SF6 Load Break Switches & Surge Arresters
XBRELE delivers high-reliability FLN36-12 SF6 Switches for Ring Main Units (RMU) and precision-engineered Zinc Oxide Surge Arresters. Our integrated solutions ensure safe load breaking, arc quenching, and superior overvoltage protection for MV distribution networks.
Core Control & Protection for Medium Voltage Distribution
XBRELE provides essential active components for network reliability. Our FLN36-12 SF6 Load Break Switches serve as the primary switching device in Ring Main Units (RMU), utilizing Sulphur Hexafluoride (SF6) gas for efficient arc quenching and insulation. They are critical for load management in 12kV to 24kV power distribution systems.
For overvoltage protection, we offer high-performance Zinc Oxide Surge Arresters (HY5WS/HY5WR series). These gapless polymer-housed arresters feature superior non-linear volt-ampere characteristics, rapidly responding to lightning and switching surges to protect transformers, capacitor banks, and switchgear from insulation breakdown.
Engineered for safety and longevity, our switches utilize a reinforced epoxy resin insulating shell to ensure a leak-free gas environment. Compliant with standards such as IEC 60265-1 (Switches) and IEC 60099-4 (Arresters), our MV switching and protection components deliver stable operation in diverse grid conditions.
For a complete range of insulators, bushings, and other switchgear components, please visit our main Switchgear Parts & Accessories pillar page .
Switching & Protection
Critical core components for RMU and distribution protection. High reliability SF6 switches and Zinc Oxide Arresters.

