I have a pair of Yaskawa SGD7S-1R6A00A002 drives, SGM7A-02A7A21 motors (Sigma 7 series, 200W). At the moment I am bench testing a new setup, checking control-board to drive setup. The problem I am having is that as soon as the servo motor is enabled, the drives are emitting extremely annoying audible noise, at ~10.6kHz, and additionally creating substantial EMI, such that surrounding equipment (control board, laptop) functions poorly, if at all.
Details:
- The problem is only when the servo motor is enabled. Servodrive on, but motor not enabled there's no issue.
- If the servo is enabled but the motor isn't plugged in (drive doesn't seem to know this as long as encoder is hooked up), there's no noise or feedback.
- The motor power wiring is to spec, as far as I can tell (4-conductor 20AWG wire, shielded. Motor grounded, wire shield grounded).
- Motor power wiring is as short as I can make it (about 75cm). Originally was wired to my whole spool, ~4meters; reducing to 75cm seemed to make no difference.
- No tuning parameters seem to have any effect on this. The highest I can even set a notch filter is 5kHz.
- Motors seem to move fine, no noise/vibration. Movement or load have no discernable impact on the audible or EMI noise.
- Both drives do this, both motors do this.
- Drives are powered by 230V single phase, provided by step-up transformer from 115V mains (230V single phase is allowed for these drives, and the parameter for it has been set)
- I acquired both drives and motors used. Claimed to be off working machines, do seem to be in good shape.
Really hoping someone here can point me in the right direction with this issue! This is my first foray into servos, so I'll take no offense to any suggestion; there's every possibility that I've overlooked something basic. However I'm beginning to worry that this is just the way it is with these drives, which would render them very expensive, unusable hunks of metal.