What is fuse arc extinguishing?

Comprehensive Analysis of Fuse Arc Extinguishing: Principles, Technologies, and Applications
1、 Definition and core principle of fuse arc extinguishing
Arc extinguishing refers to the rapid extinguishing of the arc generated by a fuse through physical or chemical means during the melting process, ensuring the complete disconnection of the circuit and preventing equipment damage or fire risks. The core principles include:
Arc generation mechanism
When a fuse is blown, the molten metal (such as copper or silver alloy) melts due to current overload, producing high-temperature ionized gas (arc) with a temperature of over 3000 ℃.
The arc energy is directly proportional to the circuit voltage and current. For example, in an AC250V circuit, a regular fuse may cause continuous arcing.
The essence of arc extinguishing
Reduce arc temperature: Quickly cool the arc through heat absorbing materials such as quartz sand.
Increase resistance: Use arc extinguishing agents (such as chloride salts) to neutralize ionized ions and increase arc resistance.
Split arc: Divide a long arc into multiple short arcs to reduce energy density.
2、 Key technologies and materials for fuse arc extinguishing
1. Arc extinguishing material
Quartz sand (silica)
The mainstream arc extinguishing agent achieves cooling by absorbing heat and splitting the arc. The specific surface area of nanoscale quartz sand reaches 300m ²/g, and the heat absorption efficiency is 2.3 times higher than that of micrometer sized materials.
Case: 5TR explosion-proof fuse is filled with quartz sand, and the arc duration is controlled within 0.01 seconds.
Chloride salt
Decompose into chloride ions, neutralize the positive ions generated by ionization, and reduce plasma concentration. After adding chloride salt, the arc resistance increased by 40% and the arc ignition time was shortened.
boron nitride
Used in humid environments (such as offshore platforms) to enhance insulation performance, the success rate of arc extinguishing has increased from 92% to 99%.
2. Structural design
Narrow neck segmentation
Splitting the melt into multiple narrow neck segments (such as the 12 independent arcs of 5TE type fuses) reduces the energy of a single arc by 70%.
interrupter
High voltage fuses (such as 10kV explosion-proof fuses) adopt a multi-layer arc extinguishing plate structure, filled with composite arc extinguishing agents, and can extinguish a 15kA arc within 5ms.
Magnetic field assistance
Using magnetic fields to drive arc motion and accelerate cooling (such as the carbon nanotube enhanced arc extinguishing material developed in the laboratory).
3. Dynamic response optimization
Miniature fuse: Under 100A impulse current, the arc extinguishing time is only 1.2ms, avoiding overvoltage damage to adjacent components.
Environmental temperature compensation: Adjust the arc extinguishing agent formula in low-temperature environments (such as increasing the proportion of chloride salts) to maintain heat absorption efficiency.
3、 Standards and Testing Requirements
1. UL 248 standard (North America)
Overload test: Apply an overload current of 135% -200% of the rated current to verify whether the melting time meets the standard.
Breaking ability test: Simulate short-circuit faults and evaluate the current cutting ability of fuses at specific voltages (such as 1500V DC).
Case: 5TR explosion-proof fuse passed UL 248 test, with arc duration ≤ 0.01 seconds.
2. IEC 60269 standard (international)
Breaking ability test: The photovoltaic fuse needs to cut off the arc within 5ms at 1500V DC.
Temperature rise test: The surface temperature under rated current is ≤ 80 ℃ to ensure thermal stability.
Latest requirement: IEC 60269-6:2021 adds testing for high voltage breaking capacity and photovoltaic inverter return current.
3. Special application standards
In the automotive field, ISO 8820 requires fuses to respond quickly under extreme working conditions to prevent system level failures.
Semiconductor protection: IEC 60269-4 specifies fast response (<1ms) and low power consumption.
4、 Special Scenarios and Application Cases
1. Car fuses
High Voltage Direct Current (HVDC) Application: Using fuses with added boron nitride to adapt to temperature rises of -40 ℃ to 85 ℃, the success rate of arc extinguishing is increased to 99%.
Case: A certain electric vehicle fuse has passed the JASO-D622 standard, with a withstand voltage of 450V DC and a breaking capacity of 50kA.
2. Photovoltaic system
DC arc extinguishing: The fuse needs to withstand 1500V DC, filled with composite arc extinguishing agent, and cut off the arc within 5ms.
Case: A certain photovoltaic power station uses IEC 60269-6 certified fuses to prevent fires caused by electric arcs.
3. Intelligent arc extinguisher
IoT integration: Combining power semiconductor and NB IoT technology to achieve microsecond level line disconnection (such as within 150 μ s) and real-time monitoring of power consumption data.
Case: Nanjing Golden Eagle World installed an intelligent arc extinguisher to cut off the circuit within 150 μ s in case of a short circuit, avoiding electrical fires.
4. Offshore platforms
Customized arc extinguishing solution: Adding 0.5% boron nitride fuse to enhance insulation performance in humid environments, increasing the success rate of arc extinguishing from 92% to 99%.
5、 Summary and Prospect
Fuse arc extinguishing is the core technology of circuit protection, which ensures the rapid suppression of arcs through the comprehensive application of materials (quartz sand, chloride salt), structures (narrow neck segmentation, arc extinguishing chamber), and standards (UL/IEC). Future development directions include:
Nanocomposite arc extinguishing agent: enhances breaking capacity (such as 80kA) and reduces volume.
Magnetic field assisted arc extinguishing: further shortening the arc ignition time.
Environmentally friendly materials: replace heavy metals such as lead and mercury, and comply with RoHS/REACH standards.
Through continuous innovation in arc extinguishing technology, fuses will play a more critical role in ensuring safety in fields such as new energy and automotive electronics.