Scope of this technical record
Workflow for overcurrent trips at enable, first PWM, acceleration or early run.
Avoid repeated resets. Isolate and discharge before output wiring, motor or module checks, and follow OEM procedure for any disconnected-motor test.
Overcurrent workflow route
The workflow prevents repeated reset attempts from becoming repeated semiconductor failure.
Startup overcurrent workflow image
Workflow goal
Startup overcurrent pages often flatten the problem into load or IGBT. This workflow is built around timing: enable, first PWM, acceleration, speed threshold or loaded run. Timing determines whether the first evidence is machine/load, motor/cable, parameter/feedback or drive hardware.
Timing-to-boundary table
Record the exact point of trip before changing parameters or replacing hardware.
Startup overcurrent workflow
| Trip timing | First boundary | Escalation |
|---|---|---|
| At run command before rotation | Enable logic / immediate output path | Check output accessories and driver evidence |
| At first PWM | Motor/cable or inverter bridge | Separate external path from output stage |
| During ramp | Load/ramp/motor data | Review acceleration, torque demand and feedback |
| At specific speed | Mechanical resonance/load | Review machine and control mode |
| After module replacement | Driver/current feedback | Stop until pre-power checks are complete |
Repair boundary
Only after external output, machine load and parameter evidence are clean does the workflow move to driver supplies, gate components, current feedback and the power module.
Field record checklist
- Trip timing
- Motor/cable status
- Acceleration and motor data
- Load condition
- Control mode and feedback
- Previous module repair
Technical basis and reference documents
This is an independent editorial technical reference. Original manufacturer documentation remains controlling for installation, repair and commissioning decisions.
Circuit path for output-stage escalation.
Linked records
Immediate overcurrent can be caused by load lock, motor/cable fault, wrong motor data, current-sensing error, gate-driver failure or a damaged output bridge. The trip text alone does not identify the failed component.
The route must separate motor lead, contactor, current sensor, gate-driver command and output power device evidence.
Repeat module failure usually means the original cause was not limited to the module; gate-drive, isolated supply, current detection, snubber/clamp, motor cable or load evidence must be reviewed.
Connects PWM command, isolated driver supply, gate components, short-circuit protection and the output bridge to overcurrent and repeat-module-failure symptoms.
Separates motor insulation, cable leakage, terminal contamination, output filters and internal sensing when a drive trips only after output voltage is applied.
Turn this record into a qualified service request
A repair decision is much more reliable when the request includes the exact identity of the drive, the first fault evidence and the machine condition when the symptom appeared.
- Complete drive type code / MLFB or nameplate model
- Fault code, fault value and first event before reset
- When the event appears: power-up, enable, ramp, run, decel or stop
- Motor/cable connected or isolated during the symptom
- Visible board, option-card, module and connector identifiers
- Previous repair history, replacement parts and repeat-failure pattern