E.OP fault in KEB COMBIVERT F5 Drive indicates an Over Voltage. This means the DC bus voltage rose above the permissible limit, typically due to regenerative motor energy or line voltage spikes.
Cause:
Elevated DC bus voltage. Common sources include:
- Motor regenerative operation (deceleration or overhauling).
- Transient voltage spikes from the mains supply.
- High line input voltage.
- Malfunctions in the DC bus voltage measurement circuit.
- High-frequency electrical noise.
Remedy:
The DC bus voltage LF.95 and the peak DC bus voltage LF.96 can be monitored.
- Braking Resistor Check: When using a braking resistor to dissipate regenerated energy, the braking resistor should come on at:
- 460V drives = 760VDC
- 230V drives = 380VDC
Ensure proper connection of the braking resistor to the braking transistor terminals PB, ++. Disconnect the braking resistor and measure resistance to verify if correct. Check the braking transistor if problems persist.
- Line Regen Unit Check: If a line regen unit is used, by default, the line regen unit will turn on at 103% of the idle DC bus voltage. Ensure proper connection between the drive and regen unit at the ++ and – – terminals at both units. Ensure the regen unit is regenerating properly, is in the regen status when required, and has no active faults preventing operation.
- Transient Spikes: If the over voltage is due to transient voltage spikes from the line, install a 3-5% line reactor.
- High Line Voltage: Step-down the line voltage using a transformer.
- Measurement Circuit or Noise Issues: Measure the DC bus directly and verify against the DC bus voltage read from the Diagnostics screen. The DC bus should measure approximately 1.41 x AC Input phase-to-phase. If there is high-frequency noise, verify proper mains grounding.
