Product Overview
The LW8-40.5 outdoor SF6 circuit breaker is designed for 40.5kV installations exposed to lightning activity, with a defined lightning impulse withstand voltage rating as listed in the product attributes table. In outdoor switchyards connected to overhead lines, lightning-induced surges are a primary cause of insulation stress; the breaker’s insulation system is coordinated to withstand these transient overvoltages while providing high-speed fault clearing with SF6 gas arc extinguishing and a spring operating mechanism.
Key Features
- Lightning impulse withstand capability: The insulation system carries a lightning impulse withstand voltage rating (see the product attributes table), supporting surge coordination for overhead-line connected installations.
- 95kV power frequency withstand voltage: In addition to impulse performance, the breaker withstands 95kV power frequency voltage, covering sustained overvoltage conditions on the 40.5kV system.
- SF6 arc-extinguishing medium: Sulfur hexafluoride gas provides fast arc quenching and rapid dielectric recovery, important when the breaker must clear faults following lightning-induced flashovers.
- Spring operating mechanism: High-speed spring-charged operation minimizes fault duration, reducing damage from lightning-caused faults on connected equipment.
- Circuit-breaker failure and overcurrent protection: Integrated protection functions address breaker malfunction and overcurrent conditions arising from surge-related faults.
- Outdoor medium-mounted configuration: Three-pole outdoor design rated for 3000 mechanical operations, suited to switchyard structures in lightning-exposed areas.
- ISO9001-2000 certified with OEM/ODM support: Manufactured under ISO9001-2000 quality management with a 12-month warranty and MOQ of 1 piece.
Product Attributes
| Customization | Available |
| Breaking Capacity | High Voltage Circuit Breakers |
| Operation | Spring Operating Mechanism |
| Model NO. | LW8-40.5 |
| Speed | High-Speed Circuit Breaker |
| Arc-extinguishing Medium | SF6 |
| Installaton | Outdoor Installation |
| Poles Number | 3 |
| Type | Circuit Breaker |
| Function | Circuit-Breaker Failure Protection, Overcurrent Protection |
| Certification | ISO9001-2000 |
| Product Name | Hv Sulfur Hexafluoride Circuit Breakers |
| Service | OEM/ODM |
| MOQ | 1PCS |
| Warranty | 12 Months |
| Customize | Yes |
| Rated Voltage | 40.5kv |
| Lightning Impulse Withstand Voltage | 40.5kv |
| Power Frequency Withstand Voltage | 95kv |
| Rated Current | 1600/2000A |
| Mechanical Lifespan | 3000time |
| Rated Gas Pressure of Sulfur Hexafluorid | 0.5MPa |
| Alarm Pressure | 0.47MPa |
| Minimum Functional Pressure | 0.15MPa |
| Transport Package | Wood Box |
| Specification | Custom |
| Trademark | HaiRui |
| Origin | Zhejiang,China |
| Package Size | 1.00cm*1.00cm*1.00cm |
| Package Gross Weight | 1.000kg |
Applications
Suited to 40.5kV outdoor substations fed by overhead lines, rural distribution networks, and installations in lightning-prone regions. The breaker’s insulation coordination should be verified against the site’s lightning performance data and the insulation levels of connected transformers, cables, and surge arresters. Buyers should confirm rated current (1600A or 2000A) and coordinate surge protection schemes with the overall substation design.
Frequently Asked Questions
What is the lightning impulse withstand voltage?
The lightning impulse withstand voltage rating is listed in the product attributes table. This rating defines the transient overvoltage level the insulation system can withstand from lightning-induced surges on connected overhead lines.
Why does lightning performance matter for an outdoor circuit breaker?
Outdoor substations connected to overhead lines are directly exposed to lightning surges. The breaker’s insulation must coordinate with surge arresters and connected equipment so that lightning-induced transients do not cause insulation failure.
How is lightning protection coordinated in practice?
Surge arresters installed near the breaker limit incoming overvoltages, and the breaker’s impulse withstand rating provides the insulation margin above the arrester protective level. Verify coordination during substation design.
What other insulation rating does the breaker carry?
The breaker has a 95kV power frequency withstand voltage for sustained overvoltage conditions, in addition to its lightning impulse rating.
Can the breaker be customized for high-lightning-exposure sites?
Yes. OEM/ODM customization is available with ISO9001-2000 certification. Contact HaiRui with your site’s lightning exposure data, system voltage, and current requirements for a tailored configuration.
Get a Quote
To request a quotation for the LW8-40.5 lightning impulse withstand SF6 circuit breaker, contact HaiRui with your system voltage, rated current requirement, lightning exposure details, and order quantity.






FAQ
What is the lightning impulse withstand voltage?
The lightning impulse withstand voltage rating is listed in the product attributes table. This rating defines the transient overvoltage level the insulation system can withstand from lightning-induced surges on connected overhead lines.
Why does lightning performance matter for an outdoor circuit breaker?
Outdoor substations connected to overhead lines are directly exposed to lightning surges. The breaker's insulation must coordinate with surge arresters and connected equipment so that lightning-induced transients do not cause insulation failure.
How is lightning protection coordinated in practice?
Surge arresters installed near the breaker limit incoming overvoltages, and the breaker's impulse withstand rating provides the insulation margin above the arrester protective level. Verify coordination during substation design.
What other insulation rating does the breaker carry?
The breaker has a 95kV power frequency withstand voltage for sustained overvoltage conditions, in addition to its lightning impulse rating.
Can the breaker be customized for high-lightning-exposure sites?
Yes. OEM/ODM customization is available with ISO9001-2000 certification. Contact HaiRui with your site's lightning exposure data, system voltage, and current requirements for a tailored configuration.
Request Quote
Tell us your specifications, quantity, or application scenario and we will reply with a tailored quote.










