33kv Indoor Vcb Vacuum Circuit Breaker

The Usune 33kv Indoor Vcb Vacuum Circuit Breaker is a new generation product designed based on advanced switchgear R&D concepts and the actual needs of the global power distribution market. It is suitable for three-phase AC 50Hz indoor power distribution systems with a rated voltage of 40.5kV (33kV operating level), undertaking core functions such as normal load switching, fault current interruption, system overload protection, and equipment safety isolation.

The product abandons complex and redundant structures, adopting an integrated frame and modular layout, optimized for fixed side-mount installation within high-voltage switchgear. It offers significant advantages in cabinet space adaptation, overall structural stability, and later operation and maintenance. Compared to conventional indoor vacuum circuit breakers, it is more adaptable to frequent operating conditions, has a longer mechanical life, and more stable operation consistency, fully meeting the continuous and reliable operation requirements of critical power supply links.

Core Product Advantages

1. Professional R&D + Scenario-Based Design

Developed specifically to address the pain points of practical applications in 33kV/40.5kV indoor switchgear, it adopts professional switch design logic. Its mechanical output characteristics are perfectly matched to the operational requirements of the vacuum interrupter. All structural and performance configurations are designed for indoor fixed installations, frequent operations, substations, and industrial power distribution scenarios. The technology is mature and highly practical for engineering applications.

2. Real-World Testing + Stable Application Feedback

The 33kV Indoor Vcb Vacuum Circuit Breaker uses a mature modular spring operating mechanism. Its transmission structure is simple and reliable, with no complex or easily damaged transmission links. Verified in numerous industrial power distribution, substation upgrades, and mining power supply projects, it demonstrates excellent performance in closing and opening accuracy, mechanical lifespan, and anti-interference capabilities.

3. Standardized Performance + Complete Supporting Parameters

The operating coil, energy storage motor, and operating logic are all designed according to rated parameters. The voltage adaptation range is clear, and the auxiliary switch linkage logic is reliable. The product's closing, opening, and energy storage operations are standardized, with complete dimensions, interfaces, and wiring configurations. It can be directly matched with standard 33kV indoor switchgear, offering strong compatibility and high replaceability.

4. Safe, Stable, and User-Friendly Design

Equipped with dual electric/manual energy storage modes, the status indicator and auxiliary switch are synchronized. A hydraulic buffer absorption design is used in the later stages of tripping, effectively reducing impact wear and improving operational safety. It provides clear feedback on energy storage and opening/closing status, avoiding the risk of misoperation and comprehensively ensuring on-site operation and maintenance safety.

Operating Structure and Mechanical System

The core of the Usune ZN85C-40.5 33kV Indoor Vcb Vacuum Circuit Breaker uses a dedicated modular spring operating mechanism, which is installed entirely inside the equipment frame and is an indispensable core component of the circuit breaker's overall structure. This mechanism is specifically designed for 40.5kV indoor fixed-side-mounted models, with a highly simplified transmission structure and a more rational force distribution.

Its most significant structural highlight is its perfect adaptation to the circuit breaker's vertical layout, allowing for highly integrated assembly with the main circuit and pole system. The mechanism's output force curve perfectly matches the vacuum interrupter's operational requirements, avoiding problems such as mismatched operating speeds, unstable contact pressure, and short mechanical lifespan caused by conventional mechanisms. It is particularly suitable for the mechanical characteristics and operating conditions of 40.5kV indoor vacuum circuit breakers.

Working Principle and Operation Flow

1. Energy Storage Operation

The circuit breaker's closing power is entirely provided by the closing spring's energy storage, supporting both electric motor drive and manual handle operation modes. Even during power outages or maintenance, it ensures normal energy storage and backup closing.

In electric energy storage mode, the energy storage motor fixed to the side plate of the mechanism drives the gear transmission system. In manual energy storage mode, the operator pulls a dedicated energy storage handle, rotating the gear shaft and gear assembly. Through the overrunning clutch, the energy storage shaft rotates synchronously, stretching the closing spring to complete energy storage.

Upon reaching full energy storage, the energy storage pawl securely locks the cam roller, and the overrunning clutch automatically disengages. Simultaneously, the connecting plate drives the energy storage indicator to flip, displaying the "energy stored" indicator, and the auxiliary switch switches to cut off the motor power. At this point, the circuit breaker enters the closing-ready state, with a clear and reliable status.

2. Closing Operation

Closing can be achieved by manually pressing the closing button or remotely controlling the closing electromagnet. Upon triggering, the energy storage mechanism releases the pawl lock, and the pre-stored closing spring rapidly contracts, causing the cam, energy storage shaft, and overrunning clutch to move synchronously.

The cam further drives the linkage mechanism, pushing the insulated pull rod and moving contact towards the closing position, compressing the contact disc spring, and establishing the stable contact pressure required for rated current conduction. After closing, the closing pawl locks the mechanism roller, maintaining the closed position; the energy storage indicator and auxiliary switch automatically reset, connecting the motor circuit. With an external power supply, it immediately enters the re-energy storage state, the closing/opening indicator switches to the "closed" state, and the main and auxiliary switches complete synchronous switching.

3. Tripping Operation

Trip can be triggered in three ways: manually via the trip button, via an external electrical trip unit, or via an overcurrent trip unit. Upon triggering, the closing latches unlock, releasing the locking state between the mechanism and the rollers.

Under the combined action of the contact spring and the tripping spring, the moving and stationary contacts within the vacuum interrupter chamber of the fixed pole quickly and reliably separate, achieving fault current or load current interruption. In the later stages of the tripping action, the built-in hydraulic buffer absorbs residual impact energy, limiting the final tripping position, reducing mechanical impact noise and wear, and extending the overall mechanical life of the equipment.

Key Electrical and Mechanical Parameters

Installation Method and Dimensions

The Usune ZN85C-40.5 adopts a fixed side-mounted installation structure, specifically designed for standard indoor high-voltage switchgear. It features high cabinet compatibility, convenient assembly, commissioning, and subsequent maintenance, and supports three mainstream wiring installation methods:

- Right-side outgoing cable type
- Top-incoming cable type
- Recessed installation type

The overall dimensions strictly adhere to the overall unit matching specifications (see Figure 1 for detailed mounting hole spacing, overall length, width, height, and busbar connection dimensions), enabling standardized replacement and unified cabinet matching, reducing customer design, modification, and installation costs.

FAQ

Q1: Is this product suitable for both 33kV and 40.5kV power systems?

A: Yes. The product's rated design voltage is 40.5kV, fully meeting the conventional indoor operation requirements of 33kV power systems. It has sufficient insulation and breaking capacity margins, and can be safely and stably applied to 33kV indoor switchgear projects in industrial and mining enterprises, power plants, and small and medium-sized substations.

Q2: What if the on-site power supply is interrupted and energy storage cannot be completed electrically?

A: This 33kV Indoor Vcb Vacuum Circuit Breaker is equipped with a dedicated manual energy storage handle. When the external power supply is interrupted or the motor fails, the operator can manually complete the closing and energy storage operation through the energy storage handle, achieving normal closing operation and significantly improving the equipment's emergency operation capability under power outage and maintenance conditions.

Q3: What are the core advantages of this fixed side-mounted type compared to conventional handcart-type vacuum circuit breakers?

A: This side-mounted fixed model has stronger structural rigidity and less radial installation space, making it easier to match with compact switchgear. It also offers higher stability under frequent operation and vibration conditions. Installation, fixing, and subsequent maintenance are simpler, making it more suitable for industrial users, retrofit projects, and non-fully drawer-type replacement scenarios with high requirements for fixed and reliable operation.