Follow this systematic approach to diagnose and clear Yaskawa error code H66.
Perform a using the drive’s software tool (DriveWizard or similar) to visualize overshoot.
If a user runs an Advanced Auto-Tuning cycle or reverts the drive to factory defaults (via parameter A1-03) without reprogramming the custom pulse options, standard defaults can clash with pre-wired physical options cards or external encoders. Step-by-Step Resolution Guide yaskawa error code h66
[Power On Drive] ──> [Read Keypad Display: H66] ──> [Check Parameter H6-06] │ ┌───────────────────────────────────────────────────────┴──────────────────────────────────────────────────────┐ ▼ ▼ [H6-06 is set to 101, 102, 105, or 116] [H6-06 is set incorrectly] │ │ ▼ ▼ [Check Pulse Scaling Parameter] [Reprogram H6-06 value] │ │ ▼ ▼ [Change Value away from 0] ──> [Cycle Control Power] ──> [Verify ALM LED Clears] ───────────────────────> [Run Motor Test] Step 1: Verify the Configuration of H6-06 Stop all run commands to the drive.
Re-insert the card firmly into the slot, ensuring it seats evenly. Tighten the screws to secure it against vibration. Step 3: Check Shielding and Cable Routing Follow this systematic approach to diagnose and clear
Electrical noise from the AC power supply or grounding line can corrupt the communication between the drive and its operator, triggering intermittent "H" errors.
High-power motor cables running parallel to low-voltage communication or encoder lines generate significant electromagnetic fields. If your communication cables are unshielded or poorly grounded, this electrical noise corrupts the data packets, leading directly to an H66 sync failure. 3. Network Master or PLC Timeout Settings Step-by-Step Resolution Guide [Power On Drive] ──> [Read
Worn, pinched, or frayed cables connecting the control board to external modules often cause intermittent H66 errors.
If the H66 error persists after reseating the hardware, checking parameter configurations, and isolating electrical noise, the problem may stem from a failed internal component. In such cases, contact an authorized Yaskawa service center or your local distributor to test the option card or control board for hardware replacement.
[Determine Intent] ──> Is Pulse Output Scaling Needed? │ ├──> YES: Increase H6-07 value above 0 Hz │ └──> NO: Change H6-06 to an unscaled value (101, 102, 105, 116)
spike exactly when the motor receives a stop command.