Free Expert Guides on Power Systems, Circuit Design & Electrical Troubleshooting

Installation Requirements for Isolating SwitchesBefore installing an isolating switch, a thorough visual inspection must be carried out. The main items to check include:(1) Verify that the model and specifications of the isolating switch match the design requirements.(2) Inspect all components for damage and check whether the blade or contacts are deformed. If deformation is found, it should be corrected.(3) Examine the contact condition between the movable blade and the contacts. Any copper oxi

Transformer Neutral Grounding Disconnector: Function, Principle, Structure, Operation, and MaintenanceA transformer neutral grounding disconnector is an electrical device used to isolate the neutral point of a power transformer. Its primary purpose is to protect both the transformer and the overall power system, ensuring safe and stable operation.I. Functions of the Transformer Neutral Grounding DisconnectorTransformer ProtectionOne of the key roles of the neutral grounding disconnector is to sa

The following are methods for handling accidents and abnormalities related to isolating switches:(1) If an isolating switch fails to operate (refuses to open or close), take the following steps:① For mechanically operated isolating switches that fail to open or close, check whether the circuit breaker is open, whether the mechanical interlock of the isolating switch has been released, whether the transmission mechanism is jammed, and whether the contacts are rusted or welded. Gently wiggle the o

When performing switching operations, operating personnel must carefully verify that the circuit breaker is indeed in the open position. For three-pole interlocked isolating switches, all three phases must move simultaneously, with a maximum allowable vertical discrepancy of no more than 3 mm, before any opening or closing operation of the isolating switch is permitted.1. Key Points for Closing an Isolating SwitchFor manual operation, operating personnel should first remove the interlock pin bef

In substations, the number of isolating switches is generally 2 to 4 times that of circuit breakers. Due to their large quantity, the workload for installation and commissioning is considerable. For voltage levels below 110 kV, the GW4-type isolating switch serves as the dominant equipment. If the installation workmanship and mechanical dimensional adjustments of the isolating switch do not meet requirements, issues such as incomplete opening/closing, overheated contacts, or even porcelain insul

Application of Isolating Switches in Generator Neutral Grounding Resistor CabinetsIsolating switches are commonly installed in NS-FZ generator neutral grounding resistor cabinets. They provide a clearly visible disconnection point, ensuring the safety of maintenance and testing personnel. However, as high-voltage devices without arc-quenching capability, isolating switches must only be operated when the circuit is de-energized—i.e., under no-load conditions.The primary function of an isolating s

The selection principles and precautions for fuse-switch disconnectors are crucial to ensuring the safe and stable operation of power systems.Selection Principles for Fuse-Switch Disconnectors Rated Voltage:The rated voltage of the fuse-switch disconnector shall be equal to or greater than the rated voltage of the electrical system to ensure the equipment operates normally without damage. Rated Current:The selection of rated current should be based on the load conditions of the electrical system

HVDC disconnector switches:HVDC disconnecting switches (DS) are used to disconnect various circuits in HVDC transmission networks. For example, the HVDC DS is applied to switching duties such as line or cable-charging current switching, no-load line, or cable transfer switching, in addition to disconnecting equipment including a converter bank (thyristor valve), a filter bank, and a grounding line. HVDC DS is also applied to DC switchgear to terminate the residual or leakage current through an in