Different from conventional switchgear that relies heavily on installation environments, Usune 11kv Sf6 Gis Gas Insulated Switchgear isolates the main electrical components inside a sealed gas compartment. The integrated mechanical interlocking system helps prevent incorrect operations, improving both operator safety and equipment reliability.
The switchgear is widely used in transformer substations, industrial power distribution systems, commercial buildings, infrastructure projects and other 11kV medium-voltage applications where safety, reliability and easy operation are essential.
The main circuit components are enclosed inside a sealed SF6 gas tank, reducing direct exposure to external environmental conditions. This design helps protect electrical components from dust, moisture, pollution and condensation, improving long-term operating stability.
The enclosed structure also reduces the space requirement compared with traditional air-insulated switchgear, making Usune 11kv Sf6 Gis Gas Insulated Switchgear suitable for compact substations and space-limited electrical rooms.
Usune 11kV SF6 GIS is designed with multiple mechanical safety protections to prevent incorrect operation. All switches must be operated using the dedicated operating handle, ensuring controlled switching procedures.
The load break switch or vacuum circuit breaker and the corresponding grounding switch are equipped with internal mechanical interlocking. Additional padlock interlocking can also be applied when required, providing higher security during maintenance and operation.
The lower door can only be opened when the grounding switch is closed and the load break switch is in the open position, preventing access to energized parts.
The grounding switch cannot be operated when the lower door is open, helping prevent unsafe maintenance conditions.
The load break switch cannot be closed when the grounding switch is closed, and the grounding switch cannot be operated when the load break switch is closed.
For power supply operation, the cable compartment door must be closed first. The three-position switch is then operated from grounding position to isolation position and finally to closing position.
For power isolation, the three-position switch is operated from closing position to isolation position and then to grounding position, allowing safe access to the cable compartment.
| No. | Items | Unit | Load break switch unit | combination unit | Circuit breaker unit |
| 1 | Rated voltage | kV | 12/24 | 12/24 | 12/24 |
| 2 | Rated frequency | Hz | 50 | 50 | 50 |
| 3 | Rated current | A | 630 | 125 (depends on fuse current) | 630 |
| 4 | Rated insulation level‑1min Frequency withstand voltage‑Inter phase, ground | kV | 42/65 | 42/65 | 42/65 |
| Rated insulation level‑1min Frequency withstand voltage‑isolating distance | kV | 48/79 | 48/79 | 48/79 | |
| Rated insulation level‑1min Frequency withstand voltage‑Controlling and auxiliary circuit | kV | 2/2 | 2/2 | 2/2 | |
| Rated insulation level‑Lighting impulse withstand voltage‑Inter phase, ground | kV | 75/125 | 75/125 | 75/125 | |
| Rated insulation level‑Lighting impulse withstand voltage‑isolating distance | kV | 85/145 | 85/145 | 85/145 | |
| 5 | Rated short circuit withstand current | kA/s | 25/4 | —— | 25/4 |
| 6 | Rated peak withstand current | kA | 63 | —— | 63 |
| 7 | Rated short circuit making current | kA | 63 | Limited by HV fuse | 63 |
| 8 | Rated short circuit breaking current | kA | —— | Limited by HV fuse | 25/25 |
| 9 | Rated transmission current | A | —— | 1700/1400 | —— |
| 10 | Rated active load breaking current | A | 630 | —— | —— |
| 11 | Rated closed‑loop breaking current | A | 630 | —— | 630 |
| 12 | Mechanical life‑load break switch/CB | Times | 10000 | 10000 | 20000 |
| Mechanical life‑Isolation/ground switch | Times | 5000 | 5000 | 5000 | |
| 13 | Circuit resistance | μΩ | ≤150 | —— | ≤150 |
| 14 | Rated charging pressure（20℃ gauge pressure） | MPa | 0.04 | 0.04 | 0.04 |
| 15 | Gas annual relative leakage rate | % | 0.05 | 0.05 | 0.05 |
| 16 | IP protection degree‑Cabinet | IP4X | IP4X | IP4X | |
| IP protection degree‑Gas tank | IP67 | IP67 | IP67 |
The operating mechanism uses spring charging technology to ensure stable switching performance.
