Hitachi Inverter Suited to Vertical Lift Applications
Hitachi America Ltd., Industrial Components & Equipment Division, Tarrytown, N.Y., has unveiled its SJ700-2200HFU2 model inverter, with a 440 A output current capability, ideal for vertical lift applications. This new model fills in the gap at 300-350 hp in the SJ700 series, which now completely covers the range from 0.5 to 600 hp.
The SJ700 significantly expands on the performance, capabilities and functions of its predecessor, the SJ300. Hitachi highlighted an improved vector control algorithm and auto-tuning function that enables the open-loop SJ700 (SLV) to develop more than 200 percent starting torque at 0.3 Hz. Using Hitachi’s unique "0 Hz Domain" open-loop control mode, the SJ700 can develop 150 percent torque near 0 Hz, suited to vertical lift applications.
In closed-loop mode with encoder feedback, the SJ700 performance is unmatched, delivering in excess of 100 percent torque at 0 Hz. Another major new element in the SJ700 is Hitachi’s EzSQ (easy sequence) built-in programming function. 'It is like having a PLC inside the inverter', Hitachi said. 'In many cases, the need for a separate PLC can be eliminated.'
The user develops EzSQ programs on a PC, and then downloads them to the inverter via the simple-to-use configuration/programming software provided at no charge. The SJ700 can deliver true servo-like position control when mated with a general-purpose induction motor and encoder, offering a low-cost motion control alternative. The SJ700, given a position command, speed command, and acceleration/deceleration times, can move the motor shaft from position A to position B following the defined profile and then maintain the shaft in "servo lock" status.
Hitachi has added other new features to the SJ700, such as patented micro-surge voltage suppression (to protect the motor winding insulation), advance trip avoidance functions, configurable sink/source logic on I/O, built-in dynamic braking circuit in models up to 30 hp (22 kW), built-in EMC filter up to 75 hp (55 kW).
The SJ700 also includes built-in RS485 Modbus/RTU communication, and options for other communications networks, such as Ethernet Modbus/TCP, DeviceNet, Profibus and LonWorks. Others, such as Ethernet/IP are in the works. The SJ700 can be configured via the front-mounted keypad or using Hitachi’s ProDrive PC-based software.
Designed to be a product for the global market, the SJ700 carries CE, UL, cUL and c-Tick marks, and is RoHS-compliant.