For the household appliance industry, safety has always been a concern. Due to misoperation, the electrical wiring system may cause current overload or short circuit, which may cause the burning of plastic materials. Therefore, the industry has formulated various fire protection requirements to evaluate and determine the flammability level of materials used in electrical appliances. Glow wire testing is one of the relevant fire protection requirements adopted by the household appliance industry today.
The International Electrotechnical Commission (IEC) developed the hot wire test method in 2001, because the original test method can not cover all ignition sources. Specifically, the hot wire test is mainly used to simulate the heating effect that may occur when the electrical equipment fails due to the overload or overheating of the connected components.
IEC 60335-1 specifies the standard of hot wire for household appliances. The latest version is edition 5.0 2010-05. However, the specific hot wire test method is mainly reflected in the IEC 60695-2 series of specifications.
The glow wire test is achieved by heating the element to a predetermined temperature. The heating element is called glow wire. Figure 3 is an example of a heating element used in the glow wire test. The sample to be tested is fixed in place, and the cotton paper is directly placed under the sample. After reaching the predetermined temperature, press the hot wire on the sample with a force of 1n for 30s. If combustion occurs within 30s, record the duration, flame height, and whether the material drops ignite the cotton paper.