InverterS300Verification pending — cross-check with the official manual
S300 ULt — Under Load
Trip — immediate stop
CAUSE
Why does it occur?
- Under load protection, motor load within set under load level
- Operates when PRT-27 is set to non-zero
REMEDY · Step by step
How to fix it?
- Check motor-load connection
- Increase underload level (PRT-29, PRT-30)
Do not reset repeatedly before identifying the cause. Repeated resets while ignoring a trip/alarm can cause secondary damage (IGBT failure, motor winding damage, etc.).
SOURCE
Related manual page
CALLBACK
Request an expert callback
A 12-year automation/SI engineer responds directly. Reply within 1–3 business days.