High-Current Current-Limiting Circuit Breaker/Short-Circuit Current Limiter(FCL)
Key attributes
| Brand | RW Energy |
| Model NO. | High-Current Current-Limiting Circuit Breaker/Short-Circuit Current Limiter(FCL) |
| Rated voltage | 20kV |
| Rated normal current | 1250A |
| Rated frequency | 50/60Hz |
| Series | DDXK |
Product descriptions from the supplier
Product Introduction
A core protection component for high-capacity power systems (35kV-220kV grids, industrial parks), the FCL responds in ≤10ms to short-circuit faults. It limits peak fault current to 15%-50% of the expected value before safe breaking, shielding generators/transformers. Supporting 630A-4000A current ratings, it fits AC/DC systems and integrates with switchgear for stable grid operation.
Feature
High-Speed Interruption: It operates and interrupts the short-circuit current at the front part of the first power frequency half-cycle of the short-circuit current—well before the current rises to its peak. The total interruption time is 2–5 ms, approximately 10–20 times faster than that of conventional circuit breakers.
Current-Limiting Interruption: It starts limiting the short-circuit current 1 ms after a short-circuit occurs, and finally restricts the short-circuit current to 15%–45% of the expected value.
High Interruption Capacity: The rated prospective short-circuit interruption current ranges from 63 kA to 200 kA, while the rated short-circuit interruption current of currently common circuit breakers usually only reaches 40.5 kA to 50 kA.
Built-in Rogowski Current Sensor: It features accurate measurement, fast response speed, and can be arranged in a phase-separated manner or integrated into switchgear cabinets.
High Reliability: One of the product’s competitive advantages is its outstanding reliability. Special design and craftsmanship ensure the product’s high reliability, which has been verified and well-received in on-site applications.
Main Parameters
No. |
Item |
Unit |
Technical Parameters |
|
1 |
Rated Current |
A |
630~6300 |
|
2 |
Rated Voltage |
kV |
7.2/12/20/40.5 |
|
3 |
Rated Frequency |
Hz |
50/60 |
|
4 |
Rated Prospective Short - Circuit Breaking Current |
kA |
63/80/120 |
|
5 |
Rated Insulation Level (Power Frequency / Lightning) |
7.2kV |
kV |
23/60 kV |
12kV |
42/75 kV |
|||
20kV |
50/125 kV |
|||
40.5kV |
95/185 kV |
|||
6 |
Breaking Time |
ms |
2~5ms |
|
7 |
Cut - off Current / Prospective Short - Circuit Current Peak Value |
% |
20~45 |
|
8 |
DC Resistance of Main Circuit |
μΩ |
＜40 |
|
9 |
Operating Current Setting Range |
kA |
6kA~60kA |
|
10 |
Rated Breaking Current of Fuse |
kA |
63/120 |
|
11 |
Rated Short - time Withstand Current of Main Circuit |
kA/s |
31.5/2 |
|
12 |
Rated Peak Withstand Current of Main Circuit |
kA |
80 |
|
Figure 4: Using DDXK1 as rapid short-circuit protection for generators and transformers
(a) Rapid short-circuit protection at the 10kV/35kV side outlet of transformers
(b) Rapid short-circuit protection at generator outlets
(c) Rapid short-circuit protection for power plant branch busbars
(d) Rapid short-circuit protection at grid-connected generator outlets
Less than 40 micro ohms (μ Ω), with extremely low conduction loss, does not affect the normal operating efficiency of the system.
The peak short-circuit current can be limited to 20% to 45% of the expected value, significantly reducing the dynamic and thermal stability burden on equipment such as transformers and busbars.
Covering 7.2kV, 12kV, 20kV, and 40.5kV, suitable for high-capacity distribution systems in 35kV to 220kV main grids and large industrial parks.
