In daily life and industrial production, electrical devices such as televisions, washing machines, and charging piles have long become indispensable. However, when these devices operate, internal components may develop high temperatures due to faults like overload or short circuit. Once the surrounding insulating materials or enclosures catch fire, they can easily trigger fire accidents. To mitigate such risks, engineers developed the Glow Wire Test – it acts like a precise "fire-prevention sentinel." By simulating the glowing effect of high-temperature components inside electrical devices, it tests the flame resistance of materials and builds the first line of defense for electrical safety.

I. What is the Glow Wire Test?

The Glow Wire Test is a specified electrical safety test item in standard systems such as the International Electrotechnical Commission (IEC), China National Standards (GB), Underwriters Laboratories (UL), Deutsches Institut für Normung (DIN), and Verband der Elektrotechnik, Elektronik und Informationstechnik (VDE). Its core is to simulate the thermal impact of "glowing components" (e.g., overloaded resistance wires, short-circuited terminals) inside electrical devices on surrounding solid insulating materials or flammable parts.

When an electrical device malfunctions, some components may suddenly reach temperatures between 800℃ and 1200℃ – high enough to ignite nearby polymer materials like plastics and rubbers. The Glow Wire Test uses a standardized "glow wire" (made of high-temperature-resistant nichrome) to touch the test sample at a specified temperature. And observing whether the material ignites, the duration of the flame, and whether drippings ignite the underlay below. Through these observations, to determine if the material can resist short-term high-temperature impacts.

The core objective of the test is not to "destroy the material," but to screen materials that meet safety requirements through scientific testing. It must ensure two things: first, the material remains unaffected by mild high temperatures during normal use; second, the material delays or prevents the spread of combustion as much as possible under fault-induced high temperatures, buying valuable time for personnel evacuation and equipment power-off.

II. Test Principle: Restoring High-Temperature Risks with Standardized Methods

The principle of the Glow Wire Test may seem simple, but it involves strict standardized design to ensure the accuracy and comparability of test results. The test equipment mainly consists of three parts:

1. Glow Wire Loop: The core is a 4mm-diameter nichrome wire (80% Ni/20% Cr), with its top processed into a hemispherical shape to ensure a constant contact area with the test sample. The wire is heated by a dedicated heating device, and its temperature can be precisely controlled (ranging from 550℃ to 960℃) according to test standards.

2. Sample Fixing Device: It fixes the test sample to ensure the contact pressure (0.95N ± 0.1N) and contact time (generally 30s ± 1s) between the sample and the glow wire loop meet standard requirements. This avoids test deviations caused by inconsistent contact conditions.

3. Observation and Recording System: It includes timing devices (to record flame duration and glowing duration), an underlay (usually 0.5mm-thick absorbent cotton, used to detect if drippings ignite), and a temperature monitor. These components capture key data in real time during the test.

During the test, operators first heat the glow wire loop to the temperature specified by the standard and keep it stable for more than 10 seconds. Then, they press the glow wire loop against the sample surface with constant pressure. After reaching the specified contact time, they remove the glow wire loop and immediately check two things: whether the sample "ignites" (produces flame or glow) and if the flame duration exceeds the standard limit (for example, IEC 60695-2-11 stipulates that the flame duration of non-flame-retardant materials must be ≤ 30 seconds). They also check if the absorbent cotton is ignited by drippings. Together, these data form the basis for judging the material’s flame resistance.

III. Standard System: A Universal "Safety Benchmark" Worldwide

The Glow Wire Test is not an isolated testing method, it relies on a sound system of international and domestic standards to ensure consistent test results across different laboratories and enterprises. Currently, the world’s mainstream standards fall into two categories:

International Standards (IEC System): Centered on the IEC 60695-2-10 series. Among them, IEC 60695-2-10 specifies the general method for the Glow Wire Test; IEC 60695-2-11 focuses on "Glow Wire Ignition Temperature Test" (to determine the minimum temperature at which a material ignites); IEC 60695-2-12 focuses on "Glow Wire Flammability Index Test" (to evaluate a material’s ability to sustain combustion). These standards cover all scenarios from basic testing to specialized assessment.

Chinese Standards (GB System): China has developed the GB/T 5169 series of standards with reference to IEC standards. Among them, GB/T 5169.10 corresponds to the general test method; GB/T 5169.11 and GB/T 5169.12 are equivalent to IEC’s ignition temperature and flammability index test standards, respectively. This design ensures that domestic product testing aligns with international practices – it not only meets domestic market access requirements but also provides compliance support for exported products.

Different industries and products have significantly different temperature requirements for the Glow Wire Test. For example, the enclosure materials of household appliances usually need to pass the 750℃ Glow Wire Test; while the insulating components inside charging piles, which are close to high-current elements, may need to meet the strict 960℃ requirement. These specific indicators must be determined based on the safety standards corresponding to the products (e.g., IEC 60335-1, IEC 60320-1, IEC 60884-1).

IV. Conclusion: A Small Test Bears Great Responsibility for Safety

The Glow Wire Test may seem like a "niche" professional test, but it is closely related to everyone’s electrical safety. By scientifically simulating risks and strictly judging performance, it eliminates fire hazards of electrical devices during the R&D and production stages.

To meet the demand for Glow Wire Testing, PEG has launched the Glow Wire Test Apparatus. Users can introduce this apparatus into their own laboratories – this not only significantly reduces testing costs but also saves time spent on sending samples back and forth for testing, accelerating R&D and production cycles. For inquiries about the price of the Glow Wire Test Apparatus, please contact our team to get an official quotation.