The drive manual provides the following explanation:
The root cause is related to the power input to the drive. Based on customer feedback, the nr (Servo Not Ready) indication after power-on is the most commonly reported issue with the 1000W servo drive. In most cases, this is caused by the absence of power input to the main circuit of the drive.
As shown in the diagram below, the 1000W drive supports three-phase 220V input.
- L1C / L2C: Control circuit power input terminals
- R / S / T: Main circuit power input terminals
Many users inadvertently leave the R/S/T terminals unconnected, which causes the drive to display nr.
For reference, the diagram below shows the wiring configuration for single-phase 220V input to both the main and control circuits.
Note: Please verify whether your specific drive model supports single-phase input before proceeding with this wiring configuration.
Once the main and control circuit power connections are correct, the drive will display rd (Servo Ready).