- Voltage 12kV
- Medium SF6 Gas
- App RMU Cabinet

- Material Epoxy Resin
- Type Insulating Housing
- Size 643×210 mm

- Rated 12.7 / 17 kV
- Residual 50kV
- Type Distribution

- Rated 5 / 10 kV
- Residual 13.5 / 27kV
- Type Distribution

- Rated 5 / 10 kV
- App Capacitor Bank
- Type Protection
Core Technologies of XBRELE Switching & Protection Series
Reliability is paramount in medium voltage networks. Our FLN36-12 SF6 Load Break Switches feature a hermetically sealed epoxy shell for leak-free performance, while our Zinc Oxide Surge Arresters provide nanosecond response times to overvoltage events. For a complete range of switchgear components, visit our Switchgear Parts pillar page .
SF6 Gas Insulation & Arc Quenching
The FLN36-12 Load Break Switch utilizes Sulphur Hexafluoride (SF6) gas, known for its exceptional dielectric strength and arc-extinguishing properties.
- Sealed Epoxy Housing: The switch body is cast from high-strength epoxy resin, ensuring a gas-tight environment for safe operation.
- Efficient Load Breaking: Designed to safely interrupt rated currents and fault currents (when fused) in RMU cabinets.
- Maintenance-Free: The sealed gas system prevents contact oxidation and extends the operational lifecycle.
Zinc Oxide (ZnO) Non-Linear Characteristics
Our HY5W Series Surge Arresters employ premium Zinc Oxide varistors, offering superior protection compared to traditional SiC arresters.
- Gapless Design: Eliminates spark gaps for faster response times and steeper protective characteristics.
- Steep-Front Response: Instantly clamps voltage surges from lightning or switching operations, protecting sensitive transformers.
- High Energy Absorption: Capable of handling significant surge energy without thermal runaway.
Rigorous Testing for Safety Compliance
Every critical component undergoes strict factory testing to ensure compliance with IEC standards and operational safety.
- Gas Leakage Testing: 100% helium leak detection for SF6 switch shells to guarantee long-term sealing integrity.
- Residual Voltage Test: Verification of arrester clamping voltage to ensure optimal protection levels.
- Mechanical Endurance: Switches are tested for thousands of operating cycles to verify mechanism reliability.
Manufacturing Excellence for Grid Reliability
XBRELE employs state-of-the-art manufacturing for SF6 Load Break Switches and Zinc Oxide Surge Arresters. From gas-tight epoxy casting to precision polymer injection, every step ensures operational safety and longevity in 12-24kV distribution networks.
Assembly & Gas Filling Process (FLN36)
Our SF6 switch production line integrates automated shell casting, contact assembly, and vacuum gas filling to guarantee zero leakage and consistent arc-quenching performance.
- 01
Epoxy Shell Casting
High-strength epoxy resin is cast using APG technology to form the hermetic switch housing, ensuring mechanical robustness and gas tightness.
- 02
Mechanism Assembly
Internal contacts and operating mechanisms are precisely assembled within the shell. Clean-room conditions prevent particle contamination.
- 03
Vacuum Drying & Gas Filling
The unit is vacuum-dried to remove moisture, then filled with high-purity SF6 gas to the rated pressure for optimal insulation.
- 04
Helium Leak Detection
100% of switches undergo helium mass spectrometry leak testing to ensure annual leakage rates are far below IEC standards.
- 05
Final Operational Test
Mechanical operation cycles (Open/Close/Earth) and resistance measurements verify the load break switch is ready for RMU installation.
Routine & Type Tests
Our components are tested against IEC 60265 (Switches) and IEC 60099-4 (Arresters) to ensure grid protection integrity.
SF6 Switch Performance
- Gas Tightness: Leakage rate < 0.1% per year verified by rigorous helium testing.
- Loop Resistance: Ensures low contact resistance to minimize heat rise under load.
- Mechanical Endurance: Verified for 2,000+ CO operations (M1 class) reliability.
Surge Arrester Verification
- Reference Voltage (U1mA): Checks the varistor turn-on point accuracy.
- Residual Voltage: Confirms clamping capability under 8/20µs lightning impulse current.
- Seal Integrity: Polymer housing is tested for moisture ingress protection (IP67 equivalent).
Material Quality
- ZnO Varistors: High-energy absorption capacity and stable aging characteristics.
- Epoxy Resin: High Tg ensuring thermal stability in sealed gas environments.
Global Supply of Grid Protection Components
XBRELE understands the critical nature of FLN36-12 SF6 switches and Surge Arresters. We provide secure transport solutions, rapid replacement services, and technical configuration support for RMU manufacturers and utility maintenance teams worldwide.
Stock & Quick Turnaround
We maintain stock of standard FLN36-12 switches and common HY5WS arrester models to minimize downtime for grid maintenance.
- Quick Ship: Standard arrester models available for immediate dispatch.
- Production Speed: 15-day lead time for batch orders of SF6 Load Break Switches.
- Emergency Response: Expedited air freight options for urgent substation repairs.
- Spare Parts: Availability of operating mechanisms and auxiliary contacts.
Configuration & Technical Support
Our engineering team assists panel builders in selecting the right switch configuration and arrester ratings for specific grid conditions.
- Switch Configuration: Options for manual or motorized operation (110V/220V).
- Fuse Selection: Guidance on matching fuse links for FLN36-12 combination units.
- Arrester Sizing: Calculation support for continuous operating voltage (Uc) and rated voltage (Ur).
- Installation Guide: Detailed manuals for safe SF6 switch handling and installation.
Specialized Transport Packaging
SF6 switches and ceramic/polymer components require specialized handling to prevent gas leakage or mechanical damage during transit.
- Gas Pressure Safety: Switches shipped with positive SF6 pressure, verified before crating.
- Impact Protection: Heavy-duty wooden crates with shock-absorbing foam for all switch units.
- Moisture Barrier: Surge arresters are sealed in moisture-proof bags to maintain insulation properties.
- Safety Compliance: Full MSDS and non-dangerous goods certification for SF6 transport.
Common Questions About LBS & Arresters
Expert answers on selecting SF6 load break switches for RMU panels and choosing the correct surge arrester ratings for transformer protection.
