Needle Flame Burner: Application and Technical Analysis in Fire Safety Testing of Electrical and Electronic Equipment

Abstract
With the development of miniaturization and high-powerization of products in fields such as electrical and electronic equipment, home appliances, and lighting, the fire risk caused by “small flames” from circuit short circuits and component overheating has become increasingly prominent. Fire safety testing has thus become a core link in product research and development, factory quality inspection, and certification. As a dedicated device for simulating small flame ignition scenarios, the needle flame burner’s testing accuracy and operational convenience directly determine the reliability of fire resistance performance evaluation. This paper takes the LISUN ZY-3 Needle Flame Burner as the research object, systematically expounds on its modular design advantages, deeply analyzes the technical principles of core functions such as precise temperature control, automatic timing, and data recording, and verifies the device’s adaptability in multi-industry fire safety testing by combining its international standard-compliant flame parameter control capabilities and dual-mode operation design. Through the analysis of typical application scenarios and performance parameter comparison, the technical value of the LISUN ZY-3 Needle Flame Burner in ensuring product fire safety and meeting market access requirements is highlighted, providing a professional testing solution reference for electrical and electronic product manufacturers, testing institutions, and scientific research institutes.

1. Introduction
During the operation of electrical and electronic equipment, faults such as component aging, circuit overload, or short circuits can easily generate “small flames” with temperatures exceeding 700°C. Although these flames are small in size, they are concentrated in energy and can easily ignite the internal insulating materials or casings of the equipment, thereby triggering large-scale fires. To prevent such risks, institutions such as the International Electrotechnical Commission (IEC) and the National Standardization Administration have successively issued needle flame test standards (e.g., IEC 60695-11-5:2016, GB/T 5169.5-2020), which clearly require simulating small flame scenarios to test the fire resistance and flame persistence characteristics of products and materials.

Traditional needle flame testing equipment has problems such as scattered functions, low parameter control accuracy, and complex operation processes. For example, manual adjustment of flame height easily leads to errors, and manual timing makes it difficult to accurately record flame persistence time, which cannot meet the requirements of high-standard testing. The ZY-3 Needle Flame Burner developed by LISUN adopts a modular integrated design, integrating functions such as precise temperature control, automatic timing, and data recording. At the same time, it optimizes the testing process through a dual-operation mode of touchscreen and remote control. It not only strictly complies with international and domestic standards but also can adapt to the testing needs of samples of different sizes. It has been widely used in fields such as electrical and electronics, lighting, and automotive electronics, becoming a key device for fire safety testing. This paper will comprehensively analyze the technical advantages and industrial value of the LISUN ZY-3 Needle Flame Burner from four dimensions: equipment technical architecture, core function principles, application scenarios, and performance verification.

2. Technical Architecture and Core Function Principles of LISUN ZY-3 Needle Flame Burner
2.1 Modular Design Architecture
The modular design of the LISUN ZY-3 Needle Flame Burner is the basis for its function integration and flexible adaptation. It is divided into five core modules as a whole. Each module operates independently and collaborates interactively to ensure the accuracy and stability of the testing process:
• Combustion System Module: It includes a standard needle-shaped burner (inner diameter 0.5mm), a gas supply unit, and a flame adjustment component. The angle of the burner can be flexibly adjusted (tilted at 45° during testing and vertical during flame height calibration). The combustion gas uses butane with a purity of ≥95%, and an optional electronic gas flowmeter is available to precisely control the gas flow rate to stabilize the flame shape.
• Temperature Control Module: It integrates a Φ0.5mm K-type thermocouple and a high-precision temperature acquisition chip. The temperature measurement range covers 0~1000°C, which can real-time monitor the flame temperature rise process and strictly ensure the standard requirement of “taking 23.5s±1s to rise from 100°C±2°C to 700°C±3°C”, avoiding the impact of temperature deviation on test results.
• Timing and Data Recording Module: It has a built-in high-precision timing chip. The combustion time (0~999.9s, ±0.1s) and flame persistence time (0~999.9s, ±0.1s) can be automatically recorded. It supports single or multiple consecutive combustion settings. Test data is stored in the device memory in real-time and can be exported to a computer via USB for secondary analysis.
• Operation and Safety Module: It is equipped with a self-developed large LCD touchscreen and a wireless remote control, supporting functions such as parameter setting, test start/pause, and data viewing. At the same time, it integrates overheating protection, gas leakage alarm, and emergency stop button. When the device temperature exceeds the threshold or the gas concentration is abnormal, it automatically cuts off the gas source and alarms.
• Sample Fixing Module: It provides an adjustable fixture to adapt to samples of different sizes (such as small relay casings, large cable insulation layers, film materials, etc.). The height and horizontal position of the fixture can be fine-tuned to ensure that the combustion distance between the burner and the sample meets the standard requirements (usually 5mm±0.5mm).

