Charging switch

What does 5 mean?

The internal charging switch, which is responsible for pre-charging the DC-link capacitors, remains open when a START command is given. This indicates either an operational malfunction or a defective internal component within the drive. If this fault persists, the drive will be unable to start and operate, signaling a serious internal hardware issue.

• Failure of the internal pre-charge resistor or contactor (if applicable) to close, preventing the DC-link from charging.
• Low incoming AC supply voltage preventing the DC-link from reaching the pre-charge threshold within the allowed time.
• Internal control board fault preventing the command signal from reaching the charging switch circuit.
• Defective DC-link capacitors preventing them from holding a charge, or excessive leakage.
• High inrush current caused by external factors preventing the charging circuit from stabilizing.

Click steps to track your progress.

1. 1

   Measure the incoming AC supply voltage at the drive input terminals (L1, L2, L3) using a true RMS multimeter to ensure it is within the specified operating range (e.g., 380-480VAC).

2. 2

   With power off and safely discharged, inspect the internal charging circuit components (resistors, contactors/relays) for visible damage, arcing, or loose connections.

3. 3

   Attempt a power cycle (turn mains power off for 60 seconds, then on) to reset internal logic and observe if the fault clears.

4. 4

   Measure the DC-link voltage (e.g., terminals DC+ and DC-) immediately after power-up to confirm it attempts to rise during the pre-charge sequence.

5. 5

   If available, use the drive's diagnostic tools (e.g., parameter A5-01 for DC-link voltage) to monitor the pre-charge process.