For the load break switch-fuse combination unit or circuit breaker unit, the spring must be charged before switching operation. The operating handle is rotated clockwise for full charging, followed by pressing the green closing button to complete the closing operation.
The opening operation is performed by rotating the operating handle anticlockwise.
In transformer protection applications using vacuum circuit breakers, the circuit breaker can trip through the protection relay when abnormal conditions occur.
For load break switch-fuse combination units, the load break switch will trip when the fuse indicator operates under overcurrent or short-circuit conditions.
Usune 11kV SF6 GIS Gas Insulated Switchgear can be configured according to different medium-voltage distribution requirements, including:
● Transformer protection applications
● Industrial feeder systems
● Ring main distribution networks
● Commercial building power systems
● Compact substations
The sealed SF6 insulation design and reliable operating mechanism make the equipment suitable for applications requiring continuous operation and high safety standards.
Usune 11kv Sf6 Gis Gas Insulated Switchgear is designed for convenient transportation and site installation.
The equipment is equipped with lifting rings for crane transportation and can also be moved using forklift equipment. Different module combinations are designed with practical weight arrangements to simplify handling during project installation.
Before installation, customers should check the equipment condition after transportation, including:
● Operating handle availability
● Pressure indicator status
● Mechanical function operation
● Any visible transportation damage
The pressure indicator should remain within the normal green area before commissioning.
For safe and stable operation, the installation foundation should meet the following requirements:
● Ground bearing capacity should be at least 500kg/m²
● Installation surface should remain level and smooth
● Cable ducts should be prepared according to project requirements
● Cable ducts should be properly sealed to prevent moisture penetration
● Base steel channel dimensions should be prepared according to manufacturer drawings
Proper foundation preparation helps ensure accurate installation, reliable cable connection and long-term equipment performance.
| Comparison | Usune 11kV SF6 GIS | Traditional AIS |
| Insulation Method | SF6 gas insulated sealed structure | Air insulation |
| Environmental Protection | Less affected by dust, humidity and pollution | More dependent on installation environment |
| Safety | Mechanical interlocking and five safety protections | Protection depends on operation procedures |
| Installation Space | Compact design | Requires larger clearance |
| Maintenance | Reduced environmental maintenance requirements | Requires more environmental protection |
| Operation | Controlled switching sequence | Higher dependence on operator experience |
A customer used the Usune 11kV SF6 GIS for an industrial power distribution system where safe switching and limited installation space were key concerns. After installation, the customer highlighted the compact cabinet structure and mechanical interlocking, which made daily switching operations more controlled and reduced the risk of incorrect operation.
For a transformer protection application, the customer selected the vacuum circuit breaker configuration with relay-based protection. The customer found the automatic trip function and clear operating sequence helpful for responding to abnormal current conditions while simplifying routine operation.
During site operation, customers particularly valued the five safety interlock system. The required sequence between the cable door, grounding switch and load break switch made maintenance procedures clearer and helped prevent unsafe access to the cable compartment.
Zhejiang Usune Electric Co.,Ltd. has established a comprehensive management system according to ISO 9001 Quality Management System, ISO 14001 Environmental Management System and ISO 45001 Occupational Health and Safety Management System.
To meet international market requirements, Usune medium-voltage switchgear products have passed relevant IEC and GB standard type tests and applicable products have obtained CE certification. Strict quality control is implemented throughout manufacturing, inspection and testing processes to ensure reliable performance for global power distribution applications.
Mechanical interlocking prevents incorrect switching sequences between load break switches, circuit breakers and grounding switches. It helps protect operators and equipment during operation and maintenance.
Before installation, customers should check transportation conditions, pressure indicator status, operating handle availability and mechanical operation performance. Any damage or missing parts should be reported immediately.
It is suitable for transformer substations, industrial plants, commercial facilities, infrastructure projects and other 11kV medium-voltage distribution systems requiring reliable and safe operation.
Usune combines SF6 gas insulation technology, mechanical safety interlocking, reliable operating mechanisms and strict quality control to provide a safe and compact solution for modern 11kV medium-voltage distribution networks.
Address
No. 298, Wei 17th Road, Yueqing Economic Development Zone, Yueqing, Wenzhou City, Zhejiang Province, China
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