2.2 Technical Principles of Core Functions
2.2.1 Precise Temperature Control Technology
Flame temperature is a core parameter of the needle flame test, which directly affects the determination of the material ignition threshold. The LISUN ZY-3 Needle Flame Burner achieves precise temperature control through the collaboration of “real-time thermocouple acquisition + PID algorithm dynamic adjustment”:
• Temperature Acquisition: The tip of the K-type thermocouple is closely attached to the core area of the flame, collecting temperature data 10 times per second and converting the analog signal into a digital signal for transmission to the main control chip.
• PID Adjustment: Based on the PID algorithm, the main control chip compares the real-time temperature with the standard temperature curve (100°C→700°C, 23.5s±1s), and automatically adjusts the butane gas flow rate and the burner damper opening. If the temperature rises too slowly, the gas flow rate is increased; if the temperature overshoots, the flow rate is reduced to ensure that the flame temperature strictly complies with the requirements of GB/T 5169.5-2020 and IEC 60695-11-5:2016 standards.

2.2.2 Automatic Timing and Data Recording
Traditional manual timing is prone to errors (more than ±0.5s) due to personnel reaction delays. The LISUN ZY-3 achieves millisecond-level timing accuracy through the collaboration of hardware and software:
• Combustion Timing: After the test starts, the device automatically records the time when the burner contacts the sample. When the set combustion time (such as the conventional 30s) is reached, the burner automatically resets, with a timing accuracy of ±0.1s.
• Flame Persistence Timing: After the sample is separated from the flame, the device monitors whether the sample continues to burn through an optical sensor. If a flame is detected, it automatically starts the flame persistence timing; when the flame is extinguished, it automatically stops the timing and marks data such as “ignition status”, “flame persistence time”, and “combustion spread situation”, avoiding subjective errors in manual observation.
• Data Storage: It supports the storage of more than 5,000 groups of test data. Each group of data includes test time, sample information, combustion time, flame persistence time, temperature curve, etc., which can be exported in Excel format to facilitate the generation of test reports and data traceability.

2.2.3 Dual-Mode Operation and Safety Assurance
To simplify the operation process and reduce the risk of high-temperature burns, the LISUN ZY-3 adopts a dual-operation mode of “touchscreen + remote control”:
• Touchscreen Operation: The 5-inch LCD touchscreen displays real-time temperature, timing data, flame status, and other information. It supports one-click parameter setting (such as 30s combustion time and 12mm flame height). The interface is intuitive and easy to understand, allowing new operators to get started quickly.
• Remote Control Operation: It is equipped with a wireless remote control, allowing testers to start/pause the test from a distance of 3 meters, avoiding close contact with the high-temperature burner (flame temperature exceeds 700°C). At the same time, the device body is made of high-temperature spray-coated steel structure, which is high-temperature resistant and corrosion-resistant, further ensuring operational safety.

3. Parameter Specifications and Industrial Application Scenarios of LISUN ZY-3 Needle Flame Burner
3.1 Core Parameter Specifications and Model Comparison
The LISUN ZY-3 Needle Flame Burner includes two models: ZY-3 (with cabinet) and ZY-3S (without cabinet). The core parameters strictly comply with international standards and can be selected according to different testing environments and sample requirements. The following table shows the parameter comparison and standard compliance of the two models:

3.2 Analysis of Typical Industrial Application Scenarios
With its modular design and precise testing capabilities, the LISUN ZY-3 Needle Flame Burner has been widely used in fields such as electrical and electronics, information technology equipment, lighting, and automotive electronics. The following are core application scenario cases:

3.2.1 Electrical and Electronic Industry: Fire Testing of Low-Voltage Electrical Appliances
If the casings and insulating parts of low-voltage electrical appliances (such as relays, contactors, and circuit breakers) are ignited by small flames, it may lead to expanded circuit short-circuit faults. A low-voltage electrical appliance manufacturer used the LISUN ZY-3 Needle Flame Burner to test the relay casing (ABS flame-retardant material):
• Test Setup: Combustion time of 30s, burner tilted at 45°, combustion point at the weak part of the casing (thickness 1.5mm).
• Test Result: The sample did not ignite during combustion and had no flame persistence after being separated from the flame, complying with the requirements of GB/T 5169.5-2020.
• Application Value: Unqualified batches were screened out through batch testing (a certain batch of casings ignited at 25s of combustion with a flame persistence time of 8s), preventing them from entering the market and causing safety hazards. At the same time, it provided data support for material formula optimization (increasing the flame retardant content of ABS material from 15% to 20% to solve the ignition problem).

