UL746A Clause 34 Glow-Wire Ignitability Tester To Determine The Relative Ignitability
34 Glow-Wire Ignitability Test
34.1 General
34.1 .1 The test method for the determination of ignitability of an insulating material from an electrically heated wire is described in the Method for Glow-Wire Ignitability Test on Materials, IEC 695-2-1 /3. Flammability Testing Equipment
34.1 .2 The Glow-Wire Ignition Temperature (GWIT) is to be assigned as the temperature which is 25°C (45°F) higher than that temperature of the tip of the glow-wire which does not cause ignition during three consecutive tests.
34.2 Significance Flammability Testing Equipment
34.2.1 Either during normal operation, under unusual conditions, or as a result of malfunctions, some components of an electrical apparatus, such as wires or other conductors may become abnormally hot.
When these overheated parts are in intimate contact with the insulating material, ignition may occur. This test is intended to determine the relative ignitability of insulating materials under these conditions. Flammability Testing Equipment
Standard:IEC60695-2-10, IEC60695-2-13 and UL746A.
Application:This device simulates the thermal stress test of glowing component or heat source like overload resistance or ignition source which is caused in a short time. It is suitable for electric and electronic products, household appliances and other material to do fire hazard testing. It is also used in the No flame ignition source fire test to test initiation temperature and flammability index of related glowing filament.
Test sample:Electrical equipment and its components and parts, solid electrical insulating materials and other solid combustible materials. Flammability Testing Equipment
Feature: Test principle: the glowing filament whose material and shape is required(Ni77/Cr20) is heated to the testing temperature of 550 ℃ ~ 960 ℃ for 1 min by using the glow wire tester with large current. Then using required pressure (0.95N) vertically burns the test sample for 30s. By observing whether the test sample and bedding object ignite or the burning time, the users can judge the ignition danger of electric and electronic products. It is used for the ignition test, ignition temperature (GWIT) test, flammability test and flammability index (GWFI) test of solid insulating material and other solid combustible material. Flammability Testing Equipment
Parameters:
ParametersModel | GW-2(Touch screen) |
Working voltage | 220V/50Hz |
Control operation mode | PLC control, 7 inch color touch screen operation, with infrared remote control |
Glowing filament | Ф4mm ± 0.04mm (> 77 % Ni/20 ± 1 % Cr) special standard ring shape,horizontal standing |
Specimen pressure on glowing filament | 0.95N±0.1N |
Maximum depth of heating | 7mm ± 0.5mm Flammability Testing Equipment |
Specimen movement speed | 10mm /s ~ 25mm /s |
Temperature calibration | Calibration temperature:960°±10°C, the hot wire by electric heating |
Thermocouple: RS imported 1mm armour nickel-chromium/nickel/ nickel aluminum K-Thermocouple, temperature resistance 1100° | |
Silver foil: purity 99.8%, area :2m², thickness:0.06mm | |
Tray | A layer of silk paper (12~30g/m³) is covered on the 10mm thick pine board, with a distance of 200±5mm below the test sample |
Test chamber | >0.5 cube,sample distance from the inside of the box is greater than 100mm, black yogon background,background illuminance ≤ 20Lx,with exhaust fan |
Testing time | 30s±1s Flammability Testing Equipment |
Test procedure | The test sample is driven by the car and automatic run, the car will return automatically after glow-wire entered the test sample of 7mm |
Lighting | Equip with lighting in the test chamber, with control |
Dimension | 1100*550*1200mm,140kg |