Application and Technical Analysis of Needle Flame Test Equipment in Fire Protection Detection of Electrical and Electronic Fields

Abstract:
Needle flame test equipment is a core fire safety detection device in the fields of electrical and electronic products, household appliances, lighting, and information technology equipment. By simulating the small flames generated by faults such as circuit short circuits and component overheating inside the equipment, it can accurately evaluate the flame resistance and fire safety of products and insulating materials under the scenario of ignition by small flames. Taking the LISUN ZY-3 Needle Flame Tester as the research object, this paper elaborates on the design principle, technical parameters, reference standards and typical applications of needle flame test equipment, analyzes its core value in product research and development, factory quality inspection and third-party certification, and provides technical reference for fire safety detection in relevant industries.

1. Introduction
With the development of electrical and electronic products, household appliances, lighting and information technology equipment towards miniaturization and integration, the internal circuit density of the equipment has increased, and the fire risk caused by small flames generated by faults such as circuit short circuits, component overheating and contact arcs has become increasingly prominent. Fire safety has become a core indicator for product market access. As a special detection device for simulating the ignition scenario of small flames, needle flame test equipment can restore the flame combustion state in actual equipment faults and provide scientific data in line with international and domestic standards for the evaluation of product flame resistance.

Needle flame test equipment applies a directional flame to the test sample through a standard needle burner, accurately detecting the ignition status, afterflame time and flame spread range of the test sample. Its test results directly determine whether the product meets the fire safety requirements. The ZY-3 Needle Flame Tester developed by LISUN for the detection needs of multiple industries has become a mainstream product of needle flame test equipment in the industry by virtue of its modular design, precise parameter control and wide adaptability, providing a reliable fire detection solution for electronic and electrical production enterprises, testing institutions and scientific research institutes.

2. Design Principle and Core Functions of Needle Flame Test Equipment
The core design goal of needle flame test equipment is to highly simulate the “small flames” generated by internal faults of electrical and electronic equipment. Such flames have the characteristics of concentrated energy, small combustion range and easy ignition of surrounding insulating materials, which are difficult to be accurately simulated by traditional fire detection equipment. Through optimizing the burner structure, precisely controlling flame parameters and integrating automatic test functions, needle flame test equipment realizes the whole-process simulation and data recording of the ignition process of small flames.

2.1 Core Test Principle
Needle flame test equipment adopts a needle burner of specified specifications (inner diameter 0.5mm, outer diameter 0.9mm), uses butane with a purity of ≥95% as the combustion gas, generates a needle flame with a height of 12mm±1mm, and applies the flame directionally to the designated part of the test sample at an inclined angle of 45°. During the test, the equipment automatically records the combustion time, sample ignition time and afterflame time, and simultaneously observes the flame spread and whether the dripping substances ignite the ignitable material below. Finally, it judges whether the flame resistance of the test sample is qualified in accordance with the standards.

2.2 Core Functional Characteristics
As a representative product in the industry, the LISUN ZY-3 needle flame test equipment integrates a number of functions such as precise temperature control, automatic timing, data recording and remote operation. Its core characteristics are reflected in three aspects: first, precise and controllable parameters, the time consumed for the flame temperature to rise from 100℃±2℃ to 700℃±3℃ is strictly controlled within 23.5s±1s, and the recording accuracy of afterflame time reaches ±0.1s, ensuring the standardization and comparability of test data; second, flexible test modes, supporting single/multiple continuous combustion, the combustion time can be customized within the range of 0~999.9s, adapting to the test needs of different products; third, safe and convenient operation, adopting the self-developed large LCD touch screen and remote control dual-mode operation, the operator can complete the test at a safe distance to avoid direct contact with the high-temperature combustion area.

3. Technical Parameters and Reference Standards of Needle Flame Test Equipment
The technical parameters of needle flame test equipment directly determine the test accuracy, and its design and production must strictly follow the relevant international and domestic standards to ensure that the test results are recognized by the global market. Taking the LISUN ZY-3/ZY-3S needle flame test equipment as a sample, this paper sorts out its core technical parameters and clarifies the corresponding reference standard system.

