Vector control is a model-based technology, and the identification run is where the model meets your actual motor — cable and all. Skipping it is the most common commissioning shortcut we get called to undo.
What the drive measures
Standstill identification injects test signals without rotation: stator resistance, leakage inductances, valve interlock times. It runs with the load coupled and is the minimum for any vector operation. Rotating identification spins the uncoupled motor to find magnetizing characteristics and rated slip precisely — this is where low-speed torque quality and field-weakening accuracy come from.
Symptoms of missing or stale ID data: hunting at low frequency, poor starting torque, torque limit trips at moderate loads, temperature model complaints, and current that never quite matches the load story.
When to (re)identify
- At commissioning, obviously — after entering nameplate data exactly (a wrong rated frequency poisons everything downstream).
- After replacing the motor, even “identical” spares — manufacturing spread is real.
- After significant cable length changes — the drive measured the cable too.
- When a swapped drive inherits parameters from a backup made on different hardware: the backup carries the old measurements.
If the process cannot be uncoupled, run standstill ID and accept the compromise knowingly — and note it in the commissioning report.
FAQ
Is ID safe with the load coupled? Standstill ID, yes. Rotating ID must be able to spin freely — on a hoist or saw, that means uncoupled, or skipped with documented consequences.
Why do two identical motors need separate ID? Because they are only catalog-identical. The few percent of parameter spread is exactly what the model is sensitive to at the performance margins.
Zone Otomasyon’s commissioning checklists make skipped IDs impossible to hide. Commissioning done properly.