DC OVERVOLT

What does 3210 mean?

Excessive intermediate circuit DC voltage, exceeding the trip limit (e.g., 728 V DC for 400 V units). This fault often occurs during rapid deceleration of high inertia loads or due to problems with the braking system, posing a risk of damage to the drive's power components.

• Regenerative energy from a rapidly decelerating high-inertia load exceeding the drive's ability to dissipate it (e.g., braking resistor missing or undersized).
• Drive deceleration time (P2-02) set too short for the inertia of the connected mechanical system.
• Failure of the braking chopper circuit or associated external braking resistor, preventing energy dissipation.
• Excessively high incoming AC line voltage (L1-L2, L2-L3, L3-L1) feeding the drive, causing the DC bus to rise above nominal.
• Faulty DC bus voltage measurement circuit within the drive, providing an inaccurate high reading.

Click steps to track your progress.

1. 1

   1. Measure the actual DC bus voltage at the drive's intermediate circuit terminals (DC+, DC-) using a high-voltage multimeter.

2. 2

   2. Increase the drive's deceleration ramp time (P2-02) to allow for slower speed reduction and less regenerative energy.

3. 3

   3. Verify the presence, resistance (e.g., 20 Ohms), and connection of the external braking resistor and test the internal/external braking chopper.

4. 4

   4. Measure the incoming AC line voltage (L1-L2, L2-L3, L3-L1) at the drive's input terminals, ensuring it is within the drive's specified range.

5. 5

   5. If a braking resistor is present, check its thermal switch (if applicable) for continuity and reset if tripped.