IndustrialDriveDataDrive Board & Diagnostic Database
Input rectifier / DC-link / braking

PowerFlex Input, DC Bus and Dynamic Brake Path

Routes F4 and F5 evidence through input phases, fuses/contactors, precharge, DC-link capacitors, brake chopper/resistor, load inertia and line voltage.

Functional path

L1/L2/L3 input
Fuses / contactor
Precharge
Rectifier
DC-link capacitors
Brake chopper
Dynamic brake resistor

Diagnostic signals and checkpoints

F4F5Input voltageDC bus trendDecel timingBrake path condition

Technician notes

  • Overvoltage during deceleration is a regeneration/braking question before it is a control-board question.
  • Undervoltage must be measured at the drive terminals under realistic plant load.