DC Bus Overvoltage

Hva betyr DC Overvoltage ?

The DC bus voltage inside the drive has risen beyond its acceptable operating limit. Common causes include excessively short deceleration times, disabled stall prevention, a malfunctioning braking chopper or resistor, unstable motor control, or an excessively high input voltage. This condition poses a risk of damage to the drive's internal DC link capacitors and power components.

• Deceleration time (e.g., P1-06) is set too short for the inertia of the load, causing excessive regenerative energy.
• Braking resistor (if installed) is incorrectly sized (too high resistance), disconnected, or its braking chopper circuit (internal or external) has failed.
• 'Stall Prevention (Decel)' function (e.g., L3-04) is disabled or set too low, preventing the drive from extending deceleration time.
• High inertia load application experiencing rapid speed reduction, overpowering the drive's regenerative braking capacity.
• Input supply voltage (e.g., L1, L2, L3) is intermittently or continuously too high, exceeding the drive's nominal input voltage range (e.g., 400V).

Klikk på steg for å spore fremgangen.

1. 1

   1. Increase the deceleration time parameter (e.g., P1-06) by at least 20% to allow for slower energy dissipation from the load.

2. 2

   2. Enable and properly configure the 'Stall Prevention (Decel)' function (e.g., L3-04) to allow the drive to automatically extend deceleration time and prevent overvoltage.

3. 3

   3. If a braking resistor is installed, verify its resistance value with an ohmmeter (e.g., X ohms) matches the drive's specifications and check wiring to terminals (e.g., B1, B2).

4. 4

   4. Check the functionality of the internal or external braking chopper. Monitor the DC bus voltage (U1-03) during deceleration to see if the chopper activates.

5. 5

   5. Measure the incoming AC line voltage (e.g., between L1-L2, L2-L3, L3-L1) with a multimeter to ensure it is within the drive's specified operating range.

6. 6

   6. For high inertia loads, consider installing an appropriately sized external braking resistor and chopper if not already present, or increasing the existing one's capacity.