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In high-voltage power systems, ensuring the safety of operation and maintenance is the top priority. In the key components of guarding personnel and equipment safety, isolation switches (also known as isolators or disconnecting switches) play an irreplaceable role. Unlike circuit breakers that focus on fault isolation, the core mission of circuit breakers is to provide a reliable “visible disconnection point” for the inspection and maintenance of power systems.
This guide will comprehensively interpret the изолирующий выключатель, covering its definition, working principle, types, and application scenarios, while highlighting the advantages of Чуаньли solutions to help you gain a deeper understanding of this essential component of the power system.
Isolation switch is a high-voltage electrical component used to isolate a certain part of the power system from the main power grid. Its core feature is that when the circuit breaker is in the open state, the air insulation gap between the broken contacts can be clearly visible, clearly indicating that the isolated part has been de-energized.
Special attention should be paid to the fact that the изолирующий выключатель does not have the ability to interrupt the load current or fault current (such as short-circuit current), and must be operated after the circuit is unloaded or the current has been cut off by the circuit breaker. The GGW4-12 outdoor circuit breaker series strictly follows this operating principle. The structural design is centered on safe isolation, rather than current interruption.
The working principle of the изолирующий выключатель is based on the mechanical movement of the conductive contact to realize the connection or isolation. Taking the outdoor high-voltage изолирующий выключатель as an example, it can be divided into three key stages:
Preparation before operation: Before operating the изолирующий выключатель, it is necessary to confirm that the associated circuit breaker has been disconnected and ensure that the circuit is in a non-load state. Чуаньли products can be configured with auxiliary interlocking devices. If the circuit breaker is in the closed state, it will lock the изолирующий выключатель operation to prevent misoperation.
Contactor movement: Through manual operation (such as a handle) or electric operation of the mechanism, the moving contact of the circuit breaker is driven to separate or engage with the static contact. When the circuit breaker is opened, the movable contact is far away from the stationary contact, and an air gap gradually forms; When the circuit breaker is closed, the two contacts are in close contact, achieving a reliable mechanical and electrical connection, and ensuring low resistance conduction.
Isolation and insulation: After the circuit breaker is completely closed, the visible gap between the contacts provides reliable insulation, preventing electrical energy from entering the isolated equipment. The outdoor изолирующий выключатель из Чуаньли has optimized the contact gap and insulation structure, so that even in harsh outdoor environments, air insulation can meet the requirements of high-voltage scenes.
As the core safety component in the power system, the circuit breaker undertakes many key functions, which are fully reflected in the application of Чуаньли products:
Secure isolation: The most basic function. When electrical equipment such as transformers, capacitors, and cables need to be inspected, the изолирующий выключатель is opened to isolate the equipment from the live power grid, creating a safe working area for the maintenance personnel. The visible disconnection gap of Чуаньли products provides an intuitive safety guarantee and eliminates the risk of accidental electrification.
Circuit conversion: In some distribution scenarios, it is used to switch between different power supply branches or to switch on/off backup equipment. For example, in the substation, the изолирующий выключатель can realize the conversion of the main and backup power supply lines, ensuring the continuity of power supply.
Carrying empty load current: It can temporarily carry small empty load current, such as transformer empty load current and cable charging current, but cannot cut off these currents. The current-carrying capacity design of the hydraulic high-voltage изолирующий выключатель is reasonable and meets the requirements of such scenarios.
Grounding protection: Many circuit breakers are equipped with grounding blades. After isolating the equipment and closing the grounding blade, the residual charge of the equipment can be transferred to the earth, further ensuring the safety of maintenance. The GGW4 series from Чуаньли can be equipped with grounding devices on demand to enhance safety performance.
