What to state in the enquiry
State the work with the enquiry — the diameter range, facing and heavy cuts, and any threading duty — together with the motor data, and ask for the documented figures for the model to be stated in the quotation.
The published AU720 figures
- Low-speed torque: 150% starting torque at 0.25 Hz in sensorless vector (SVC) mode, as published for the AU720.
- Speed range: 1:200 in SVC, as published for the AU720.
- Speed holding: ±0.5% steady-speed precision in SVC, as published for the AU720.
- Overload capacity: 150% of rated output current for 1 min, as published for the AU720.
The AU720 also publishes a closed-loop mode (FVC: 1:1000 speed range, ±0.02% steady precision, 180% starting torque at 0 Hz), covered on the closed-loop VFD page. See also the AU720 page.
The published AU720 overload structure behind those figures is 150% of rated output current for one minute, with the carrier frequency auto-adjusted against load characteristics. The AU720 input classes are published too — 380 V class ±15% (actual range 323–437 V) and 220 V class ±15% (187–253 V) — the input classes published for the AU720 series. The series' protection list is also published: overcurrent, overvoltage, undervoltage, module fault, electric thermal relay, overheating, short circuit, input and output phase loss, motor parameter abnormalities and internal memory faults.
Stopping the spindle
The AU720 documents a built-in braking unit at 18.5 kW and below. State the chuck and workpiece mass range in the enquiry if short, controlled stops matter to the work. Above 18.5 kW, ask for the braking configuration for the model to be stated in the quotation.
If the work involves long low-speed heavy cuts, state that duty profile in the enquiry and ask for the configuration for it to be addressed in the quotation.
Frequently asked questions
Can a VFD replace the back gear on an old lathe?
That is a machine-by-machine judgement, not a catalogue claim. The published figures to compare against the work are the AU720's 1:200 SVC speed range and 150% starting torque at 0.25 Hz. Send the motor data and the work envelope with your enquiry, and ask for the comparison to be made for your machine.
Send us your motor rating and application
Tell us the motor power, the supply voltage on site and what the drive will run — pump, fan, machine tool or lift. Minimum order is 1 piece on the main catalogue lines, as published on the platform store; ask for price and lead time for your model and quantity to be stated in the quotation. Email [email protected] or message us on WhatsApp.