3.1 Core Technical Parameters
The LISUN ZY-3 needle flame test equipment is divided into two models: with cabinet (ZY-3) and without cabinet (ZY-3S), meeting the space requirements of different detection scenarios. Its core technical parameters are shown in Table 1.

Table 1 Core Technical Parameters of LISUN ZY-3/ZY-3S Needle Flame Test Equipment

Parameter Name	Technical Index
Burner angle	Adjustable, inclined at 45° during testing, vertical during flame height calibration
Combustion time	0~999.9s (±0.1s), 30s is recommended for routine use, customizable
Afterflame time recording	0~999.9s (±0.1s), automatic marking, supporting manual pause
Flame height	12mm±1mm
Combustion gas	Butane with purity ≥95% (electronic gas flowmeter optional)
Temperature measurement range	0~1000℃
Flame temperature rise requirement	From 100℃±2℃ to 700℃±3℃ within 23.5s±1s
Temperature measuring thermocouple	Φ0.5mm K-type
Number of combustion applications per test	Single/multiple continuous combustion can be set
Body material	High-temperature spray steel structure, high temperature resistant and corrosion resistant
Operation display	Self-developed large LCD touch screen + clear indicator light + remote control
Gross weight	ZY-3: 180kg; ZY-3S: 40kg

3.2 Reference Standards
The test process and result judgment of needle flame test equipment must strictly follow international and domestic standards. The LISUN ZY-3 needle flame test equipment is fully in line with the core standards for fire hazard testing of electrical and electronic products, and is also adapted to the special testing standards of various industries. Its core reference standards are shown in Table 2.

Table 2 Core Reference Standards for Needle Flame Test Equipment

Standard No.	Standard Name	Scope of Application
GB/T 5169.5-2020	Fire hazard testing for electrical and electronic products – Part 5: Test flames – Needle-flame test method – Apparatus, confirmatory test methods and guidance	General needle flame test for domestic electrical and electronic, household appliances and other products
IEC 60695-11-5:2016	Fire hazard testing – Part 11-5: Test flames – Needle-flame test method – Apparatus, confirmatory test arrangement and guidance	International general standard for needle flame test of electrical and electronic products
IEC 60695-2-2:2004	Fire hazard testing – Part 2-2: Test flames – Needle-flame test method – Apparatus, confirmation test methods and guidance	Old international needle flame test standard, replaced by IEC 60695-11-5:2016
IEC 62368-1:2023	Audio/video, information and communication technology equipment – Part 1: Safety requirements	Special needle flame test for information technology equipment

4. Typical Application Fields of Needle Flame Test Equipment
As a basic equipment for fire safety detection, needle flame test equipment is widely used in electrical and electronic, household appliances, lighting, information technology, automotive electronics and other fields. It can conduct flame resistance tests on complete products, core components and insulating materials, providing data support for product research and development, quality control and market access. The specific application of the LISUN ZY-3 needle flame test equipment in various fields is analyzed below.

4.1 Electrical and Electronic Equipment Industry
For low-voltage electrical appliances (relays, circuit breakers, terminal blocks), switches and sockets, cable insulation layers and other products, needle flame test equipment can simulate small flames generated by contact arcs and current overload to test the anti-ignition ability of the products. For example, conducting a needle flame test on the insulation parts of circuit breakers to verify whether they will continue to burn under the action of short-circuit flames and avoid the expansion of circuit faults caused by flame spread. This application scenario shall comply with GB/T 5169.5-2020, GB/T 2099.1-2021 and other standards.

4.2 Information Technology and Audio-visual Equipment Industry
Internal chips and power modules of equipment such as computers, printers, routers and mobile phone chargers are prone to generate small flames due to overheating. Needle flame test equipment can test their shells and insulation parts to evaluate the fire resistance after the failure of high-voltage components. For example, conducting a 30s standard combustion test on the shell of a mobile phone charger to ensure that it can self-extinguish under short-circuit flames and the dripping substances will not ignite surrounding materials, adapting to the UL 94:2024 flame retardant requirements.

