Internal component details

Internal constitutions:

Operating Mechanism – Mechanical system for operating the breaker's opening and closing.

Terminals (Fixed Type) – Electrical connection points for permanent wiring.

Vacuum Interrupter – Main arc-quenching chamber containing contacts and ceramic insulation.

Contact Arm (Drawout Type) – Movable conductive part in withdrawable breakers.

Silver-Plated Copper Contacts – Improve electrical conductivity and resist corrosion.

Drawout Chassis – Frame structure for supporting removable breaker components.

Insulating Cylinder – Protective insulating enclosure for the vacuum interrupter.

Aviation Connector – Rugged, quick-release plug connector.

Finger Cluster Contacts – Multi-finger contact system for reliable electrical connection.

Internal parts

Product quality

Quality of important components of the product

	Vacuum Interrupter (Vacuum Tube) Sealed Enclosure: Constructed from high-strength ceramic or glass, this housing maintains a permanent high vacuum, which is the fundamental principle enabling its arc-quenching function. Movable & Fixed Contacts: Housed internally, these contacts are made from specialized materials such as copper-chromium alloy. They maintain integrity under high arcing temperatures and feature a low chopping current level. Arc Shield: A critical internal component. It ensures a uniform electric field distribution, absorbs metal vapor produced during arcing, and protects the insulating envelope from contamination.
Insulating Cylinder Material: Typically manufactured using the Automated Pressure Gelation (APG) process with high-performance epoxy resin, incorporating embedded metal connectors. High Insulation Strength: Designed to consistently withstand power frequency and impulse voltages significantly exceeding the system's operating voltage. High Mechanical Strength: Capable of enduring substantial thrust, tension, and impact forces during breaker operation without deforming or fracturing. High Dimensional Stability: Resistant to deformation from temperature and humidity variations, ensuring precise transmission and consistent stroke reliability.
	Plum blossom contact Conductivity: Made of high-purity, high conductivity silver plated copper. The silver plating layer is thick and uniform, which can effectively reduce contact resistance and prevent oxidation Elasticity: High performance elastic alloys such as high-quality tin phosphorus bronze or beryllium bronze are used to ensure that there is no fatigue or relaxation after long-term use. Structural strength and wear resistance: The structure is sturdy, and the thickness of the "petal" root is sufficient. The surface is usually subjected to wear-resistant treatment to prevent poor contact caused by mechanical wear.

Quality Details

Product Installation

Product application scenarios

Key Protection for Power Generation, Transmission & Distribution Networks

• Power Plants: Safeguards generator terminals and in-plant electrical systems.

• Substations (Primary Application): Deployed in 10kV-35kV (medium voltage) distribution substations to act as the protection and control switch for critical assets such as outgoing feeders, busbars, capacitors, and transformers. In the event of a system fault like a short circuit, it can interrupt fault currents within milliseconds.

The Entry Point for Industrial & Commercial Users
Serves as the main circuit breaker in high-voltage switchgear (e.g., main incoming, contactor, and feeder cabinets) within factories, large buildings, data centers, and hospitals. It manages normal power supply flow and trips instantaneously during internal faults to prevent escalation.

Frequent Operation & Special Load Control

• Capacitor Bank Switching: Ideal for frequent switching of reactive power compensation capacitors due to its superior capacitive current breaking performance and extended operational life.

• Motor Control: Used for starting and stopping large high-voltage motors.

Production line

Factory real shooting

Product testing

1.Mechanical Characteristic Testing

This verifies the operating action performance of the breaker.

• Travel & Overtravel Test:

Total Travel: Measures the full displacement of the moving contact from the closed to the open position.

Overtravel: Measures the continued spring compression displacement of the contact after closing, ensuring reliable contact pressure and sufficient allowance for electrical wear.

• Contact Gap (Open Distance) Test:

Measures the minimum insulation distance between contacts after opening. This distance must be sufficient to ensure reliable insulation withstand.

