Why Should The No-load Opening And Closing Operation Of The Fuse Be Verified At Least Three Times After Installation?

For devices like the drop out fuse, which perform fault-breaking functions, their mechanical structure, electrical contacts, and installation conditions all affect their actual opening and closing performance. Repeated opening and closing actions allow observation of whether the operating contacts are smooth, whether the actuating mechanism experiences abnormal resistance, and whether the position feedback is consistent.

Multiple opening and closing processes during no-load testing help identify loosening, misalignment, or poor contact that may occur during installation. These issues can amplify into more serious faults or affect system stability under load. Even in the rated performance verification of circuit breakers and high-voltage switchgear, attention is paid to the reliability characteristics of the equipment performing breaking actions under no-load conditions.