24kv 36kv Load Break Switch

The Usune Indoor 24kV 36kV Load Break Switch FLN36-24kV 36KV series is a core medium-voltage switchgear independently developed and manufactured by Zhejiang Usune Electric Co., Ltd. This series is specifically designed for indoor applications, adaptable to 24kV and 36kV rated voltages, and suitable for three-phase AC 50Hz ring networks and dual-radial power supply systems. Usune, a professional supplier rooted in China, integrates advanced technology and practical experience into every product, ensuring that the switches can stably handle load current and overload current switching, as well as the switching operations of long unloaded lines, unloaded transformers, and capacitor banks.

The core advantage of this series is its flexibility: when used with current-limiting fuses, it can replace circuit breakers. The load switch handles the switching of various load currents, while the current-limiting fuse handles the breaking of larger overload and short-circuit currents. This reduces the cost of power distribution equipment and improves the safety and stability of the power supply system, gaining widespread industry recognition.

Main Product Features

1. Advanced Structural Design

Adopting a double-break, three-position rotary contact design, the switch's operating position (closed, open, grounded) is clearly defined, effectively avoiding misoperation and ensuring precise and reliable switching; the overall three-phase installation design offers good synchronization, fewer parts, and convenient adjustment and installation, significantly reducing on-site installation difficulty and time.

2. Excellent Insulation Performance

The switch is sealed with upper and lower epoxy-cast housings, internally filled with SF6 gas at 0.045–0.07 MPa. SF6 gas possesses excellent insulation and arc-extinguishing properties, completely sealing the main circuit and grounding circuit within the housing, isolating it from external moisture, dust, and other contaminants. This ensures stable insulation performance even in harsh indoor environments, preventing insulation failures and guaranteeing the safe operation of the power system.

3. High Safety Performance

Safety is at the core of Usune's product design. In the event of internal arcing, the weak rear structure of the housing will automatically rupture, and simultaneously, the pressure relief valve on the top of the cabinet will open, expelling the overpressure gas outside the cabinet, effectively preventing cabinet explosion and protecting the safety of on-site operators and surrounding equipment. This design has passed multiple safety tests, complies with international safety standards, and provides reliable protection for power distribution operations.

4. Flexible and Reliable Operation

The Indoor 24kV 36kV Load Break Switch supports both manual and electric operation modes, selectable according to actual site requirements. It is convenient and reliable to operate, with a streamlined mechanical structure and stable performance, adaptable to frequent switching operations. Adopting a maintenance-free design, it boasts a long service life, with a mechanical lifespan of up to 2000 cycles, reducing subsequent maintenance costs and workload.

Technical Parameters

Usage Conditions

To ensure stable and reliable operation, the Usune Indoor 24kV 36kV Load Break Switch must be used under the following conditions (based on actual application experience in China and globally):

(a) Altitude: Not exceeding 1000 meters;
(b) Ambient temperature: Upper limit +40℃, lower limit -25℃;
(c) Relative humidity: Daily average ≤95%, monthly average ≤90%;
(d) No significant corrosive gases, flammable gases, or water vapor pollution in the surrounding air;
(e) No frequent or severe vibration.

Project Reference

Cas-space Rocket Launch Project

Test Report

Real-world Application Case

Case Study: Hangzhou Urban Residential Power Distribution Project, China

A large residential area in Hangzhou, China, had high requirements for energy efficiency, safety, and stability in its indoor power distribution rooms. The project selected 20 Usune indoor 24kV load break switches (FLN36-24kV series) to handle load switching and protection for the residential power supply system. As the designated supplier for this project, Usune provided customized installation guidance and after-sales service. The factory rigorously tested each product before shipment to ensure compliance with project technical requirements. Since its commissioning in 2023, the switches have operated stably without insulation faults or malfunctions, effectively ensuring a stable power supply for over 5,000 households. The project team highly praised the product performance and Usune's professional services.

FAQ

Q1: Can the Usune Indoor 24kV 36kV Load Break Switch be used alone to interrupt short-circuit current?

A1: No. Load switches are primarily used for switching load currents and overload currents, as well as connecting and disconnecting unloaded long lines, unloaded transformers, and capacitor banks. They cannot independently interrupt short-circuit currents. To handle short-circuit currents, load switches can be combined with current-limiting fuses. The current-limiting fuses handle the interruption of larger overload and short-circuit currents, and this combination can replace circuit breakers, providing comprehensive protection for the power supply system. This design, optimized by Usune based on years of professional experience, balances cost and safety.

Q2: What should be done if the SF6 gas pressure of the load switch is too low?

A2: The SF6 gas in Usune indoor 24kV and 36kV load switches is sealed within an epoxy-cast housing. The standard pressure is 0.045–0.07MPa. Low pressure will affect the switch's insulation and arc-extinguishing performance. Users should first check for gas leaks. If a leak is found, contact the Usune after-sales team immediately. As a professional manufacturer, Usune provides expert gas leak detection and repair services. After eliminating the leak, SF6 gas needs to be replenished to the standard pressure to ensure the switch operates normally. It is recommended to check the gas pressure regularly during daily use.