The main causes of overheating in high-voltage VTZ-12 vacuum circuit breakers can be summarized into the following four categories, involving factors such as contact contact, equipment installation, load, and material properties:
Poor contact at the contacts
Oxidation, dirt, or loosening of the contact surfaces lead to increased contact resistance (<75μΩ), creating a vicious cycle. Arrow discharge damages the electroplated layer on the contact surface, exacerbating material corrosion and increasing resistance.
Equipment Installation and Workmanship Issues
Construction quality defects, such as misalignment of the trolley-type plug, leading to poor contact. Loose connection between the conductive rod and the junction box, or oxidation of transition parts and fasteners.
Abnormal load
The operating load is too high or changes frequently, exceeding the equipment's design range, causing the temperature to rise.
Material and Structural Characteristics
The contacts employ a multi-layered trapezoidal contact finger structure in a plum blossom shape. After long-term operation, the performance of the contact material deteriorates.
Arc erosion in a vacuum environment accelerates phase transformation and damage to contact materials.
Equipment aging and deformation are among the many factors that can cause contact heating. In addition to the reasons mentioned above, equipment aging and deformation can also increase contact resistance, leading to contact heating. Practice has shown that after prolonged use, the performance, parameters, and mechanical strength of the contacts will decline. Under such circumstances, the aging of the contact self-closing spring will occur or directly reduce its elasticity.During operation, the above reasons can weaken the contact pressure of the contacts, resulting in poor contact and directly increasing the contact resistance. If poor contact is not addressed in time, it will cause the connection of the joint to deteriorate, leading to severe overheating of the contacts. In more serious cases, it can even cause the contacts to burn out.
Recommendations
Regularly check the cleanliness of the contacts, optimize the installation process, control the load operating range, and strengthen equipment maintenance to reduce contact resistance.
Shaanxi West Power Tongzhong Electrical Co., Ltd.
Our address
Nanpo Village, Chencang Avenue Jintai District Baoji City, Shaanxi Province, China.
Phone Number
+86 18091767067(WhatsApp/Wechat/Telegram)
