Glow wire ignition testing is a standardized method for evaluating the flammability of materials used in electrical and electronic equipment. This test simulates thermal stress caused by overheated or faulty components to assess whether a material will ignite, sustain combustion, or propagate flames. The procedure is governed by international standards such as IEC 60695-2-10, IEC 60695-2-11, IEC 60695-2-12, and IEC 60695-2-13, which define test conditions, apparatus requirements, and acceptance criteria.
Industries such as household appliances, automotive electronics, and telecommunications rely on glow wire testing to ensure compliance with safety regulations. The test is particularly critical for components like switches, sockets, and wiring systems, where material failure could lead to fire hazards.
The test involves heating a standardized Nichrome wire to a predetermined temperature (typically between 550°C and 960°C) and applying it to a test specimen for a specified duration (usually 30 seconds). The specimen’s reaction is observed and classified based on ignition time, flame duration, and production of flaming droplets.
Key parameters evaluated include:
These metrics determine whether a material meets safety thresholds for specific applications.
The LISUN ZRS-3H Glow-wire Test Apparatus is a precision instrument designed to conduct glow wire ignition tests in compliance with IEC 60695-2-10 to -2-13, GB/T 5169.10-13, and UL 746A standards. It is widely used in laboratories for product certification and quality control.
Manufacturers of circuit breakers, relays, and connectors use glow wire testing to verify that enclosures and insulating materials resist ignition under fault conditions. For example, thermoplastic housings in industrial control systems must withstand 750°C without sustained flaming.
Components such as power switches, thermostat housings, and wiring harnesses in appliances like microwaves and washing machines are tested to ensure they do not propagate flames when exposed to overheating.
With increasing electrification, automotive suppliers test battery management systems, charging ports, and infotainment components to meet ISO 8820 and LV 112-1 flammability requirements.
Materials in defibrillator casings, surgical tool handles, and imaging equipment must pass glow wire testing to minimize fire risks in oxygen-rich environments.
Glow wire testing is mandated by multiple regional and international standards:
Compliance ensures products meet safety benchmarks in target markets, reducing liability risks.
A recent study applied the LISUN ZRS-3H to test polyether ether ketone (PEEK) used in aircraft wiring conduits. At 850°C, PEEK exhibited no ignition after 30 seconds, validating its suitability for high-temperature environments.
Q1: What is the purpose of the tissue paper beneath the specimen?
A1: The tissue paper detects whether flaming droplets from the specimen ignite secondary materials, a critical factor in assessing fire propagation risks.
Q2: How often should the Nichrome wire be replaced?
A2: The wire should be inspected before each test and replaced if oxidation or deformation is observed, typically after 50–100 tests.
Q3: Can the ZRS-3H test non-planar specimens?
A3: Yes, custom fixtures can accommodate irregular shapes, provided the test surface contacts the glow wire uniformly.
Q4: What industries require glow wire testing?
A4: Key sectors include consumer electronics, automotive, medical devices, and industrial controls, where material flammability impacts safety compliance.
Q5: How does the ZRS-3H ensure temperature accuracy?
A5: A calibrated K-type thermocouple and PID controller maintain ±2°C precision, verified through periodic calibration checks.
By integrating rigorous testing protocols with advanced instrumentation like the LISUN ZRS-3H, manufacturers can mitigate fire hazards and ensure regulatory compliance across diverse applications.