Related Products
-
General Protection Device
-
RWS-7000 Built - in bypass type motor soft starter
-
Line Sectionalizing Load Break Switch Controller
-
RWJS Partial Discharge Online Monitoring System for Ring Main Units
-
RWB-7000L Line Protection Measurement And Control Device
-
Feeder Terminal Unit
-
Advanced Recloser Controller
Related Knowledges
-
Faults and Handling of Single-phase Grounding in 10kV Distribution LinesCharacteristics and Detection Devices for Single-Phase Ground Faults1. Characteristics of Single-Phase Ground FaultsCentral Alarm Signals:The warning bell rings, and the indicator lamp labeled “Ground Fault on [X] kV Bus Section [Y]” illuminates. In systems with a Petersen coil (arc suppression coil) grounding the neutral point, the “Petersen Coil Operated” indicator also lights up.Insulation Monitoring Voltmeter Indications:The voltage of the faulted phase decreases (in01/30/2026 -
Neutral point grounding operation mode for 110kV～220kV power grid transformersThe arrangement of neutral point grounding operation modes for 110kV～220kV power grid transformers shall meet the insulation withstand requirements of transformer neutral points, and shall also strive to keep the zero-sequence impedance of substations basically unchanged, while ensuring that the zero-sequence comprehensive impedance at any short-circuit point in the system does not exceed three times the positive-sequence comprehensive impedance.For 220kV and 110kV transformers in new constructi01/29/2026 -
Why Do Substations Use Stones, Gravel, Pebbles, and Crushed Rock?Why Do Substations Use Stones, Gravel, Pebbles, and Crushed Rock?In substations, equipment such as power and distribution transformers, transmission lines, voltage transformers, current transformers, and disconnect switches all require grounding. Beyond grounding, we will now explore in depth why gravel and crushed stone are commonly used in substations. Though they appear ordinary, these stones play a critical safety and functional role.In substation grounding design—especially when multiple gr01/29/2026 -
Why Must a Transformer Core Be Grounded at Only One Point? Isn't Multi-Point Grounding More Reliable?Why Does the Transformer Core Need to Be Grounded?During operation, the transformer core, along with the metal structures, parts, and components that fix the core and windings, are all situated in a strong electric field. Under the influence of this electric field, they acquire a relatively high potential with respect to ground. If the core is not grounded, a potential difference will exist between the core and the grounded clamping structures and tank, which may lead to intermittent discharge.I01/29/2026 -
Understanding Transformer Neutral GroundingI. What is a Neutral Point?In transformers and generators, the neutral point is a specific point in the winding where the absolute voltage between this point and each external terminal is equal. In the diagram below, pointOrepresents the neutral point.II. Why Does the Neutral Point Need Grounding?The electrical connection method between the neutral point and earth in a three-phase AC power system is called theneutral grounding method. This grounding method directly affects:The safety, reliabilit01/29/2026 -
What’s the Difference Between Rectifier Transformers and Power Transformers?What is a Rectifier Transformer?"Power conversion" is a general term encompassing rectification, inversion, and frequency conversion, with rectification being the most widely used among them. Rectifier equipment converts input AC power into DC output through rectification and filtering. A rectifier transformer serves as the power supply transformer for such rectifier equipment. In industrial applications, most DC power supplies are obtained by combining a rectifier transformer with rectifier equ01/29/2026
Related Solutions
-
Distribution automation systems solutionsWhat are the difficulties in overhead line operation and maintenance?Difficulty one:Overhead lines of distribution network have wide coverage,complicatedterrain,many radiation branches and distributed power supply,resultingin "many line faults and difficulty in fault troubleshooting".Difficulty Two:Manual troubleshooting is time-consuming and laborious.Meanwhile,therunning current,voltage and switching state of the line cannot be graspedin real time,because of the lack of intelligent technical m04/22/2025 -
RW8000 DMS Distribution Management System SolutionsOverviewNowadays, the development trend of power grid is intellectualization. As an important part of power grid, the power distribution system is very close to the customers and it has to run properly. The distribution management system (DMS）played an important role in it.Introduction:RW8000 power distribution management system (DMS) is designed for the smart grids. It is based on real-time application, centered on distribution network operation and management, focusing on the business process09/07/2023 -
High-Precision Electrical Parameter Monitoring System Solution1.IntroductionWith the increasingly stringent requirements for power supply quality in high-end facilities such as precision manufacturing, medical diagnosis, and data centers, traditional power monitoring systems, due to their low sampling accuracy and weak data analysis capabilities, can no longer meet the demand for deep insight and precise management of power quality. In response, we are introducing a new generation High-Precision Electrical Parameter Monitoring System. With millisecond-l09/28/2025
