Code 231-8680: DQ inverter %1: Maximum current limiting
Issue Description & Safety Warning
The Heidenhain TNC Series CNC has triggered a critical DQ inverter %1: Maximum current limiting alarm. Immediate attention from a qualified operator or maintenance technician is required to prevent secondary damage to the equipment or spoiled parts during the manufacturing cycle. Always ensure standard safety and LOTO procedures are followed before accessing electrical cabinets.
Official Troubleshooting Steps
[Cause of error] - The maximum current read from the inverter is smaller than the maximum current in the inverter table. - At a PWM frequency > 4 kHz: The output current has been derated too far. - The permissible load application of the inverter was exceeded. [Error correction] - Reduce the PWM frequency - Reduce the application load of the inverter - Inform your service agency
Source: HEIDENHAIN NC Error Messages — TNC7/640/620/320/128, CNC PILOT 640, MANUALplus 620 (10/2023)
Last reviewed: 2026-07-01 · Verified against the manufacturer’s official documentation.
About Heidenhain TNC Series CNC Alarms
Heidenhain controllers include extensive self-diagnostics that flag or halt the machine when a fault is detected. Error code 231-8680 on the TNC Series CNC identifies one specific fault condition — its documented cause and the official corrective steps are listed above, sourced from Heidenhain's service documentation. Always confirm against the manual for your exact machine configuration and follow LOTO procedures before servicing.
Complete Alarm List: 4497 Heidenhain TNC Series CNC codes.
Have a better solution?
Help the industrial community by sharing your repair experience for code 231-8680.
Need a searchable reference for more Heidenhain TNC Series CNC manuals?
We structure equipment manuals into searchable code, title, cause, solution, safety note, and source-reference data. Send a PDF and example searched codes when you need public pages, private search, or structured exports.
Space reserved for Google AdSense / Industrial Affiliate Links
Monetization target for 2026