On July 15, in the sweltering heat of midsummer at Guantan village, Longyou county, Quzhou city, State Grid Quzhou Power Supply Company's field crews used a newly-launched low-voltage latent-fault intelligent diagnosis system to pinpoint a household at risk. After an on-site check, they replaced a burnt-out service-drop knife switch caused by poor contact and installed a dedicated copper-to-aluminum transition lug, promptly cleared the hidden danger within minutes.

As temperatures climb, so does electrical load, making loose connections, overloads and hot spots more likely to trigger outages. Traditional foot patrols, limited by efficiency and coverage, often miss these subtle, concealed faults—exactly the kind that become critical during summer peaks.

To solve this problem and keep the distribution network resilient under high load and high temperature, State Grid Quzhou Power Supply has activated the low-voltage latent-fault intelligent diagnosis system. Powered by big-data analytics and AI, the system continuously monitors and analyses massive streams of current and voltage data from distribution transformer areas. Its algorithms flag early-warning patterns—such as loose clamps, clamp overheating or overloads—then automatically generate a precise customer list for field inspection. In effect, it gives maintenance crews a "technological eye" and a guide plan, shifting the safety checkpoint from reactive repair to proactive elimination.