AC supply fuse. Under continuous duty, the power stage delivers a rated current of 72 Arms while drawing up to 50 kVA from the mains. Short-term overloads are handled with a peak output of 140 Arms for 5 s, allowing the connected motor to overcome starting inertia. Current is chopped at a switching frequency of 8 kHz, which reduces torque ripple and improves servo stiffness. The dual Profinet interface eliminates external switches, and the analog channel offers 20 kΩ input resistance with 0.38 mV output resolution for legacy control loops. A residual DC-bus drop of 6 V supports energy return during deceleration.

During continuous operation at 400 V, the power electronics release up to 1005 W of heat, which is removed through the standard heat sink or an optional cold plate. When the enable is low, dissipation falls to 24 W, permitting cabinet temperatures to stabilize. An integrated fan controller expansion card modulates airflow so that audible output stays within 68 dB(A). The mechanical package weighs 13 kg and includes provisions for liquid cooling or air guidance. The drive maintains full performance with phase inductances down to 0.51 mH, extending its range to low-inductance servomotors used in high-dynamic applications. Safety is addressed by the dual channel STO circuit, which removes power to the output stage without opening the mains contactor and satisfies SIL requirements for torque suppression.