The reference changes but the speed does not follow
Separate process request, received signal, active reference and output of the drive. A percentage value on the controller does not show what the Drives receives.
The case in 60 seconds
Separate process request, received signal, active reference and output of the drive. A percentage value on the controller does not show what the Drives receives.
Record controller request, displayed value on the drive and operating mode.
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
- Record controller request, displayed value on the drive and operating mode.
- Note the signal type provided by the scheme: do not deduce it from the terminal.
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 active channel, input type, scale and limits with approved configuration.
- The measurements on the circuit require appropriate tools and procedures; preserves values and units at the two extremes of the path.
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 PLC references, limitations, PIDs and logic prior to changing the scale.
- A signal simulation should be planned in the test of the machine: do not replace operational sensors at attempts.
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 apply tensions or currents to an input without identifying the type and limits. Do not force the reference during uncontrolled exercise.
When the problem is really solved
Request, entry and reference are consistent in the authorized field; also records any active limits.
- 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 · Programming and DiagnosticManual · EN · NVE41295 · Official PDF
- Schneider Electric · Programming and DiagnosticManual · EN · S1A53838 · Official PDF