Code P10-10129: I1 DC Bus Imbal
Issue Description & Safety Warning
The Allen-Bradley PowerFlex 750 Drive has triggered a critical I1 DC Bus Imbal 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
Type: Resettable Fault Coast Either the lower or upper leg of the capacitor bank is getting too much voltage (based on the bus voltage, measured voltage across the lower leg, and a calculation to find the voltage across the upper leg) or the voltage sensing components are damaged. • Check the value of the bus bleeder resistor and bus balancing resistor and replace as necessary. • Inspect the capacitor bank for leakage or damage and replace as necessary. Replacing the capacitor bank assembly also replaces the bus balancing resistor. • Measure the voltage on each half of the bus to confirm the calculations. If the bus measurements aren’t correct, replace the power interface board and/or inverter power supply board.
Source: Allen-Bradley PowerFlex 750-Series AC Drives Programming Manual (750-PM001)
Last reviewed: 2026-07-01 · Verified against the manufacturer’s official documentation.
About Allen-Bradley PowerFlex 750 Drive Alarms
Allen-Bradley controllers include extensive self-diagnostics that flag or halt the machine when a fault is detected. Error code P10-10129 on the PowerFlex 750 Drive identifies one specific fault condition — its documented cause and the official corrective steps are listed above, sourced from Allen-Bradley's service documentation. Always confirm against the manual for your exact machine configuration and follow LOTO procedures before servicing.
Complete Alarm List: 663 Allen-Bradley PowerFlex 750 Drive codes.
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