I. Common Fault Types and Diagnostic MethodsElectrical Faults Circuit Breaker Failure to Operate or Maloperation: Check the energy storage mechanism, closing/tripping coils, auxiliary switches, and secondary circuits. High-Voltage Fuse Blown: Measure voltage across the fuse terminals; inspect busbar joints, cable terminations, and protection relay settings. Busbar Discharge or Insulator Damage: Listen for discharge sounds, check temperature at busbar connections, and visually inspect insulators

Types and Common Fault Analysis of High-Voltage SwitchgearHigh-voltage switchgear is a critical electrical device in power systems. Deterioration in switchgear operation is one of the main causes of power system failures. What are the common faults in high-voltage switchgear?(1) Outdoor and Indoor TypesBased on installation environment, high-voltage switchgear can be classified as outdoor or indoor types. Equipment rated at 10 kV and below is mostly installed indoors. According to primary circui

Oil-Immersed Transformers: Overview, Features, and ApplicationsAn oil-immersed transformer is a widely used type of power transformer that employs a liquid—typically insulating oil—as both an insulating and cooling medium.Key Features of Oil-Immersed Transformers: Insulating Oil: Insulating oil serves as the primary dielectric medium, electrically isolating the windings from the core and ground. With its high dielectric strength, it effectively prevents electrical breakdown between windings or b

The absorption ratio is defined as follows: When operating a megohmmeter (insulation resistance tester), rotate the handle at a speed of 120 revolutions per minute. Record the insulation resistance reading at 15 seconds (R15) and then at 60 seconds (R60). The absorption ratio is calculated using the formula:Absorption Ratio = R60 / R15, which should be greater than or equal to 1.3.Measuring the absorption ratio helps determine whether the insulation of electrical equipment is damp. When insulati

I. Operational Analysis1.1 Operating ScopeHigh-voltage disconnect switches are classified into outdoor and indoor types based on installation location, and into three-pole or single-pole configurations according to the number of poles. During operation, attention must be closely paid to the switch’s operating current and voltage.If the operating voltage exceeds the rated value, discharge may occur within the porcelain insulator. The degree of heating is closely related to the operating current a

During the operation of high-voltage disconnect switches, arcs may form between the contacts when they separate while current is still flowing. The high temperature of the arc not only damages the switch contacts but can also ignite surrounding flammable materials, leading to safety accidents.Arc formation is influenced by various factors, including the type of current (DC or AC), the inductive and capacitive characteristics of the circuit, and the properties of the contact materials. In DC syst

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,