Home > RA3 Servo Drive
| Item | Specifications |
|---|---|
| Series | RA3 AC Servo Drive |
| Control Method | IGBT PWM, sine-wave current drive |
| Rated Current | 1.6A – 45A |
| Input Voltage | 1-ph 220V / 1-3 ph 220V / 3-ph 220V / 3-ph 380V |
| Encoder Type | Communication encoder (RS485) |
| Control Modes | Position, speed, torque |
| Protection | IP20 |
| Ambient Temperature | 0 ~ 55°C (derate above 45°C) |
| Frame Sizes | Size A to F |
| Input Voltage | Rated Current Range | Current Steps |
|---|---|---|
| Single-phase 220V | 1.6 – 6.6 A | 1.6 / 2.8 / 5.5 / 6.6 A |
| Single / three-phase 220V | 7.6 – 12 A | 7.6 / 12 A |
| Three-phase 220V | 18 – 27 A | 18 / 22 / 27 A |
| Three-phase 380V | 3.5 – 45 A | 3.5 / 5.4 / 8.4 / 12 / 16.5 / 21 / 25.7 / 32 / 38 / 45 A |
*Rated current is selected to match the servo motor. Model code example: RA3 E - 5R5 L (series - control method - current - input voltage). We supply the drive matched and tested with the motor.
The RA3 is our full-range AC servo drive series, an AC servo motor driver for industrial motion. It uses IGBT PWM sine-wave current control with a communication-type (RS485) encoder interface, and covers rated currents from 1.6A to 45A across 220V and 380V supplies. It runs position, speed, and torque modes, and is built to pair with our AC servo motors as a matched, tested set.
The RA3 comes in three control versions, set by the model code: E is EtherCAT (bus control), P is pulse, and A is pulse plus analog command. Choose E for networked multi-axis machines, P for simple pulse/direction control, and A when you also need an analog speed or torque reference.
Rated current runs from 1.6A to 45A. The supply options are single-phase 220V (1.6–6.6A), single/three-phase 220V (7.6–12A), three-phase 220V (18–27A), and three-phase 380V (3.5–45A). The 380V band carries the largest models, so the RA3 reaches higher power than the RS3 series.
The EtherCAT version (RA3E) follows IEC 61158 Type12 and IEC 61800-7 CiA 402, with 100BASE-TX dual RJ45 ports, a 100Mbps line, and a 250µs–10000µs cycle. It supports CiA 402 modes PP, PV, PT, HM, CSP, CSV, and CST. The pulse versions use RS485 Modbus, and the A version adds CANopen. A USB Type-C port is provided for PC tuning on all models.
Protection covers over-voltage, under-voltage, phase loss, over-current, overload, over-speed, and encoder disconnection. A dynamic brake acts on power loss, alarm, servo-off, and over-travel, and regenerative braking is built in on all but the smallest Size A models. STO is available as an option, along with full-closed-loop and high-protection variants.
The RA3 is the full-range, higher-power series: 1.6A to 45A, including three-phase 220V and the large 380V models, with CANopen on the analog version. The RS3 is the compact series, 1.6A to 12A, for small and mid-size axes. Both share the same control platform and encoder interface; see the rs3-servo-drive page for the compact option.
Yes. As an AC servo drive manufacturer and supplier, we provide the RA3 drive sized and tuned to the servo motor as a tested set, so the current rating, commutation, and gains are configured before delivery. The drive ships ready to run with the matched motor.
The RA3 servo drive is our full-range AC servo drive series, covering rated currents from 1.6A to 45A across single-phase 220V, three-phase 220V, and three-phase 380V supplies. It uses IGBT PWM sine-wave current control with a communication-type (RS485) encoder interface, and comes in EtherCAT, pulse, and pulse-plus-analog versions. Because it reaches the large 380V models, the RA3 is the higher-power choice in our drive line, pairing with servo motors from the small 60mm frame up to the large 180mm. Every RA3 ships matched and tested with its motor.
| Parameter | Specification |
|---|---|
| Series | RA3 AC servo drive |
| Rated Current | 1.6 – 45 A |
| Input Voltage | 220V / 380V (1-ph and 3-ph) |
| Control Method | IGBT PWM, sine-wave current |
| Control Versions | E (EtherCAT), P (pulse), A (pulse + analog) |
| Encoder Interface | Communication encoder (RS485) |
| Control Modes | Position, speed, torque |
| Protection Rating | IP20 |
The RA3 model code sets the control method, so one series covers most machine architectures:
The EtherCAT version uses 100BASE-TX over dual shielded RJ45 ports at 100Mbps, with a 250µs to 10000µs cycle and DC synchronization. It supports CiA 402 modes PP, PV, PT, HM, CSP, CSV, and CST, so it drops into standard EtherCAT motion controllers. The pulse versions communicate over RS485 Modbus for parameter setup, and a USB Type-C port is provided on every model for PC tuning software.
Every RA3 drive includes a full protection set — over-voltage, under-voltage, phase loss, over-current, overload, over-speed, and encoder disconnection. A dynamic brake engages on power loss, alarm, servo-off, and over-travel, and regenerative braking is built in on all but the smallest Size A models. Optional functions, set in the model code, include STO (safe torque off), full-closed-loop control (F), the full-function package (FS), and a high-protection build (HP).
The RA3 suits a broad range of industrial motion, from small benchtop axes to large machines:
Both share the same control platform and encoder interface. The difference is power coverage:
| RA3 | RS3 | |
|---|---|---|
| Rated Current | 1.6 – 45 A | 1.6 – 12 A |
| Input Voltage | 220V / 380V | 220V / 380V |
| Control Versions | E / P / A | E / P |
| Best For | Full range, higher power | Compact, small to mid axes |
Choose the RA3 when you need the full current range, higher-power 380V models, or the analog (A) version. For small to mid-size axes in a compact package, see the RS3 servo drive. Both pair with our AC servo motor range as a matched set.
The RA3 model code reads series – control method – rated current – input voltage – option. For example, RA3E-5R5L is an RA3 EtherCAT drive, 5.5A, single-phase 220V. Current ratings use the R notation (5R5 = 5.5A, 12R = 12A). As the factory, we help you select the right code against your motor and supply, support custom configurations for OEM projects, and ship the drive matched and tested with the motor.
