FZN21-40.5 Indoor Load Break Switch | 33kV Medium Voltage Switch
FZN21-40.5 Indoor Load Break Switch | 33kV Medium Voltage Switch is a reliable indoor switching device designed for 33kV medium-voltage distribution systems, with a 40.5kV insulation class. It provides safe load switching, circuit isolation, and grounding through a compact three-position design.
Featuring an SF₆ gas-insulated structure, sealed enclosure, and manual or motorized operating mechanism, the FZN21-40.5 offers stable insulation performance, low maintenance requirements, and reliable operation. It is suitable for indoor switchgear, RMUs, substations, industrial plants, and utility distribution networks.
Get a QuoteOverview
The FZN21-40.5 Indoor Load Break Switch is a high-voltage switching device designed for 33kV medium-voltage distribution systems, with a rated voltage of 40.5kV. It provides reliable load switching, circuit isolation, and grounding for indoor power distribution applications.
Featuring a compact gas-insulated structure and three-position operation (ON / OFF / EARTH), the FZN21-40.5 helps improve operational safety while reducing installation space and maintenance requirements. It is suitable for indoor switchgear cabinets, RMUs, substations, industrial plants, and utility distribution networks requiring dependable switching and isolation at 33–40.5kV.
Key Features
- 33kV Distribution Application
Designed for 33kV medium-voltage distribution systems with a 40.5kV insulation class, providing reliable switching and isolation. - SF6 Gas-Insulated Design
Uses SF₆ insulation and arc-extinguishing technology to provide stable dielectric performance and reliable load interruption. - Flexible Operating Mechanism
Available with a manual or motorized spring operating mechanism, supporting different switchgear control requirements. - Three-Position Operation
Provides clear ON / OFF / EARTH positions for switching, isolation, and grounding, helping improve operational safety. - Sealed SF6 Enclosure
Factory-filled and sealed SF₆ enclosure helps maintain stable insulation performance and reduces exposure to external environmental conditions. - Low-Maintenance Operation
Designed for long-term operation with reduced routine maintenance requirements, with maintenance-free service of up to 10 years under specified conditions. - Indoor Switchgear Compatibility
Suitable for integration into indoor switchgear cabinets such as KYN61 and XGN15, providing a compact solution for 33kV distribution applications.
Technical Data
| Item | Unit | Parameter | |
| Rated Voltage | kV | 40.5 | |
| System Voltage | 33 | ||
| Rated Current | A | 1250 | |
| Breaking Current (Load) | 1250 | ||
| Making Current | kA | 31.5 | |
| Peak Withstand Current | 80 | ||
| SF6 Gas Pressure | MPa | 0.4 – 0.5 | |
| Insulation Level | / | 95kV (BIL) | |
| Mechanical Life | Times | ≥ 5000 | |
Compliance & Certifications
The FZN21-40.5 Indoor Load Break Switch is designed to meet applicable high-voltage switching requirements and can be supplied with relevant documentation for project qualification and export applications.
- GB 3804 – High-voltage AC load break switches
- IEC 60265-1 – High-voltage switches for rated voltages above 1kV
- IEC 62271-103 – High-voltage AC switching devices
- ISO 9001 / ISO 14001 / ISO 45001 – Quality, environmental, and occupational health & safety management systems
- CE Conformity – Available for applicable export configurations
- Factory Test Reports – Available according to the product configuration and project requirements
Application Scenarios
The FZN21-40.5 is suitable for a range of 33kV indoor medium-voltage distribution applications, including:
- 33kV Indoor Switchgear Cabinets
Used in distribution networks for reliable load switching, isolation, and grounding. - Utility Substations & Smart Grid Feeders
Supports feeder switching and sectionalizing in modern distribution systems. - Medium-Voltage RMUs
Its compact three-position structure is suitable for ring main unit configurations. - Industrial Plant Supply Panels
Provides reliable switching and isolation for industrial medium-voltage power distribution. - Transformer Protection Units
Can be combined with appropriate fuses for transformer and feeder protection applications.
