500 hp inverters: Lotta ponies!
Hitachi America Industrial Systems Division introduced a high-capacity SJ700 Series of inverters. The series extends the company’s model range up to 500 hp, and significantly expands performance, capabilities and functions. Three models, 250 hp, 400 hp and 500 hp are being released at this time. The SJ300 remains to cover the range from 200 hp and below.
The company says that, with this new series, it reasserts its technological leadership, providing an improved sensorless vector (SLV) control algorithm enabling the inverter to develop more than 150% starting torque at 0.3 Hz. Using Hitachi’s unique “0 Hz Domain” open-loop control mode, the SJ700 can develop 130% torque at 0 Hz, making it ideal for vertical lift applications. At the same time, the company has greatly simplified autotuning.
The company claims its Easy Sequence ( EzSQ) built-in programming function is like having an Industrial control system built into the inverter. In many cases, the need for a separate PLC can be eliminated. Control programs can be developed on a PC, then downloaded to the inverter.
The SJ700 also has built-in RS485 Modbus/RTU communication, and options for other communications networks, such as Ethernet Modbus/TCP, DeviceNet, Profibus, and LonWorks. The SJ700 can be configured via the front-mounted keypad or using Hitachi’s ProDrive PC-based software. The SJ700 carries CE, UL and c-Tick marks, and is RoHS compliant.
— Edited by C.G. Masi , senior editor
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