Er150: Encoder signal loss / synchronization error (e.g., pulse signal interruption, A/B phase deviation).
Er151: Excessive encoder signal noise / abnormal fluctuation (e.g., misjudgment caused by interference).
Both alarms are directly related to encoder signal stability. When these alarms are triggered on drives that are not servo-enabled, this typically indicates systemic interference (e.g., electromagnetic coupling between multiple devices).
Recommendations: Prioritize hardware and wiring inspection (the most likely root cause):
- Ensure all components with grounding terminals inside the electrical cabinet are properly bonded to the cabinet ground busbar, and verify that the entire cabinet is reliably grounded.
- Check whether encoder cables are routed adjacent to or share conduits with noise-generating equipment such as VFDs, welders, or high-power contactors. Reroute encoder cables to maintain adequate separation from noise sources, then retest.