nSt on ATV630: check the stop command
The ATV630 FAQ describes a case of free wheel stop in three-wire control: the opening of the stop entry leads to nSt. It should be read the real configuration, not applied a universal scheme.
The case in 60 seconds
The ATV630 FAQ describes a case of free wheel stop in three-wire control: the opening of the stop entry leads to nSt. It should be read the real configuration, not applied a universal scheme.
Transcribe nSt and indicate the local/remote mode and the control mode of the machine.
The code or symptom directs research, but does not show the fault component alone.
Diagnostic map
Follow the rows in order. Each phase must produce evidence before moving to the next.
| Phase | Controls | Evidence to obtain | Next decision |
|---|---|---|---|
| 01Recognize and collect |
| Event context and complete initial data. | If a data is missing, do not reset to attempts: complete the initial picture first. |
| 02Check and separate hypotheses |
| External causes, configuration, circuit and separate process. | If the data does not match, return to the correct schema and revision before changing parameters. |
| 03Interpret and demonstrate |
| Cause supported by repeatable data and authorized evidence. | If the cause is not proven, stop changes and involve manufacturer, OEM or machine manager. |
Reading and observation
Recognize and collect
- Transcribe nSt and indicate the local/remote mode and the control mode of the machine.
- Collect the input scheme and the state shown by the diagnostic.
Event context and complete initial data.
If the result does not matchIf a data is missing, do not reset to attempts: complete the initial picture first.
Qualified technician
Check and separate hypotheses
- Compare the status of inputs with assignments and control to two or three expected wires.
- Distinguish a stop command from a security function: do not change or bridge the consents.
External causes, configuration, circuit and separate process.
If the result does not matchIf the data does not match, return to the correct schema and revision before changing parameters.
Specialist deepening
Interpret and demonstrate
- Evaluate the PLC sequence, arbitrage of channels and behavior in return.
- Use the FAQ only for the described configuration and manual for all other combinations.
Cause supported by repeatable data and authorized evidence.
If the result does not matchIf the cause is not proven, stop changes and involve manufacturer, OEM or machine manager.
What to avoid
- Use repeated resets as a diagnostic test.
- Transfer codes, thresholds or parameters from one Drives family to another.
- Change a protection before connecting symptoms, measurement and phase of the cycle.
- Do not bridge inputs or STO to delete nSt. Identify the request for arrest and its origin.
When the problem is really solved
The test must demonstrate the authorized start and correct stop from the required commands.
- The cause is supported by data and not only by the momentary absence of the alarm.
- The cycle that generated the problem has been repeated in authorized conditions.
- Final configuration, measurements and outcome are consistent with applicable machine, drive and documentation.
Applicable documents
Always check size, firmware, options and revision. These sources do not extend the case to other families.
- Primary source of the caseOpen the official source la
- Schneider Electric · Programming and DiagnosticManual · EN · EAV64318 · Official PDF
- Schneider Electric · Safety functionsManual · EN · EAV64334 · Official PDF