4.3 Lighting Equipment Industry
Components of lighting products such as LED driver shells, lamp heat sinks and fluorescent ballasts are in direct contact with circuits or in a high-temperature environment for a long time. Needle flame test equipment can test their afterflame performance under fault small flames. For special lighting equipment such as stage lights and outdoor floodlights, the multiple continuous combustion mode can also be used to simulate the flame resistance under extreme fault scenarios, in line with GB 7000.1-2015 and IEC 60598-1:2020 standards.

4.4 Automotive Electronics and On-board Equipment Industry
In the fields of on-board electronics (navigators, on-board chargers) and new energy vehicles (charging piles, battery management systems), needle flame test equipment can test the flame resistance of wire harness insulation layers and insulation parts, simulate flames generated by charging overload and circuit faults, and ensure that the products meet the stringent fire standards of the automotive industry. For example, testing the insulation parts of charging piles to verify their stability under the action of 700℃ flame, in line with ISO 6722-1:2019 and GB/T 2408-2021 standards.

4.5 Material R&D and Detection Field
Needle flame test equipment can also be used for the R&D evaluation of insulating materials such as ABS/PC/PA engineering plastics, flame-retardant modified materials and epoxy glass cloth boards. By measuring the ignition and afterflame time of materials under small flames, it provides data support for the optimization of material formulas and promotes the R&D and application of materials with high flame retardancy.

5. Industrial Value and Development Trend of Needle Flame Test Equipment

5.1 Core Industrial Value
As the “first line of defense” for fire safety detection, the core value of needle flame test equipment is reflected in three aspects: first, ensuring product safety, eliminating products with unqualified flame resistance through accurate detection, and reducing fire accidents caused by equipment faults; second, facilitating market access, providing enterprises with test data in line with international and domestic standards, helping products pass CE, CCC and other certifications smoothly and enter the global market; third, driving technological upgrading, guiding enterprises to develop new materials and structures with high flame retardancy through testing the flame resistance of materials and components, and improving the overall fire safety level of the industry.

Taking the LISUN ZY-3 needle flame test equipment as an example, it has been applied in the market for more than 10 years and has become a standard equipment for electronic and electrical production enterprises and third-party testing institutions, providing fire detection services for hundreds of thousands of products and effectively reducing the fire risk in the electrical and electronic field.

5.2 Future Development Trend
With the continuous upgrading of fire safety standards in various industries, needle flame test equipment will develop towards intellectualization, integration and high precision: first, intellectualization, integrating the Internet of Things technology to realize cloud storage and remote analysis of test data and improve detection efficiency; second, integration, integrating needle flame test with glow wire, horizontal and vertical combustion and other test functions to realize one-stop detection of multiple items; third, high precision, optimizing the burner and temperature control system to further improve the control precision of flame parameters and adapt to more stringent test standards.

At the same time, in response to the fire detection needs of emerging fields such as new energy vehicles and artificial intelligence equipment, needle flame test equipment will develop customized test modes to simulate the ignition scenario of small flames under extreme environments, providing technical support for the fire safety of emerging industries.

6. Conclusion
As an indispensable fire safety detection device in the fields of electrical and electronic products, household appliances, lighting and information technology equipment, needle flame test equipment realizes the accurate evaluation of the flame resistance of products and insulating materials by simulating small flames generated by internal equipment faults. Relying on its modular design, precise parameter control, flexible test modes and wide standard adaptability, the LISUN ZY-3 Needle Flame Tester has become a representative product in the industry, providing reliable technical support for enterprise product research and development, factory quality inspection and third-party certification.

With fire safety receiving increasing attention, the technical level of needle flame test equipment directly affects the improvement of the industry’s fire safety threshold. In the future, with the integration of intelligent and integrated technologies, needle flame test equipment will further improve detection efficiency and precision, adapt to the detection needs of more emerging fields, and provide an important guarantee for promoting the development of fire safety in electrical and electronic industries and reducing the risk of fire accidents. At the same time, enterprises should attach importance to the application of needle flame test equipment, implement fire safety detection throughout the whole process of product research and development and production, and improve the fire safety performance of products from the source.

Tags：ZY-3