Undervoltage Fault (Controlled Stop, Adv. Code 2)

What does F32 mean?

This fault occurs when the drive detects an undervoltage condition and is configured for 'Controlled' power loss response via parameter 525. The drive decelerates the motor while attempting to regulate the bus voltage, but faults if it reaches a stopped condition. This signifies a sustained undervoltage that exceeds the drive's ride-through capability, leading to a controlled shutdown.

• Input supply voltage dropping below the drive's undervoltage trip threshold (e.g., 340V for a 400V drive) during a power sag, despite P5-25 (Controlled Stop) activation.
• Energy regeneration into the DC bus (from a decelerating motor) is insufficient to maintain voltage during a deep voltage dip when P5-25 is active.
• DC bus capacitors nearing end-of-life, reducing their ability to store energy for ride-through during a controlled stop.
• Heavy dynamic braking or rapid deceleration demanding more energy than the supply can provide, combined with an existing input voltage drop.

Click steps to track your progress.

1. 1

   1. Measure input line voltage (L1-L2, L2-L3, L3-L1) at the drive's input terminals during operation, especially when a controlled stop is initiated or during power transients.

2. 2

   2. Verify Parameter P5-25 (Controlled Stop setting) is configured appropriately for the application's inertia and power loss requirements.

3. 3

   3. Check all connections at the drive's input terminals and main disconnect switch for looseness or corrosion that could cause voltage drop.

4. 4

   4. Reduce the deceleration rate (P1-11) or extend the controlled stop time to allow for a slower energy discharge from the DC bus.

5. 5

   5. Consider adding an external DC bus capacitor bank (if drive supports) or a line reactor to mitigate voltage sags and improve ride-through capability.