AS NZS IEC 60331.1:2017 pdf free
AS NZS IEC 60331.1:2017 pdf free.Tests for electric cables under fire conditions – Circuit integrity
The test ladder shall consist of a steel framework as shown in Figure 1. The two central vertical elements of the ladder shall be adjustable in order to accommodate different sizes of cable under test. The test ladder shall be (1 200±100) mm long and (600±50) mm high, and the total mass of the test ladder shall be (18±1) kg. Ballast, if required, shall be placed on the steel supports.
NOTE 1 Angle iron approximately 45 mm wide and 6 mm thick, with suitable slots cut to allow for fixing of the bolts or saddles, has been found to be a suitable material for construction of the ladder.Each horizontal element shall have a mounting hole not more than 200 mm from each end, the exact position and diameter being determined by the particular supporting bush and supporting framework used. The test ladder shall be fastened to a rigid support by four bonded rubber bushes of hardness 50 – 60 Shore A fitted between the horizontal steel elements of the ladder and the support framework, as shown in Figures 1 and 2 so as to allow movement under impact.
NOTE 2 A typical rubber bush, which has been found to be suitable, is shown in Figure 4.The source of heat shall be a ribbon type propane gas burner with a nominal burner face length of 500 mm with a Venturi mixer. A centre-feed burner is recommended. The nominal burner face width shall be 10 mm. The face of the burner shall have three staggered rows of drilled holes, nominally 1,32 mm in diameter and drilled at centres 3,2 mm from one another, as shown in Figure 5. Additionally, a row of small holes milled on each side of the burner plate, to serve as pilot holes for keeping the flame burning, is permitted.
During the test, a current for continuity checking shall be passed through all conductors of the test specimen. This shall be provided by a three-phase star connected or single-phase transformer(s) of sufficient capacity to maintain the test voltage up to the maximum leakage current allowable.AS NZS IEC 60331.1 pdf free.
