Cause : Input Phase Loss (Main Circuit Voltage Fault) comes when the main circuit DC voltage oscil- lates unusually (not when regener- ating). This fault is detected if a load is greater than approximately 80% of the maximum motor capacity. This fault is detected when L8-05 is set to 1.

1. An open-phase occurred in the input power supply. 
2. A momentary power loss occurred.
3. The wiring terminals for the input power supply are loose.
4. The voltage fluctuations in the input power supply are too large.
5. The voltage balance between phases is bad.
6. Reset the fault after correcting its cause.