AC servo drive
ACS Motion Control UDMhv servo drive
One- or two-axis EtherCAT drive module for 230 V or 400–480 V AC supplies, up to 20/60 A per axis, with up to four encoder channels and certified STO, for high-power stages.
Key specifications
| Data / bus | EtherCAT |
|---|---|
| Supply | 230 V AC or 400–480 V AC (185–525 V AC range) |
| Feedback | up to 4 channels: AqB, SinCos, absolute |
| Fieldbus | EtherCAT SubDevice |
| Axes | 1 or 2 |
| Continuous current (max) | 20 A |
| Peak current (max) | 60 A |
| Safe torque off | certified STO |
Summarised in our own words from PI Group (Physik Instrumente)'s published data; series maxima, individual models vary. Last checked 2026-10-30. Source 1 · Source 2
Notes on this data
Current pairs not labelled continuous/peak by ACS.
Specify Motion is not affiliated with PI Group (Physik Instrumente). ACS Motion Control and UDMhv are used only to identify the product. Comparisons use published figures; always confirm against the current datasheet.
Typical applications
Alternatives that meet or exceed these figures
Engineers often come to us with an ACS Motion Control part number and leave with an alternative that is easier to source, quicker to deliver or a better fit for the machine. These 3 series from our supply network are the closest match on published figures.
Leadshine's EL7 platform spans 220 VAC drives from 400 W to 2 kW, 400 VAC drives to 7.5 kW and an 11-22 kW high-power range, all with STO and EtherCAT, Modbus/pulse or PROFINET variants.
| Published maximum | UDMhv | EL7S / EL7 Series AC Servo Drives |
|---|---|---|
| Continuous current | 20 A | 44 A meets or exceeds |
| Peak current | 60 A | 88 A meets or exceeds |
| Power | — | 22,000 W |
| Axes | — | 1 |
The second-generation Kinco JD drive, paired with SMK motors from 50 W to 7.5 kW. It accepts a very wide range of encoder protocols plus a second encoder, runs CANopen or EtherCAT, and has STO SIL3 / PL e on every model.
| Published maximum | UDMhv | JD2 Series AC Servo Drives |
|---|---|---|
| Continuous current | 20 A | 26 A meets or exceeds |
| Peak current | 60 A | 65 A meets or exceeds |
| Power | — | 7,500 W |
| Axes | — | 1 |
Kinco's new-platform AC servo drive for SMK motors, 400 W-7.5 kW on 220 or 380 V, with 17/23-bit absolute encoder support and RS485, EtherCAT or PROFINET variants.
| Published maximum | UDMhv | FD5P (PRO) Series AC Servo Drives |
|---|---|---|
| Continuous current | 20 A | 26 A meets or exceeds |
| Peak current | 60 A | 65.06 A meets or exceeds |
| Power | — | 7,500 W |
Figures are the highest published for each series and are not always measured the same way. A higher figure is not automatically a better choice: mounting, duty cycle, feedback, connectors and approvals matter too. An engineer will check the fit against your application before recommending anything.
What an AC servo drive is
An AC servo drive, or servo amplifier, powers and controls a servo motor from mains supply. It rectifies the AC input to a DC bus, then uses an inverter of power transistors switched by PWM to produce controlled three-phase current in the motor. Nested current, velocity and position loops use encoder feedback to follow commands from pulse and direction, analogue or industrial Ethernet. Modern drives add auto-tuning, vibration suppression and safety functions such as safe torque off.
When engineers choose an AC servo drive
Choose an AC servo drive for mains-powered machines with servo axes from tens of watts to many kilowatts, such as packaging, machine tools and robotics. It gives precise, dynamic control with standard industrial interfaces. The trade-offs are cabinet space, wiring, EMC measures and the need to match motor and feedback. For low-voltage or mobile machines, a DC drive is more suitable; for many axes in one cabinet, a multi-axis drive may save space.
How to specify the ACS Motion Control UDMhv
Send these with your enquiry and an engineer can confirm the right UDMhv variant or an equivalent:
- Supply voltage and phases (V AC)
- Continuous and peak output current (A rms)
- Motor and feedback compatibility
- Command interface: pulse, analogue, EtherCAT, PROFINET and so on
- Safety functions, such as STO, and their rating (SIL, PL)
- Braking resistor and regenerative energy (W, J)
- Ambient temperature, mounting and cooling
Common mistakes to avoid
- Sizing on motor rated current without the drive's peak duration
- Ignoring regenerative energy on fast decelerations or vertical axes
- Leaving out EMC filtering and screened motor cables
- Mixing motor and encoder types the drive does not support
ACS Motion Control UDMhv: frequently asked questions
What is the ACS Motion Control UDMhv?
One- or two-axis EtherCAT drive module for 230 V or 400–480 V AC supplies, up to 20/60 A per axis, with up to four encoder channels and certified STO, for high-power stages. Published series figures include continuous current 20 A, peak current 60 A. It is made by PI Group (Physik Instrumente); Specify Motion can help source it or propose an equivalent.
Who makes the ACS Motion Control UDMhv?
The ACS Motion Control UDMhv is made by ACS Motion Control (PI Group (Physik Instrumente)) and is listed here for engineers comparing options. Specify Motion is not affiliated with PI Group (Physik Instrumente); brand names are used only to identify the product.
What is the continuous current of the ACS Motion Control UDMhv?
The published series maximum continuous current is 20 A. Individual models and sizes in the UDMhv range vary, so check the exact variant against your duty cycle, mounting and environment, or ask our engineers to confirm the right size for you.
Is there an alternative to the ACS Motion Control UDMhv?
Yes. On published figures, Leadshine EL7S / EL7 Series AC Servo Drives and Kinco JD2 Series AC Servo Drives are the closest match from our supply network. An engineer confirms the fit against your application before recommending anything.
Does a servo drive need a braking resistor?
When a servo motor decelerates, it acts as a generator and returns energy to the drive's DC bus. If the bus capacitors cannot absorb it, the voltage rises and the drive trips. A braking resistor dissipates the energy as heat. Fast decelerations, high inertia and vertical axes usually need one.
What is safe torque off on a servo drive?
Safe torque off, or STO, is a safety function that removes power that could produce torque at the motor, without disconnecting the drive supply. It is defined in IEC 61800-5-2 and used as part of a machine's safety system. Check the safety level achieved and wiring requirements.
Further reading: How to select a servo drive · How to select a servo motor · Servo drives
Other ac servo drive series
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