short circuits are deliberately created and utilized in the production and testing of medium-voltage switchgear. They are not an accident in this context, but a mandatory and destructive test used to verify the safety and performance of the equipment before it leaves the factory.
1. Short-Circuit Testing (The Core Method)
This is the most critical and destructive test for all MV switchgear and circuit breakers. The product must prove it can handle the extreme stresses of a real-world grid fault.
Key tests performed at national laboratories:
| Test | Purpose | Industry Standard |
|---|---|---|
| Rated Short-Circuit Breaking Current | To verify the circuit breaker can successfully "open" and interrupt the fault current under the most severe short-circuit conditions. | IEC 62271-100 |
| Short-Time / Peak Withstand Current | To verify the switchgear enclosure (e.g., KYN28) will not burst or deform under the massive electromagnetic forces of a short circuit. | IEC 62271-200 |
| Making Capacity Test | To prove the breaker can safely "close" onto an existing fault and withstand the resulting inrush shock. | GB/T 1984 |
| Dynamic & Thermal Stability Tests | To respectively verify the equipment's mechanical strength and thermal endurance during a short-circuit event. | GB/T 3906 |
2. Real-World Examples
In late 2025, Xi'an Jiaotong University and Pinggao Electric successfully developed the world's first 800kV/80kA high-voltage circuit breaker. Its success was validated by passing the 80kA short-circuit breaking test.
Recently, the Marine Medium-Voltage DC Circuit Breaker developed by the 704 Institute also succeeded after passing a 100kA short-circuit test.
3. Why Are These "Controlled Short Circuits" Necessary?
To Validate Limit Performance: Only in a professional short-circuit lab, using a high-power generator, can you simulate real fault currents to verify the device's breaking, thermal, and dynamic capabilities.
To Ensure Safety and Compliance: This is a mandatory certification requirement. A product cannot be sold for grid use without passing these short-circuit type tests.
4. Where Are These Tests Done?
Short-Circuit Laboratories: National authorized centers like the Xi'an High Voltage Apparatus Research Institute (XIHARI) or the China National Quality Supervision and Testing Center for Electrical Equipment.
Method: The equipment is connected to a high-power short-circuit generator. Using methods like "direct testing" or "synthetic testing," the device is subjected to repeated close/open operations under massive fault currents while data is monitored.
Products Description
KYN28-12 indoor armored metal-enclosed switch equipment (hereinafter referred to as KYN28-12 switchgear) is suitable for three-phase AC 50HZ, 7.2~17.5kV single busbar and single busbar sectionalized power system, with perfect "five-proof" function.
Our address
No. 1 East Gaoxin Avenue in the High-Tech Development Zone of Baoji City, Shaanxi Province, China
Phone Number
+86 180 9176 5658
xdtz03@westpowerelectric.com