According to the installation environment, structure form, voltage level, etc., the изолирующий выключатель can be divided into many types to adapt to different application scenarios. Чуаньли provides a full range of products covering mainstream types:
Outdoor and indoor circuit breakers: Outdoor circuit breakers are designed with weather-resistant structures and have the characteristics of waterproof, dustproof, anti-corrosion, and anti-icing, and are suitable for outdoor substations, distribution lines, and other open-air environments; The indoor circuit breaker has a compact structure and is suitable for indoor switch cabinets and enclosed substations, focusing on saving space and insulation coordination.
Single-phase изолирующий выключатель and three-phase isolation switch: Single-phase products are mainly used in single-phase power systems or specific equipment branches; The three-phase isolation switch is widely used in three-phase AC power system, and the three sets of contacts act synchronously to ensure that the three phases are simultaneously connected or isolated. The high-pressure products of Chuanli are mostly three-phase integrated design, which is efficient for the system.
Simple изолирующий выключатель and knife switch isolation switch: Simple contact structure, suitable for low voltage or small current scenarios; The knife-type (common in high-voltage applications) uses a knife-type movable contact, which has better current carrying capacity and isolation performance. Чуаньли high-voltage isolation switches are mainly of knife-gate structure, meeting the requirements of high-voltage operation.
Manual изолирующий выключатель and electric isolation switch: Manual type is operated by a handle or lever, suitable for low-frequency operation scenarios; The electric type adopts an electric motor driving mechanism, which can realize remote control and automatic operation, and is suitable for large substations and unmanned power stations. Chuanli products support manual and electric operation modes, which can be flexibly selected.
| Comparison Dimension | Isolation Switch (Isolator) | Автоматический выключатель |
| Core Function | Provide safe isolation and visible disconnection | Interrupt load current and fault current, protect the circuit |
| Current Interruption Capacity | Cannot interrupt load current or fault current | Can reliably interrupt various currents, including short-circuit current |
| Structural Feature | Simple structure, no complex arc-extinguishing system | Complex structure, equipped with special arc-extinguishing chamber |
| Operation Scenario | Operated under no-load or after circuit breaker opens | Can be operated under load or fault conditions |
| Safety Significance | Protect maintenance personnel (passive safety) | Protect power equipment and grid (active protection) |
In practical applications, the two complement each other. For example, in the substation, the fault current is first cut off by the circuit breaker, and then the изолирующий выключатель is opened to isolate the fault equipment for inspection – this combination ensures the safe and reliable operation of the power system.
High-voltage isolation switches are widely used in all aspects of high-voltage power systems due to their safety isolation function. Chuanli products have accumulated rich application experience in the following fields:
Power substations: This is the most concentrated application scenario. Transformers, busbars, and capacitor banks in the substation are equipped with isolation switches to achieve equipment isolation and circuit switching. The GGW4-40,5 series is commonly used in 35kV substations.
Industrial enterprises: Large factories (such as steel mills and chemical plants) and mining areas have independent high-voltage distribution systems. High-voltage isolation switches are used to isolate high-voltage motors, transformers and other equipment during maintenance, ensuring production safety.
New energy power station: In photovoltaic and wind power stations, the изолирующий выключатель is installed at the generator bus bar and the input of the box-type substation. When repairing, it isolates the power generation system to avoid impacting the power grid.
Urban power distribution network: In urban high-voltage power distribution lines, outdoor circuit breakers are used for line segmentation, isolation of fault lines, convenient maintenance, and reducing the scope of power outages.
Special power scenarios: In the power systems of railways, airports, large data centers, etc., the isolation switch provides reliable isolation protection for key power equipment, ensuring the continuous stable operation of special loads.
Choosing an appropriate isolating switch is crucial for ensuring the safe and efficient operation of the power system. Combining with the professional experience of Чуаньли, the following core selection criteria are proposed:
Confirm the voltage and current level: According to the rated voltage (e.g., 12 kV, 40.5 kV) and rated current of the system, select the corresponding specification of the circuit breaker. For example, 10 kV distribution lines should be selected with 12 kV-class products such as Чуаньли GGW4-12 to ensure that the current carrying capacity of the switch is greater than the maximum operating current of the circuit.
