Yaskawa A1000 AC Drive Common Fault Codes – Part 1

Yaskawa’s A1000 series AC Drive is a full featured drive, providing outstanding quality, performance, flexibility, and environmental friendliness through 1000HP. Enjoy network communications, feedback, and expandable I/O to control anything from simple fans and pumps to complex machines. For new installations or retrofits, the A1000 provides a single robust solution, regardless of your application.

Because the A1000 is such a valuable tool, it can be a headache when something goes wrong. With dozens of fault codes to parse and diagnose, it may be difficult to identify where your drive is encountering issues. To help you diagnose issues you’re having with the A1000, we’ve composed this guide to give you a head start when troubleshooting your drive.

This is Part 1 in a five-part series.



Baseblock Fault

When a baseblock fault occurs, the drive keypad will display “BB”

This is a warning and not so much a fault condition because it is set by a programmable input, S1 to S8 which ever input is configured for it.

Solution; Check external sequence and Baseblock signal input timing. This condition completely disables the drive’s output section from driving the motor (like a drive enable input). This is similar to Safe-off function built into other brands of modern drives. However, the difference is that SAFE-OFF is hard wired to a specific terminal on a drive dedicated to this function and interrupts control power to the Gate driver circuits of the output transistors (no software functionality involved). Baseblock is simply a software parameter configured to perform a similar function but does NOT have a dedicated input to do so.


Control Fault

When a control fault occurs, the drive keypad will display “CF”

This fault means s torque limit was reached continuously for three seconds or longer during a ramp to stop while in Open Loop Vector Control mode.


  1. Motor parameters are not set properly.
  2. Torque limit is set to low.
  3. Load inertia is too big.


  1. Check the motor parameter settings and repeat Auto-Tuning.
  2. Set the torque limit to the most appropriate setting (L7-01 through L7-04).
  3. Increase the deceleration time (C1-02, -04, -06, -08). Set the frequency to the minimum value and interrupt the run command when the drive finishes decelerating.


Stay tuned for Part 2! If you have any questions about the A1000 or drive fault codes, contact our experts today!


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