How are plastic enclosures tested for heat and fire resistance?

We evaluate the durability of our plastic enclosures against excessive heat and fire using an indirect flame method, known as the glow wire test, in line with IEC standards. This determines the tendency of a product to resist ignition. If ignition occurs, the procedure also provides an insight into the ability of the object to self-extinguish flames and to prevent the spread or propagation of fire through dripping.

Excessive heat and fire can compromise the performance and functional integrity of electrical enclosures, and these conditions can arise where connections are overloaded or components overheat. We are committed to making sure our enclosures withstand them.

To determine these capabilities as specified by international standards, the equipment under test is first put in place and a thin cotton fibre cloth, or ‘tissue’ paper, is positioned directly below it. The sample is then brought into contact for 30 seconds with a hot filament, whose exact temperature depends on the product being examined:

• Parts containing live components: 960°C ±15°C

• Cavity wall parts: 850°C ±15°C

• All other components: 650°C ±15°C

The test is passed if the enclosure does not burn or glow, or if, after the filament is removed, the glow is extinguished independently within 30 seconds. The tissue paper must also not be ignited by any falling parts from the sample.

There is more detail on the variety of tests we conduct and the methods we follow at https://www.spelsberg.com/service/technical-information/technical-information/tests-and-test-methods-according-to-iec-/en-standard/ and on our quality promise at https://www.spelsberg.com/about-us/quality-promise/quality-promise/

By conducting this test on our products, we can deliver solutions that effectively protect both the equipment they contain and the surrounding environment.