Glow wire test device> is to simulate insulating materials or other solid combustible materials that are easy to spread flames inside the equipment parts may ignite due to glowing wires or elements. Under certain conditions, such as fault current flowing through the wire, component overload and poor contact, some components will reach a certain temperature and cause the nearby parts to ignite.
The working principle of the glow wire test device: heat the nickel-chromium wire (U-shaped glow wire head) with a specified material of Φ4 mm to the specified temperature (300 ℃ ~ 1000 ℃) with a large current, and then press the specified pressure (1.0 N) Burn the test product horizontally for 30s. Whether the test product and the bedding are ignited or lasted to determine the fire hazard of the finished electrical and electronic equipment; after the test is completed, record the burning time, igniting time (Ti), and flame extinguishing time ( Te), flammability index (GWFI).
Glow wire head: measure the temperature of the glow wire with an armored filament thermocouple with a nominal diameter of 0.5mm. The wire is nickel-chromium and nickel-aluminum (K-type) wire, suitable for temperatures up to 960 Continuous operation under the condition of ℃, their welding points are located in the armored sheath, the thermocouple used to measure the temperature of the glow wire, the metal of the armored sheath can withstand the temperature of at least 1050 ℃.
The glow wire test is a kind of flame retardant performance test used in the electrical and electronic product industry to determine the electronic products, in order to test the stability of electronic and electrical products when they are working. Glow wire test is a physical experiment, the purpose is to test the stability of electronic and electrical products when they are working. The glow wire itself is actually a resistance wire ring with a fixed specification. During the test, it must be heated to a specified temperature with electricity, so that the top of the glow wire contacts the sample for a standard time, and then observe and measure its state. The test range depends on the specific test procedure.
Glow wire test method:>
IEC 60335-1 specifies the glow wire standard for household appliances, the latest version is its Edition 5.0 2010-05. However, the specific glow wire test method is mainly reflected in the IEC 60695-2-10 and other specifications.
The glow wire test is achieved by heating the element to a predetermined temperature. The heating element is called a glow wire. Figure 3 is an example of a heating element used in the glow wire test. The sample to be tested is held in place with a tissue placed directly under the sample. After reaching the predetermined temperature, press the glow 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 dripping ignites the tissue paper.
Glow wire testing can be performed on both end product and raw material samples. The terminology that defines compliance is slightly different in the two cases.
GWT is short for Glow Wire Test (IEC 60695-2-11). GWT is used when performing glow wire tests on end products. The result of the test is then pass or fail at the given temperature. If the sample does not ignite or extinguishes automatically within 30 seconds after removing the heating element, if dripping occurs and the dripping does not ignite the tissue paper, it is passed.
GWFI stands for Glow Wire Flammability Index (IEC 60695-2-12). It is a property related to the raw material used in the final product. This property is determined by performing a glow-wire test on a sample of the raw material of a given thickness. GWFI is the highest temperature at which the glow wire does not ignite or automatically extinguishes within 30 seconds after the heating element is removed.
GWIT stands for Glow Wire Ignition Temperature (IEC 60695-2-13). It is a property related to the raw material used in the final product. This property is determined by performing a glow-wire test on a sample of the raw material of a given thickness. GWIT is the lowest temperature at which the material ignites and burns for more than 5 seconds when the heating element is in contact with the sample.
Experimental requirements for the ignition temperature test of insulating materials:>
In addition to the provisions of Chapter 8 of IOS 5169.10-2006, unless otherwise specified, the test sample The installation shall be such that the tip of the glow wire is applied to that part of the surface of the test specimen which may be subjected to thermal stress in normal use. The glow wire should be kept as horizontal as possible. When more than one point is tested on the same test sample, care should be taken that the deterioration caused by previous tests cannot affect the results of subsequent tests.
When the area where the equipment is subjected to thermal stress during normal use is not specified in detail, the top of the glow wire should be applied at the thinnest part of the test sample and preferably not less than 15mm from the upper edge of the test sample. During the test, the test sample is fixed on the experimental device, but no additional mechanical stress should be transmitted to the test sample.
Evaluation of test results:>
Unless otherwise specified in the relevant specifications, if the test sample does not burn or burn, or all meet the following conditions, it is considered to have passed the burn Wire test:
a) If the flame or glow of the test sample is extinguished within 30s after removing the glow wire, that is, testa+ 30s; Tissue paper should not ignite.
ZRS-3H glow wire tester according to IEC60695-2-1, IEC60695-2-10, IEC60695-2-11, IEC60695-2-12, IEC60695-2-13 (IOS5169.10, IOS5169.11, IOS5169.12, IOS5169.13),