12kV 24kV 35kV 72.5kV Composite Post Insulator

I. Fuse Structure and Root Cause AnalysisSlow Fuse Blowing:From the design principle of fuses, when a large fault current passes through the fuse element, due to the metal effect (certain refractory metals become fusible under specific alloy conditions), the fuse first melts at the soldered tin ball. The arc then rapidly vaporizes the entire fuse element. The resulting arc is quickly extinguished by quartz sand.However, due to harsh operating environments, the fuse element may age under the comb

Common Causes of Fuse BlowingCommon reasons for fuse blowing include voltage fluctuations, short circuits, lightning strikes during storms, and current overloads. These conditions can easily cause the fuse element to melt.A fuse is an electrical device that interrupts the circuit by melting its fusible element due to heat generated when current exceeds a specified value. It operates on the principle that, after an overcurrent persists for a certain period, the heat produced by the current melts

1. Fuse MaintenanceFuses in service should be regularly inspected. The inspection includes the following items: Load current should be compatible with the rated current of the fuse element. For fuses equipped with a fuse blown indicator, check whether the indicator has actuated. Check the conductors, connection points, and the fuse itself for overheating; ensure connections are tight and making good contact. Inspect the fuse exterior for cracks, contamination, or signs of arcing/discharge. Liste

I. Routine Maintenance and Inspection(1) Visual Inspection of Switchgear Enclosure No deformation or physical damage to the enclosure. Protective paint coating shows no severe rust, peeling, or flaking. Cabinet is securely installed, clean on the surface, and free of foreign objects. Nameplates and identification labels are neatly affixed and not falling off.(2) Check of Switchgear Operating Parameters Instruments and meters indicate normal values (comparable to typical operating data, with no s

This article categorizes faults into two main types: SF₆ gas circuit faults and circuit breaker failure-to-operate faults. Each is described below:1.SF₆ Gas Circuit Faults1.1 Fault Type: Low gas pressure, but density relay does not trigger alarm or lockout signalCause: Faulty density gauge (i.e., contact not closing)Inspection & Handling: Calibrate actual pressure using a standard gauge. If confirmed, replace the density gauge.1.2 Density Relay Triggers Alarm or Lockout Signal (but pressure

GIS (Gas-Insulated Metal-Enclosed Switchgear) contains numerous bolted and screwed connections, and the tightening torque varies depending on bolt material, size, and application. The recommended tightening torque values are listed below for reference:Table 1 Tightening Torque Values for Bolts of Different Materials and Sizes (N·m / kgf·cm) Thread Diameter (mm) Q235 (A3) Cast Insulator 45 Steel Chrome-Molybdenum Steel Stainless Steel M6 5.88/60 3.92/40 12.3/125 19.6/

I. Background and Challenges​Shore power systems have become core technical equipment for ports to reduce carbon emissions and noise pollution. However, these systems face two major challenges in the harsh operational environment of ports:​Severe Environmental Corrosion: High humidity and salt spray in port areas cause serious corrosion to metal components and enclosures of electrical equipment, significantly impacting electrical lifespan and operational reliability.​High Switching Requirements:

Issue Overview​The 10kV air compressor starting system of a company utilizes the ABB vacuum contactor KC2 as the control component for the operating circuit. The dedicated wide-voltage power supply module paired with this contactor presents the following issues:​Frequent failures: The power supply module fails to properly transition the voltage from 300V to 12V, resulting in fuse blowouts.​Poor heat dissipation: Enclosed installation of the module leads to insufficient heat dissipation, acceler

1.Project BackgroundA coal conveying system comprises 15 belt conveyors driven by medium-voltage motors. The system operates under complex conditions, with motors often subjected to heavy loads and frequent starts. To address these challenges and achieve effective control and reliable protection during motor startup, the project comprehensively adopts Vacuum Contactor-Fuse (VCF) combination devices for the 6kV medium-voltage motor power distribution. This solution details the technical features,