2026-10-12 For SF6-insulated Ring Main Units (RMU) or GIS, the leakage rate requirement depends on whether the gas compartment is classified as a closed pressure system or a sealed pressure system under IEC standards. 1. IEC 62271-1 (General HV Switchgear Standard) IEC 62271-1 defines: Gas system type Maximum SF6 leakage rate Closed pressure system ≤ 0.5% per year […]

2026-10-12 Current transformers are widely used in power systems; their function is to induce a small current—proportional to the current flowing through a high-current cable—for use in metering and relay protection. What is the function of a current transformer? To ensure the safe and economical operation of a power system, it is essential to monitor

2026-06-10 I.Medium-voltage circuit breakers mainly consist of the circuit breaker body and the operating mechanism. With continuous technological updates to circuit breakers, the possibility of failure in the circuit breaker body is decreasing, and circuit breaker failures are concentrated in the operating mechanism. According to statistics on medium-voltage circuit breaker operation failures, among various circuit

2026-06-10 The “opening and closing coil” of a high-voltage circuit breaker is an important component of the circuit breaker’s electric operating mechanism. It is a hollow cylindrical coil wound with copper wire, possessing excellent conductivity. When current passes through the coil, it generates a magnetic field, which, through electromagnetic force, drives the positioning pins of

2026-01-05 Functional Role of the Earthing Switch In medium-voltage ring main units (RMUs), the earthing switch (ES) is often regarded as a device intended solely for maintenance grounding. However, under several credible operating and fault conditions, the earthing switch may be required to make onto a live circuit and withstand the resulting short-circuit current. For

2025-04-15 According to the newly revised “Preventive Test Procedures for Power Equipment”, the moisture content of SF6 switches for newly commissioned and overhauled arc extinguishing compartments shall not exceed 150ppm, and shall not exceed 300ppm during operation. As for the harm of micro-water, the reason is obvious and will not be explained here. We mainly

2024-12-12 When the high-voltage circuit is disconnected, the voltage will break down the air to produce high-temperature and high-conductivity free gases, which appear as instantaneous high-temperature sparks, which are arcs. The damage of arc is very high: the arc will generate high temperature, which will ablate the surface of the contact and burn out the

2024-12-12 Xiamen, China, is the destination of Ma Teng, global president of ABB Group’s electrical business, as his “first business trip” in the new year. On January 9, 2024, executives of this Fortune 500 company made a special trip to Xiamen from the Netherlands and announced that “in the next three years, they will further

2014-12-12 The multinational company Schneider Electric has increased its presence in Xiamen Torch High-tech Zone. On April 26, 2024, the Xiamen Torch Electric Power Industrial Park (Phase I) project officially started construction. After the project is completed, it will serve as the Schneider Electric (Xiamen) Industrial Park, creating its largest medium-voltage production base in the

2024-12-12 On November 14, 2024, Hitachi Energy successfully held the 25th anniversary celebration of the high-voltage switch manufacturing base in Xiamen. A total of about 120 industry insiders from home and abroad were invited to attend the on-site event to witness the outstanding achievements of Xiamen Hitachi Energy High Voltage Switch Co., Ltd. over the