Explanation of testing procedures according to VDE 0472, Part 804
A cable sample measuring 60 cm (2 ft.) in length is vertically suspended in the center of a metal box 1200 mm tall by 300 mm wide by 400 mm deep (circa 47 x 12 x 16“). A gas burner with a defined flame is installed in such a way that its axis is tilted by 45° in reference to the vertical. The flame hits the cable sample about 100 mm/4“ above the lower end. The flame burns until the conductor or the topmost metal shielding shows through, but no longer than 20 seconds. To pass the test, either the test sample must not catch fire, or if it does start to burn it must then extinguish itself, and whatever damage is caused by the flame‘s heat must fail to reach the top end of the tested cable sample.
A cable sample measuring 60 cm (about 2 ft. in length) is vertically suspended in the center of a metal box (1200 mm tall by 300 mm wide by 400 mm deep (circa 47 x 12 x 16“). A gas burner with a defined flame is installed in a way that its axis is tilted by 45° in reference to the vertical. The flame hits the cable sample about 100 mm/4“ above the lower end for about 1 – 2 minutes, depending on the weight of the sample. The test is successful if the test sample did not burn or if the flame that resulted extinguished itself and the damage caused by the heat of the flame did not reach the top end of the tested cable sample.
Cable samples, each measuring 360 cm/14“ in length, are fastened side by side to a ladder-like test rack. This test rack is inserted vertically into a kiln, at a distance of 150 mm/6“ to the back of the kiln. The flame is directed right against the flame samples at a height of approximately 60 cm/2 ft., at a temperature of approximately 800°C/1472°F, by a burner about 250 mm/10“ wide. The exposure time is 20 minutes. The test is successful if the ensuing flame extinguishes itself and the damage caused by the heat of the flame did not reach the top end of the tested cable sample.