Product Overview
When a fault occurs on a 126kV network, the circuit breaker may need to carry the full short-circuit current for several seconds while backup protection completes its sequence. The LW36-126 is rated for exactly this scenario: a 40kA/3s short-time withstand current that lets the breaker stay closed, thermally stable and mechanically intact, until the protection scheme clears the fault. Combined with its 40kA breaking capacity, this makes it a high-precision protection device for substations where backup clearing times matter.
Rated at 126kV and 3150A with SF6 arc extinguishing and a high-speed operating mechanism, the breaker delivers precise, repeatable switching performance in outdoor installations. The 3-pole design, ISO9001-2000 certified manufacture, and OEM/ODM flexibility round out a specification aimed at protection engineers who design around withstand and timing margins.
Key Features
40kA/3s short-time withstand rating
The breaker carries full fault current for three seconds without damage, covering delayed backup protection clearing sequences and auto-reclose dead times.
Precise high-speed switching
Classified as a high-speed circuit breaker, its operating mechanism provides fast, repeatable contacts travel, supporting accurate coordination with protection relays.
40kA short-circuit breaking capacity
The same 40kA capability applies to interruption duty, so the breaker both survives and clears the maximum specified fault level.
SF6 dielectric and arc-quenching system
Sulfur hexafluoride gas maintains insulation strength between operations and quenches the arc efficiently at every current zero.
Protection-oriented function set
Specified for circuit-breaker failure protection and overcurrent protection duties, giving scheme designers a dependable final switching element.
Outdoor 3-pole arrangement
Installed in open-air switchyards, the three-pole breaker is engineered for continued precision across seasonal temperature and humidity ranges.
Basic Info.
| Model NO. | LW36-126 |
| Arc-extinguishing Medium | SF6 |
| Poles Number | 3 |
| Function | Circuit-Breaker Failure Protection, Overcurent Protection |
| Product Name | Hv Sulfur Hexafluoride Circuit Breakers |
| MOQ | 1PCS |
| Customize | Yes |
| Rated Frequency | 52Hz |
| Rated Short-Circuit Breaking Current | 40ka |
| Transport Package | Wood Box |
| Trademark | HaiRui |
| Speed | High-Speed Circuit Breaker |
| nstallation | Outdoor Installation |
| Type | Circuit Breaker |
| Cetification | ISO9001-2000 |
| Service | OEM/ODM |
| Warranty | 12 Months |
| Rated Voltage | 126kv |
| Rated Current | 3150A |
| Rated Short-Time Withstand Current/Durat | 40/3ka/S |
| Specification | Custom |
| Origin | Zhejiang,China |
Packaging & Delivery
| Package Size | 1.00cm*1.00cm*1.00cm |
| Package Gross Weight | 1.000kg |
Applications
- 126kV substations with long backup protection clearing times
- Busbar and transformer protection schemes needing high withstand margins
- Auto-reclose sequences where dead-time current exposure occurs
- Networks specified around 40kA/3s withstand requirements
- Protection retrofit projects replacing lower-withstand breakers
Frequently Asked Questions
What does the 40kA/3s withstand rating mean?
It means the breaker can carry a 40kA short-circuit current for up to 3 seconds without thermal or mechanical damage, remaining stable while protection relays complete their clearing sequence.
How does short-time withstand differ from breaking capacity?
Breaking capacity is the fault current the breaker interrupts when it opens; short-time withstand is the current it can safely carry while still closed. The LW36-126 is rated 40kA for both.
What precision features does the breaker offer?
It is a high-speed circuit breaker with SF6 arc extinguishing, providing fast and repeatable switching suitable for precisely coordinated protection schemes.
Where is the breaker installed?
It is an outdoor installation breaker in a 3-pole configuration, rated 126kV and 3150A, designed for open-air substations.
What are the ordering terms?
Minimum order is one piece, customization is supported, and OEM/ODM service is available. Each unit is packed in a wooden box with a 12-month warranty.
Get a Quote
As an ISO9001-certified manufacturer based in Zhejiang, China, HaiRui supplies the LW36-126 high voltage SF6 circuit breaker with flexible OEM/ODM service, customization support, and a 12-month warranty. Minimum order quantity is just one unit, and every breaker ships in a robust wooden export crate. Contact our engineering team with your ratings, altitude, and climate requirements for a detailed quotation and lead time.






FAQ
What does the 40kA/3s withstand rating mean?
It means the breaker can carry a 40kA short-circuit current for up to 3 seconds without thermal or mechanical damage, remaining stable while protection relays complete their clearing sequence.
How does short-time withstand differ from breaking capacity?
Breaking capacity is the fault current the breaker interrupts when it opens; short-time withstand is the current it can safely carry while still closed. The LW36-126 is rated 40kA for both.
What precision features does the breaker offer?
It is a high-speed circuit breaker with SF6 arc extinguishing, providing fast and repeatable switching suitable for precisely coordinated protection schemes.
Where is the breaker installed?
It is an outdoor installation breaker in a 3-pole configuration, rated 126kV and 3150A, designed for open-air substations.
What are the ordering terms?
Minimum order is one piece, customization is supported, and OEM/ODM service is available. Each unit is packed in a wooden box with a 12-month warranty.
Request Quote
Tell us your specifications, quantity, or application scenario and we will reply with a tailored quote.










