低压成套柜母排连接热失效诊断与处置方法

Diagnosis and Disposal Method for Thermal Failure of Busbar Connections in Low-Voltage SwitchgearYao Xia₁^,Zhu Enze_²

摘要: 针对低压成套柜母排螺栓连接处局部过热且单一红外测温难以判别故障性质的问题,以某0.4 kV、1600 A成套柜的5个连接点为对象,建立运行负荷与环境温度同步记录、红外热像筛查、接触电阻和紧固扭矩核查、停电解体、界面修复及带载复测组成的诊断处置链。结果表明,P2点处置前负荷归一化温升为64.7 K、接触电阻为108.6 μΩ,界面存在深色氧化和偏侧压痕；修复并分级交叉紧固后,两项指标分别降至24.9 K和30.8 μΩ。5个点的归一化温升降低49.2%～61.5%,接触电阻降低37.9%～71.6%,扭矩偏差均恢复至验收区间。该方法可将温度异常与连接界面缺陷对应,并通过复测和周期跟踪抑制误判及温升反弹,适用于螺栓搭接母排的现场处置。

Abstract: Five bolted busbar connections in a 0.4 kV, 1600 A switchgear were diagnosed using synchronized load and ambient-temperature records, infrared screening, contact-resistance and torque checks, outage inspection, interface repair, and on-load retesting. At P2, normalized temperature rise and contact resistance fell from 64.7 K and 108.6 μΩ to 24.9 K and 30.8 μΩ. Across all points, the two indicators decreased by 49.2%–61.5% and 37.9%–71.6%, and torque deviations returned to the acceptance range. The method links thermal evidence to interface defects and supports field disposal of bolted busbar joints.