Power Unit

What does F070 mean?

A critical failure has been detected within the drive's power section (e.g., rectifier, DC bus, inverter IGBTs). This indicates a significant internal hardware component failure that severely impacts the drive's ability to convert and deliver power to the motor. This usually requires component replacement or drive replacement.

• Failure of one or more IGBTs (Insulated Gate Bipolar Transistors) in the inverter section due to overcurrent, overvoltage, or thermal stress.
• Failure in the rectifier section (e.g., diode bridge) due to input voltage transients, sustained overvoltage, or internal defects.
• Issue with the DC bus capacitors, such as aging, overheating, or shorting, leading to instability or complete failure of the DC link.
• Internal short circuit within the drive's power stage, potentially caused by conductive contamination or component breakdown.
• Catastrophic internal component failure, often indicated by visible damage, burnt components, or a distinct smell.

Click steps to track your progress.

1. 1

   Immediately disconnect all input power to the drive and wait for the DC bus voltage (A0-06) to discharge to a safe level (< 50VDC).

2. 2

   Visually inspect the drive's internal power section (if safely accessible) for signs of burnt components, bulging capacitors, or discolored circuit boards.

3. 3

   Perform resistance checks across the input rectifier (L1/L2/L3 to DC bus +/DC bus -) and output IGBTs (DC bus +/DC bus - to U/V/W) using a multimeter (diode test mode). Look for shorts or open circuits.

4. 4

   Check all internal power connections for looseness or corrosion, especially to the IGBT modules and DC bus bars.

5. 5

   If internal damage is evident or multimeter tests confirm a short/open in the power section, the drive typically requires replacement or professional repair.

6. 6

   Before replacing, ensure the motor and motor cables are not shorted (check motor windings for resistance and insulation to ground, as per F038-F043 diagnostics).