Preventive maintenance is the best cure:
Random 366 alarm on Y-axis during heavy cuts, but motor was cool to the touch. Cause: Shielding failure on the power cable caused intermittent ground fault. The servo amp saw current spikes, calculated heat, and alarmed. Solution: Megger-tested the motor cable, found breakdown. Replaced cable. fanuc 366 alarm
Verify that the cable shielding is properly grounded to prevent signal "misses" due to electrical noise. Check Other Alarms: This alarm sometimes follows others, such as SV0364 (Soft Phase Alarm) . Resolving related alarms may clear the 366 error. Swap Components for Testing: Preventive maintenance is the best cure: Random 366
It is vital to distinguish Alarm 366 from Alarm 46 (Hard Thermal). The "hard" thermal relies on a physical bimetal switch inside the motor. The uses the servo amplifier’s CPU to calculate the motor's heating effect. It integrates the absolute value of the motor current (torque) over time. When this calculated value exceeds a pre-set threshold (parameter 6071 or equivalent), the 366 alarm triggers. Solution: Megger-tested the motor cable, found breakdown