• 3-Phase Synchronization Test (Opening/Closing):

Measures the time difference between the opening or closing of the three poles. The requirement is an extremely small interval (e.g., <2ms) to reduce switching overvoltage and ensure balanced current interruption.

2. Electrical Performance Testing

This verifies current-carrying and breaking capacity.

• Contact Resistance (Millivolt Drop) Test:

Applies a DC current (typically 100A) to the breaker and measures the milliohm resistance of its main current path (including contacts). The value must be very low and stable to prevent abnormal heating during operation.

• High-Current Tests (Temperature Rise & Withstand):

  • Temperature Rise Test: Applies rated current continuously to verify the steady-state temperature rise of all parts remains within limits.

  • Short-Time Withstand Current Test: Applies a high short-circuit current for a short duration (e.g., thermal 4s, dynamic peak) to verify its ability to withstand electromagnetic forces and thermal effects without damage.

• Overload & Operating Duty Tests:

  • Overload Test: Verifies performance under specified overload current conditions.

  • Operating Duty Test: Verifies the mechanism reliably opens and closes at specified minimum and maximum control voltages.

3. Insulation & Protection Function Testing

• Dielectric Withstand Tests:

  • Power Frequency Withstand Voltage: Applies an AC high voltage significantly above the rated voltage (e.g., 42kV for 1 min) across open contacts and to earth, verifying the main insulation does not flashover or break down.

  • Impulse Withstand Voltage: Applies standard lightning or switching impulse voltage waves to verify the ability to withstand transient overvoltages.

• Protective Function & Auxiliary Characteristic Tests:

  • Undervoltage Release Test: Verifies the breaker trips automatically and reliably when the supply voltage falls below a set threshold.

  • Contact Bounce Test: Measures the duration of any brief, unwanted contact separation caused by impact during the closing operation.

Packaging

Outerpackaging:

Strong wooden boxes are usually used to provide sufficient mechanical strength.

Wooden crate suitable for large circuit breakers or international transportation

Inner packaging:

Wrap the circuit breaker with buffer materials such as foam pad, bubble film or pearl cotton to prevent vibration and collision.

For large circuit breakers, the packaging box may adopt a layered design, with accessories (such as manuals, tools, spare parts) placed on the upper layer

Upgraded Packaging

Strengthening of cover plate structure Upgrade the original thinner cover plate to a thicker plate, significantly improving its compressive strength and avoiding deformation or damage caused by external impact. Add support columns at the edges Add reinforced support columns at key stress locations on the edges of the box to enhance overall structural stability and prevent edge cracking or box distortion. Overall load-bearing performance improvement By adding thicker cover plates and edge supports, the load-bearing capacity of the wooden box is significantly increased, making it suitable for heavier or more protective goods.

Shipping

If there is a designated freight forwarder in china, we willtransport the products to the designated location through road transportation or domestic express delivery after production is completed

International transport

When the quantity of goods is small and time is tight, and it needs to be transported to a designated location abroad, the three majorinternational express delivery companies are selected for transportation DHL,FEDEX,UPS

Sea freight/air freight

When there is a large quantity of goods and time is not urgent, we choose sea freight. We will choose a suitable freight company, who wil arrange for trucks to pick up the goods and transport them to the designated por for warehousing. Finaly, they will transpored by sea to the customer's desianated port, and the customer needs to pick up the goods with a bill of lading.

Customer feedback

Certificate​

FAQ

Q: What is the voltage/current range of this product? What is its breaking capacity?

A: Please contact customer service for details.

Q: What is the minimum order quantity? Do you accept sample orders?

A: The minimum order quantity is 1 set, and we accept sample orders.

Q: What is the warranty period? How do I apply for a warranty?

A: The product warranty is 1 to 2 years. Please contact customer service directly to apply.

Q: Do you have CE, RoHS, UL, or other certifications? Can you provide certificates?

A: We have CE and RoHS certifications and can provide certificates.

Q: Does the price include tax/shipping?

A: The price does not include shipping/tax.

Q: What notable clients or project examples have you worked with?

A: State Grid Corporation of China, Chint Group.