RX-A4055-EF Variable Frequency Drive RX 5.5kW 3-ф/380

Omron RX-A4055-EF — 5.5 kW, 3-ph 400V

A 3G3RX model rated 5.5 kW, 3-phase input 380…480V, 3-phase 400V output, rated input current about 14 A. A high-function drive: V/f, sensorless vector and sensor vector with an encoder card for precise torque/speed in lifting and winding jobs.

Often found on mid-power pumps, fans, crushers and conveyors. Built-in braking transistor (external resistor), built-in EzSQ logic, RS485 Modbus, frequency up to 400 Hz, 150%/60s overload, IP20. EMC filter is external (option). A from-stock replacement in this class is the Veichi AC310.

Omron RX (3G3RX) variable frequency drives: the high-function series

Omron RX (factory code 3G3RX) is not a compact budget drive — it is a high-function general-purpose series for jobs where an ordinary micro drive runs out of dynamics: hoists and cranes, winders, positioning, machine tools, high-inertia fans and pumps. Our line-up covers the 3-phase 400V class from 0.7 to 22 kW (input 3-ph 380…480V, 50/60 Hz).

What sets RX apart from compact series

• Closed-loop vector. Besides V/f and sensorless vector, RX supports sensor (closed-loop) vector control with an encoder card (parameter A044=05). Using encoder feedback the drive holds high torque and speed precision across the whole range — something micro drives cannot do.
• 150% starting torque at 0.3 Hz in sensorless vector and 200% torque at 0 Hz — for lifting gear and heavy starts.
• Built-in EzSQ (Drive Programming) logic block. Simple sequences and logic can be embedded directly in the drive, with no external PLC.
• Built-in braking transistor (chopper) on all models up to and including 22 kW — only an external braking resistor is needed. Above 22 kW the series requires a separate regenerative braking unit.

Control, communication, protection

Overload 150% for 60 s and 200% for 3 s (heavy duty), maximum output frequency up to 400 Hz. A built-in RS485 Modbus port is standard; DeviceNet, PROFIBUS-DP, EtherCAT and other buses are available via optional network cards. IP20 enclosure for panel mounting. The EMC filter on RX is external (option) — match it by part number to your required EMC level.

Sizing and service notes

RX is a legendary but mature-generation series. Size the drive by motor current and duty (CT/heavy or VT/light), not by kilowatts alone: for a crane or winder, allow headroom and set up sensor vector with an encoder. If you need a current-generation drive of the same class with local stock and support, see our Veichi AC310 (general-purpose vector), and for simpler pump/fan tasks the Veichi AC10. Have a 3G3RX and unsure about a replacement? Send us the model and motor current and we will suggest an analog matched by wiring and terminals.