Over-voltage Protection

What does E07 mean?

This fault occurs when the DC bus voltage inside the inverter exceeds a predefined safe threshold. This usually happens during deceleration due to regenerative energy from the motor returning to the drive faster than it can be dissipated, or from an unstable input power supply.

• Deceleration time (Parameter P1-11) set too short for the load's inertia, causing rapid regeneration of energy into the DC bus.
• Braking resistor (Parameter P2-01) not connected, incorrectly sized, or failed open, preventing energy dissipation.
• Braking transistor (internal or external) malfunction, failing to activate and shunt regenerative current.
• Abnormally high input AC supply voltage at inverter terminals L1, L2, L3, leading to an elevated DC bus voltage baseline.
• Sudden loss of load or rapid changes in load inertia during operation, causing the motor to act as a generator.

Click steps to track your progress.

1. 1

   Increase Deceleration Time (Parameter P1-11) by 20-50% to allow for slower energy dissipation.

2. 2

   Verify the connection and resistance of the external braking resistor (terminals P1, PB) using a multimeter; compare to specified ohmic value.

3. 3

   Monitor the DC bus voltage (display parameter d0-02) during deceleration; if it rapidly exceeds the over-voltage threshold (e.g., 800V for 400V class), check braking circuit.

4. 4

   Measure the input AC voltage at inverter terminals L1, L2, L3 using a multimeter to confirm it is within the inverter's specified range.

5. 5

   Activate or adjust the 'Over-voltage suppression' function (e.g., Parameter P7-03) to automatically extend deceleration time.