Code oH3 (Fault): Motor Overheat Alarm (PTC Input)
Issue Description & Safety Warning
The Yaskawa A1000 AC Drive has triggered a critical Motor Overheat Alarm (PTC Input) 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
Code type: Fault Manual section: Yaskawa A1000 Troubleshooting Motor has overheated - Check the size of the load, the accel/decel times, and the cycle times. - Decrease the load. - Increase the acceleration and deceleration times (C1-01 through C1-08). - Adjust the preset V/f pattern (E1-04 through E1-10). This will mainly involve reducing E1-08 and E1-10. - Be careful not to lower E1-08 and E1-10 too much, as this reduces load tolerance at low speeds. - Check the motor rated current. - Enter the motor rated current as indicated on the motor nameplate (E2-01). - Ensure the motor cooling system is operating normally. - Repair or replace the motor cooling system.
Source: Yaskawa AC Drive A1000 High Performance Vector Control Drive Technical Manual (SIEP C710616 21H)
Last reviewed: 2026-07-01 · Verified against the manufacturer’s official documentation.
About Yaskawa A1000 AC Drive Alarms
Yaskawa controllers include extensive self-diagnostics that flag or halt the machine when a fault is detected. Error code oH3 (Fault) on the A1000 AC Drive identifies one specific fault condition — its documented cause and the official corrective steps are listed above, sourced from Yaskawa's service documentation. Always confirm against the manual for your exact machine configuration and follow LOTO procedures before servicing.
Complete Alarm List: 280 Yaskawa A1000 AC Drive codes.
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