The Hitachi SJ700 variable speed drive represents a dramatic step change in the state of the art for inverter technology, it being the first off-the-shelf unit with integral easy sequence programmable functionality (EzSQ) as standard.
It also incorporates a brand new patented power switching technology to reduce dVdT, with the IGBT (insulated gate bipolar transistor) stack at the heart of the drive, which is associated to motor insulation breakdown by the increased terminal voltage of motors when used with AC Inverters.
It is without doubt the most powerful in it’s class, a real all-rounder among AC Inverters. The sensorless vector control makes optimal torque and revolution control possible – even on high loads. With the newEasy Sequence (EzSQ) programming software, precise positioning and safe stop according to EN954-1the SJ700 series of inverters handles complex applications with ease. Various field bus interfaces enable easy integration into a variety of networks.
The integrated Hitachi 32-bit SuperH RISC processor delivers the dynamic response needed for high-end applications. To compensate possible temperature fluctuations within the motor, which might adversely affect smooth control of the motor, an online/offline motor-autotuning function is included. A newly developed internal control process helps to drastically reduce any rotational fluctuation at low speed, which enhances process stability and precision.
The SJ700 is one of the most compact drives in its class, but offers an unprecidented array of features built-in, such as Advanced Sensorless Vector Control (closed/open loop), Starting Torque >200%, Full Torque at 0 Hz, High-Torque Multi-Motor Operation (with SLV), Motor-Autotuning (online/offline), integral easy sequence programmable functionality (EzSQ), safe stop according to EN954-1, Quick-Stop Function, RS485 and RS422 interfaces, PID Control, P/PI Control, Automatic Voltage Regulation, Motor Thermistor Input, User Macro Saving and Global Standards to CE, UL, c-UL, CTick, CSA.
The SJ700 is designed for any application, ideally suited to highly dynamic applications such as packaging, printing, textile, machine tool industries, lifts, cranes, centrifuges, extruders and any application which requires high starting torques or is subject to shock loads. There are seven inputs of which five are programmable, two programmable transistor outputs, one programmable relay output and a dedicated thermistor input terminal. Access to the terminal rails is by removing the lower front case. There is also the option of a variety of fieldbus communications.
Speed setting is either via the keypad, an external analogue or digital signals or fieldbus communications. A removable keypad with LED display comes as standard and is used for programming. The SJ700 has advanced protection sensing circuits and there are alarms for over current, over voltage, under voltage, over temperature, overload, ground fault and so forth. Automatic voltage regulation is included for output voltage control.
The SJ700 will cover from 0.75kW through to 400kW and is a truly global product and carries UL and CSA approvals as well as being CE certified for low voltage, EMC Directives and is RoHS Compliant.