Specify the installation environment: Outdoor applications must choose outdoor isolation switches with weather resistance, focusing on indicators such as waterproof grade, anti-corrosion performance, and temperature adaptability; Indoor applications can choose compact indoor products as a priority to save space.
Determine the operation mode: For frequent operations or unattended operations, use electric isolation switches to improve efficiency; Manual operation is more economical in scenarios with low operation frequency and convenient manual operation.
Considering safety configuration: In high-risk inspection scenarios, choose products with grounding blades and interlocking devices to prevent misoperation. Чуаньли products can be customized with multiple interlocking functions according to demand (such as mechanical interlocking with circuit breakers).
Verify the manufacturer’s qualifications: Choose manufacturers with complete production qualifications, mature technology, and perfect after-sales service, such as Чуаньли, to ensure that the product passes type testing and meets national standards (such as GB / T 1985), and avoid safety hazards caused by low-quality products.
In the highly competitive high-voltage electrical equipment market, Чуаньли High-Voltage Isolate Switch, especially the GGW4 series outdoor products, has won the trust of a large number of users with its outstanding advantages:
Excellent environmental adaptability: The outdoor изолирующий выключатель adopts a fully sealed insulation structure and anti-corrosion coating, which can operate stably in harsh environments such as -40 ℃ super low temperature, 60 ℃ high temperature, heavy rain, heavy snow, strong sand and wind, with a protection level of IP65 or above, suitable for the climate characteristics of various regions in China.
High safety and reliability: The contact system uses high conductivity copper alloy materials, with small contact resistance and strong carrying capacity; The operating mechanism is equipped with self-locking function to prevent accidental opening and closing; It can be seen that the disconnection gap strictly complies with the standard requirements and provides reliable safety protection.
Complete product series: Covering 12 kV, 17.5 kV, 40.5 kV, and 126 kV voltage levels, providing single-phase, three-phase, manual, and electric products, the GGW4 series can be customized according to user needs to meet the matching requirements of different power systems.
Convenient installation and maintenance: Modular design, standardized connection parts, simple installation process, which can shorten the on-site construction period; The product has a long service life (up to 30 years), a low failure rate, and only requires regular inspection of contacts and operating mechanisms for daily maintenance, reducing the cost of later operation and maintenance.
Professional technical support: Provide one-stop service from pre-sales project design, in-sales installation guidance to after-sales maintenance. The professional technical team can quickly respond to user needs, solve technical problems in a timely manner, and ensure the smooth operation of the equipment.
As a key safety component in high-voltage power systems, the изолирующий выключатель/isolator/disconnecting switch plays an important role in ensuring the safety of maintenance and realizing circuit isolation. Its “visible break point” characteristic is irreplaceable by other electrical components, and is a necessary guarantee for the safe and stable operation of the power system.
Whether it is urban power grid renovation, industrial enterprise distribution, or new energy construction, Чуаньли can provide suitable изолирующий выключатель solutions. Choosing Чуаньли products is to choose a solid security barrier for the power system.
Q1: Can an isolating switch break load current?
A1: No. It can only operate in the absence of load, and the load current must first be cut off by the circuit breaker.
Q2: What is the difference between an isolator and a circuit breaker?
A2: Isolating switch: Focuses on isolation, has visible gaps, and does not have the ability to interrupt current;
Circuit breaker: can interrupt load/fault current, realize active protection.
Q3: What does “visible disconnection” mean?
A3: After the circuit breaker is opened, a clear air gap is formed between the contacts, which can intuitively confirm that the circuit has been de-energized, ensuring the safety of maintenance.
Q4: Are outdoor isolating switches weather-resistant?
A4: Да. Чуаньли products have a protection level of IP65+, which can withstand extreme temperatures, rain, and wind and sand.
Q5: How do I select the correct voltage rating?
A5: If you choose a specification higher than the system rated voltage (e.g., 12kV for a 10kV system), please consult Чуаньли for customization.
