PowerFlex 4 F005 Overvoltage on Decel with High-Inertia Load?
I'm getting an F005 fault on my PowerFlex 4 drive, specifically during deceleration. It's connected to a high-inertia load. What should I check first to resolve this overvoltage trip?
An F005 fault on a PowerFlex 4 drive indicates an overvoltage condition on the DC bus. When this happens during deceleration, it's usually due to regenerative energy from the motor exceeding the drive's ability to dissipate it. The most common causes are a decel time that's too short for the load or issues with dynamic braking.
Likely causes and checks
1Decel time too short for load inertia
- Points to it
- The drive trips only during stops or speed reductions, especially with heavy or high-inertia loads. The DC bus voltage display will show a high value at the time of the trip.
- Check
- Increase the deceleration time ([Decel Time 1]) in small steps and watch the DC bus voltage display during the next stops to see that it stays below the trip level. Parameter numbers differ between PowerFlex 4, 40 and 525, so look them up in your drive's manual.
2Bus regulator disabled or ineffective
- Points to it
- The drive trips during deceleration and the bus regulator is turned off, or a dynamic braking resistor is fitted but not selected in the drive.
- Check
- Check that the bus regulator is enabled, and if a dynamic braking resistor is fitted, that it is selected in the drive's DB resistor parameter. With power isolated and locked out, inspect the resistor wiring and measure its resistance.
3Overhauling or eccentric load
- Points to it
- The drive trips while running at steady speed, particularly with loads that tend to drive the motor (e.g., lowering, downhill, or cam-type applications).
- Check
- Determine if the load is driving the motor. If so, a dynamic braking resistor may be required, sized according to the drive's manual for the specific application.
4High incoming line voltage or transients
- Points to it
- The drive trips at constant speed or even while stopped. These trips might coincide with other electrical events on the supply line, such as capacitor switching.
- Check
- Measure the incoming AC line voltage to the drive and log it over time to identify any high voltage conditions or transient spikes.
Next check: If longer decel times and the bus regulator do not stop the trips, and the load is regenerative, size and fit a dynamic braking resistor as the drive's manual describes.
What it typically looks like in the data
Related questions
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