Power unit: DC link voltage, overvoltage

What does 230502 mean?

This fault indicates that the power unit has detected an overvoltage condition in the DC link, leading to a pulse inhibit. Common causes include a device supply voltage that is too high or an incorrectly dimensioned line reactor, as indicated by the fault value in r0949. Persistent DC link overvoltage can damage power electronic components, reduce drive lifespan, and lead to complete drive failure if not corrected.

• Excessive regenerative energy from a decelerating motor (e.g., high inertia load stopping quickly) exceeding the drive's braking capacity.
• Braking resistor (if installed) is incorrectly sized (too high resistance), faulty (open circuit), or its connection (e.g., X2 terminals) is loose.
• Incoming line supply voltage (e.g., L1, L2, L3) is consistently above the drive's nominal input voltage tolerance (e.g., >480V for a 400V drive).
• Incorrect setting of the DC link overvoltage threshold parameter (e.g., P2170) making the drive overly sensitive.
• Failure of internal DC link voltage measurement circuitry within the power unit.

Click steps to track your progress.

1. 1

   1. Measure the incoming line voltage (L1-L2, L2-L3, L3-L1) at the power unit input terminals to ensure it is within the specified range (e.g., 380-480VAC).

2. 2

   2. Measure the resistance of the external braking resistor (e.g., between X2 terminals) and compare it to the specified value in the drive manual.

3. 3

   3. Check the wiring and connections of the braking resistor to the power unit terminals (e.g., X2) for looseness or corrosion.

4. 4

   4. Adjust the deceleration ramps (e.g., P1121, P1135) to be slower, allowing for less regenerative energy generation.

5. 5

   5. Verify parameter P2170 (DC link overvoltage threshold) against the nominal DC link voltage (e.g., 1.35 * nominal line voltage).