Omron 3G3MX2-A4055-E High Function Inverter

The Omron 3G3MX2-A4055-E is a high-function general-purpose inverter (variable frequency drive) from the MX2 series. This drive is designed to control the speed of three-phase induction motors with rated power up to 5.5 kilowatts when supplied from a 400 Volt AC three-phase input. The MX2 series is recognized for its advanced sensorless vector control, which delivers high starting torque and precise speed regulation without requiring an encoder feedback device. Applications for this drive include pumps, fans, conveyors, mixers, extruders, compressors, and small machine tools. The compact design allows for side-by-side mounting, saving space in control cabinets.

Power and Input Specifications

The 3G3MX2-A4055-E requires a three-phase 380 to 480 Volt AC input at 50 or 60 Hertz. The rated input current is specified by the manufacturer, and the drive’s output can deliver up to 5.5 kilowatts continuous duty and up to 150 percent overload for 60 seconds for high starting torque applications. The drive uses IGBT technology with a high switching frequency that reduces motor audible noise while maintaining high efficiency. Built-in EMC filters are included to reduce conducted emissions, helping the drive meet European EMC directive requirements when installed with proper cabling practices. A DC bus choke is integrated to suppress harmonic distortion and improve the input power factor. The drive is equipped with a cooling fan that operates only when needed, extending fan life and reducing dust accumulation.'

Sensorless Vector Control and Performance

The MX2 drive employs advanced sensorless vector control algorithms that estimate rotor speed and position from measured motor voltages and currents. This technique allows the drive to produce 200 percent starting torque at 0.3 Hertz, enabling heavy loads to start smoothly from standstill without stalling. Speed regulation is within plus or minus 0.5 percent of synchronous speed over a 50:1 speed range, adequate for many open-loop applications. The drive also includes auto-tuning procedures that measure motor parameters, including stator resistance, leakage inductance, and magnetizing current, optimizing the control model for the connected motor. For applications requiring even tighter speed control, the MX2 supports optional encoder feedback cards to implement closed-loop vector control. The acceleration and deceleration times are adjustable from 0.01 to 3600 seconds, with four selectable S-curve patterns to smooth mechanical transitions.

Built-In Communication and I/O

Standard on the 3G3MX2-A4055-E is an RS-422/485 communication port supporting Modbus RTU protocol. This network allows a PLC or HMI to read and write inverter parameters, control start/stop and speed, and monitor output frequency, current, and fault status. Option cards are available for popular fieldbuses such as Profibus DP, DeviceNet, CANopen, and EtherCAT, enabling integration into larger automation architectures. The drive’s digital inputs, typically seven, can be configured for a variety of functions such as forward run, reverse run, multi-speed selection, fault reset, and external trip. Analog inputs include one voltage input (0-10 V) and one current input (4-20 mA), providing flexibility for speed reference from a PLC analog output or potentiometer. Two open-collector outputs and a relay output indicate drive status such as running, speed arrival, or fault.

Safety and Protection Functions

The MX2 inverter incorporates a safety stop function compliant with EN 954-1 category 3 and EN ISO 13849-1 PL d when properly wired. The Safe Torque Off (STO) inputs disconnect the drive’s gate drive signals, preventing the motor from generating torque even if the IGBTs remain powered. This feature allows for mechanical work on the machine without needing to disconnect main power, reducing downtime. The drive also includes a comprehensive set of protection features: overcurrent, overvoltage, undervoltage, overtemperature, motor overload (electronic thermal), drive overload, ground fault, and output phase loss. All faults are logged in the fault history memory, retaining the last several faults with a time stamp and recorded current, voltage, and frequency at the moment of fault.

Easy PLC Functionality

The 3G3MX2-A4055-E includes an easy PLC function that can execute simple ladder logic programs to control auxiliary functions without needing an external PLC. The built-in programming allows up to 250 steps, with commands such as contacts, coils, timers, counters, arithmetic operations, and compare instructions. This feature is valuable for stand-alone machines where the drive also acts as a central logic controller, driving relays, reading sensors, and managing sequences such as a washing cycle or a belt grinder start/stop logic. The easy PLC can be programmed using the same software as the drive configuration, and it executes cyclically, typically every 2 to 8 milliseconds depending on program size.