Product Overview
The LW9-72.5 is an outdoor high-voltage SF6 circuit breaker with a rated short-time withstand current of 40kA for 3 seconds and a peak withstand current of 100kA. These ratings ensure the breaker can carry fault currents without thermal or mechanical damage before the protection relay initiates breaking. Designed for 72.5kV systems, it uses SF6 gas for arc extinguishing and a spring mechanism for high-speed switching.
Key Features
- 40kA short-time withstand for 3 seconds: The breaker carries 40kA fault current for 3 seconds without damage, providing time margin for protection relay coordination before breaker operation is initiated.
- 100kA peak withstand current: Withstands the initial peak asymmetrical fault current of 100kA, ensuring mechanical stability of the interrupter and support structure during the first fault cycle.
- 40kA short-circuit breaking current: Clears fault currents up to 40kA with high-speed operation, interrupting the fault before sustained thermal damage to downstream equipment.
- SF6 arc-extinguishing medium: Sulfur hexafluoride gas provides efficient arc quenching with fast dielectric recovery, suitable for repeated fault clearing duty in outdoor installations.
- 72.5kV rated voltage with 350kV lightning impulse withstand: Designed for 72.5kV systems with lightning impulse withstand of 350kV to earth, providing insulation coordination for overhead line and substation protection.
- Spring operating mechanism: Spring-charged mechanism ensures consistent high-speed contact separation, minimizing the duration of fault current flow before interruption.
- ISO9001-2000 certified with OEM/ODM support: Manufactured under ISO9001-2000 quality management. Customization available for current, voltage, IP level, and dimensions. Factory located in Wenzhou, Zhejiang, China with 24-hour English technical support.
Basic Info.
| Model NO. | LW9-72.5 |
| Arc-extinguishing Medium | SF6 |
| Structure | Other |
| Type | Circuit Breaker |
| Certification | ISO9001-2000 |
| Service | OEM/ODM |
| Warranty | 12 Months |
| Rated Voltage | 72.5kv |
| Rated Short-Time Withstand Current | 40ka(3s) |
| Rated Peak Withstand Current | 100ka |
| Cut Back-to-Back Capacitor Bank Curr | 4000A |
| Rated 1 Min Power Frequency Withstand Vo | Fracture:160+42kv to Earth:160kv |
| Specification | Custom |
| Origin | Zhejiang,China |
| Speed | High-Speed Circuit Breaker |
| nstallation | Outdoor Installation |
| Poles Number | Other |
| Function | Circuit-Breaker Failure Protection |
| Product Name | Hv Sulfur Hexafluoride Circuit Breakers |
| MOQ | 1PCS |
| Customize | Yes |
| Rated Current | 4000A |
| Rated Short-Circuit Breaking Current | 40ka |
| Rated Lightning Impulse Withstand Voltag | Fracture:350+60kv to Eath:350kv |
| Cut Combined Reactor Current | 3150A |
| Transport Package | Wood Box |
| Trademark | HaiRui |
Packaging & Delivery
| Package Size | 1.00cm*1.00cm*1.00cm |
| Package Gross Weight | 1.000kg |
Applications
Suitable for 72.5kV outdoor substations where fault current levels and protection relay coordination times require a breaker with high short-time withstand capability. The 40kA/3s rating supports applications where delayed tripping may occur due to relay grading margins. Buyers should confirm the substation’s maximum fault current, relay coordination time, and the required short-time withstand duration before selecting the breaker.
Frequently Asked Questions
What is the short-time withstand current rating?
The rated short-time withstand current is 40kA for 3 seconds. The breaker also has a peak withstand current of 100kA, ensuring stability during the initial asymmetrical fault peak.
How does the short-time withstand rating affect protection coordination?
The 40kA/3s rating allows the breaker to carry fault current for the time required by downstream protection relays to operate selectively, before the breaker itself interrupts the fault at 40kA breaking capacity.
What is the rated voltage?
The rated voltage is 72.5kV, with a lightning impulse withstand voltage of 350kV to earth and a power frequency withstand voltage of 160kV to earth.
What is the arc-extinguishing medium?
The breaker uses sulfur hexafluoride (SF6) gas as the arc-extinguishing medium, providing fast arc quenching and dielectric recovery for outdoor high-voltage switching.
Can the short-time withstand rating be customized?
OEM/ODM customization is available for rated current, voltage class, and other parameters. Contact the manufacturer with your project’s fault current levels and protection coordination requirements for a tailored solution.
Get a Quote
To request a quotation or discuss customization for the LW9-72.5 SF6 circuit breaker, contact HaiRui with your project specifications including rated voltage, current requirements, fault current levels, installation environment, and quantity needed.
FAQ
What is the short-time withstand current rating?
The rated short-time withstand current is 40kA for 3 seconds. The breaker also has a peak withstand current of 100kA, ensuring stability during the initial asymmetrical fault peak.
How does the short-time withstand rating affect protection coordination?
The 40kA/3s rating allows the breaker to carry fault current for the time required by downstream protection relays to operate selectively, before the breaker itself interrupts the fault at 40kA breaking capacity.
What is the rated voltage?
The rated voltage is 72.5kV, with a lightning impulse withstand voltage of 350kV to earth and a power frequency withstand voltage of 160kV to earth.
What is the arc-extinguishing medium?
The breaker uses sulfur hexafluoride (SF6) gas as the arc-extinguishing medium, providing fast arc quenching and dielectric recovery for outdoor high-voltage switching.
Can the short-time withstand rating be customized?
OEM/ODM customization is available for rated current, voltage class, and other parameters. Contact the manufacturer with your project's fault current levels and protection coordination requirements for a tailored solution.
Request Quote
Tell us your specifications, quantity, or application scenario and we will reply with a tailored quote.
