Sprint Electric presents its extended range of digital DC drives up to 2,250 amps. The drives of the PLX range are ideal for controlling DC motors used in heavy industry applications such as metalworking, steel mills, mining or the cement, rubber and plastics industries. PLX drives are able to regenerate energy back to the mains supply under braking without the need for expensive, complex intermediate storage, resistive dumping or additional power bridges. Available in current ratings up to 2,250 amps at supply voltages up to 690 VAC, the motor controllers are compact, powerful, flexible and easy to program thanks to the drive.web control technology.

DC drives of the PLX range are available as two quadrant or regenerative four quadrant types. The four quadrant model uses two thyristor bridges to enable it to motor and brake in both directions of rotation. This allows it to reverse the torque to slow the load very gently or almost instantaneously, regenerating energy at the same time. Unlike an AC drive, it is able to generate full torque at zero speed, enabling the load to be held stationary in complete safety without the need for mechanical brakes, an especially useful feature for winders and hoists. This ability means DC is also ideal for applications such as mixers, extruders and rollers that require high starting torques and accurate control at low or zero speed, as well as for paper machines, wire drawing and machining.

All models ranging from 650 to 2,250 amps (980 kW/1,320 hp) are offered with two AC busbar position options, either top entry or bottom entry. The two options make it easier to use the existing cabling in retrofit installations, or gives the choice of wiring options for new design. The PLX range is available as high voltage (690 V AC) or standard voltage (480 V AC) models. A 690 V AC supply allows the use of 750 V DC armature motors. Compared to the standard voltage this provides an increase in shaft power, up to 1,500 kW/2,000 hp for the 2250A model., that is 50 percent more power delivered without an increased cable size.

Thanks to the control technology drive.web, the drives can be controlled over the Ethernet without the need for a PLC or supervisory computer. The control system includes graphical configuration tools that provide diagnostics and configurability of all drives on the network, either locally or remotely via the Internet. The graphical tools allow the full configuration of the drives, provide service diagnostics, full documentation and an operator interface for local control. Software functions and fieldbus communications options include Profibus, DeviceNet, CC-Link, EtherNet/IP, Modbus and CANopen.