Determine the flame propagation tendency of cables intended for use in cable trays.
• Reference Standard
IEEE 1202 : IEEE standard for flame propagation testing of wire and cable
The length of each cable specimen or each cable bundle shall be 2.4 m ± 0.1 m mounted on the cable tray and shall be conditioned 25° C ± 5° C for at least 3 h immediately before commencing the test.
The burner flame with theoretical heat output of 20 kW (70,000 Btu/h) shall impinge on the specimens for a continuous period of 20 min.
After burning has ceased , the cable shall be wiped clean and the maximum extent of damage shall be determined as follow:
Cable char damage : the limit of charring shall be determined by pressing against the cable surface with a sharp object. In place where the surface of the cable changes from resilient to a brittle or crumbling surface , the limit of charring has been identified.
Non- cable char damage : the limit of cable damage shall be defined as the point where the overall diameter is visibly reduced or increased.
• Performance Requirement
The sample shall have complied with this standard and met the performance criteria if the length of cable damage does not exceed 1.5 m±25 mm in two tests by measuring the distance from the lower edge of the burner.