Industrial AC variable frequency drives
Hitachi America, Ltd., Industrial Components and Equipment Division, produces the L700 Series of Industrial AC Variable Frequency Drives. The L700 expands on the performance, capabilities and functions of its predecessor, the L300P.
Hitachi has broadened the applicability of this series by incorporating the improved sensorless vector (SLV) control algorithm that was first developed for the SJ700 series. This allows the L700 to develop 150% torque at 0.5 Hz, purportedly ideal for a wide range of applications beyond just fans and pumps. The L700 also has a number of features built in that allegedly make the commissioning process quick and trouble-free.
Another notable upgrade in the L700 is Hitachi’s EzSQ (Easy Sequence) built-in programming function, which actually provides the functionality of a PLC built into the inverter. In many cases, the need for a separate PLC can be eliminated due to this internal capability. The program is developed on a PC and then downloaded to the inverter, using the simple-to-use EzSQ software provided at no charge.
Hitachi has designed many other new and helpful features into the L700 Industrial AC Variable Frequency Drive, such as the patented micro-surge voltage suppression (to protect the motor winding insulation), advanced trip avoidance functions, configurable sink/source logic on digital inputs, built-in dynamic braking circuit in models up to 30 hp (22 kW), a built-in EMC filter in models up to 200 hp (160 kW), and much more.
The L700 also has features customers have come to expect from Hitachi Variable Frequency Drives, such as built-in RS485 Modbus/RTU communication, and options for other communications networks, such as Ethernet Modbus/TCP, DeviceNet, Profibus and LonWorks. The L700 can be configured via the front-mounted keypad or using Hitachi’s ProDrive PC-based software.
A true global product, the L700 carries CE, UL, cUL and c-Tick marks, and is RoHS compliant.
Hitachi America, Ltd.
– Edited by Gust Gianos, Plant Engineering, www.plantengineering.com