Investigation sequence
Classify timing
Separate instant start trip, acceleration trip and load-only trip; each changes the likely boundary.
Check machine and parameter evidence
Inspect mechanical blockage, load condition, acceleration time and motor-nameplate parameter entry.
Check output path
Inspect motor cable, terminal box, output contactors and output accessories that should not be connected to a VFD output.
Evaluate power-stage evidence
If the external path is credible, check IGBT/IPM, gate driver and current feedback before power-up.
Prepare a support request
Include whether the motor was connected, trip timing, nameplate data, parameter changes and any module repair history.
Stop conditions
- Unknown motor insulation condition
- Previous module replacement without driver checks
- Trip occurs instantly after every reset
- Mechanical load cannot be safely decoupled
Linked records
The output current is excessive or being measured as excessive. The diagnosis must separate motor/load/cable causes from acceleration settings, encoder/feedback issues and inverter power-stage damage.
Organizes reference voltage, analog input, digital input, relay output and auxiliary 24 V terminal evidence for start/stop, direction, speed-reference and external-fault issues.