3.2.2 Lighting Equipment Industry: Fire Testing of LED Drivers and Luminaires
Due to the long-term high-temperature operation of LED luminaires, the driver casings and lamp holder insulating materials are prone to becoming fire hazards. A lighting enterprise used the LISUN ZY-3 Needle Flame Burner to test the LED driver casing (PC material):
• Test Basis: GB 7000.1-2015 “Luminaires – Part 1: General Requirements and Tests”.
• Test Process: Simulate small flames generated by overheating of internal components of the driver, conduct 30s combustion on the driver casing, and monitor whether ignition and combustion spread occur.
• Key Result: Qualified casings had no open flame after combustion, only slight surface carbonization; unqualified casings (recycled PC material) ignited at 18s of combustion with a flame persistence time of 12s, and the flame spread to internal circuits. This test effectively intercepted unqualified products and ensured the safety of luminaire use.

3.2.3 Automotive Electronics Industry: Testing of New Energy Vehicle Charging Piles
Due to the large charging current of new energy vehicle charging piles, if the insulating parts are ignited by small flames, it may cause battery fire accidents. A third-party testing institution used the LISUN ZY-3 Needle Flame Burner to test the insulating parts (epoxy glass cloth board) of the charging pile:
• Test Standards: GB/T 2408-2021 “Plastics – Determination of Burning Behavior – Horizontal and Vertical Methods”, IEC 60695-11-5:2016.
• Test Focus: Monitor the ignition time, flame persistence time of the insulating parts under 700°C flame, and whether drippings are generated (drippings may ignite combustibles below).
• Test Conclusion: Qualified insulating parts had no ignition, no drippings, and a flame persistence time of 0s, complying with the fire protection requirements of charging piles; a submitted sample ignited at 22s of combustion with a flame persistence time of 9s and generated drippings, which was determined to be unqualified, helping enterprises avoid product certification risks.

3.2.4 Material R&D Field: Evaluation of Flame Retardant Performance of Engineering Plastics
Scientific research institutes often use the LISUN ZY-3 Needle Flame Burner to evaluate the performance of new flame-retardant materials. A material research institute tested modified PA66 material (added with halogen-free flame retardant):
• Test Purpose: Verify the fire resistance of the material under small flames and provide a basis for the selection of electrical and electronic casing materials.
• Test Variables: Change the flame retardant addition amount (10%, 15%, 20%) and compare the ignition time and flame persistence time under different addition amounts.
• Research Result: When the flame retardant addition amount was 20%, the material had no ignition; when it was 15%, the ignition time was 15s and the flame persistence time was 3s; when it was 10%, the ignition time was 8s and the flame persistence time was 15s. Finally, 15% was determined as the optimal addition amount (balancing fire resistance and cost).

4. Performance Verification and Standard Compliance of LISUN ZY-3 Needle Flame Burner
4.1 Performance Verification Data
To verify the testing accuracy of the LISUN ZY-3 Needle Flame Burner, a standard sample (phenolic plastic plate specified in GB/T 5169.5-2020) was selected for repeated testing. The results are shown in the following table:

It can be seen from the data that the key indicators of the LISUN ZY-3 Needle Flame Burner, such as flame height, temperature rise time, and timing accuracy, all meet the standard requirements, and the ignition determination accuracy reaches 100% with good test repeatability, which can ensure the reliability of test results.

4.2 Standard Compliance
The LISUN ZY-3 Needle Flame Burner strictly adheres to a number of international and domestic authoritative standards to ensure the global recognition of test results:
• Core Test Method Standards: GB/T 5169.5-2020 “Fire Hazard Testing for Electrical and Electronic Products – Part 5: Test Flames – Needle Flame Test Method”, IEC 60695-11-5:2016 “Fire • Hazard Testing – Part 11-5: Test Flames – Needle-Flame Test Method”.
• Product-Specific Standards: GB 7000.1-2015 “Luminaires – Part 1: General Requirements and Tests”, GB/T 4943.1-2022 “Information Technology Equipment – Safety – Part 1: General Requirements”, GB/T 2408-2021 “Plastics – Determination of Burning Behavior”, IEC 62368-1:2023 “Audio/video, information and communication technology equipment – Part 1: Safety requirements”.
• Industry-Specific Standards: ISO 6722-1:2019 “Road Vehicles – Cables, wires and harnesses – Part 1: General requirements and test methods” (automotive wire harness testing), UL 94:2024 “Standard for Tests for Flammability of Plastic Materials for Parts in Devices and Appliances” (plastic flame retardant testing).

5. Conclusions 
The LISUN ZY-3 Needle Flame Burner integrates core functions such as precise temperature control, automatic timing, and data recording through a modular design, solving the pain points of traditional equipment such as “low parameter accuracy, complex operation, and high safety risks”. Its strict standard compliance and flexible adaptability make it a core device for fire safety testing in fields such as electrical and electronics, lighting, and automotive electronics. From factory quality inspection of enterprises to third-party certification and material research and development in scientific research institutes, this device can provide reliable test data, helping products meet market access requirements and reduce fire risks.