1. RESISTANCE TO FIRE ALONE TESTING (as prescribed in BS 6387 CLAUSE D2 / IEC60331-11)
The cable in question is mounted horizontally into a chamber, constructed of Zintec, with up to 5 ring clamps. It is then exposed to a 610mm long tube-type gas burner.Electrical continuity is checked throughout a 3-hour exposure to the gas burner set at an appropriate temperature.
2. RESISTANCE TO FIRE WITH WATER (BS 6387 CLAUSE D3)
The cable is held with a metal support and the assembly is housed in an electrically earthed test frame which is held in a large, watertight, Stainless Steel trough. The frame is also fitted with gas burners, a water sprinkler head & means to power and test the continuity of the cables. A 400mm section of the cable in question is exposed to flames at 650°C, produced by an array of 5 gas burners mounted on 100mm centres, for a period of 15 minutes. The water spray is then switched on, in order to comply with the standard BS 6387 (D3), the cable must maintain electrical integrity whilst both water and flames impinge on the cable for a further 15 minutes.
3. RESISTANCE TO FIRE WITH MECHANICAL SHOCK (BS 6387 CLAUSE D4/IEC60331-11/ BS EN 50200)
The cable is mounted on a vertical board made from non combustible material (900mm ´300mm ´9mm). This vertical board is mounted onto rubber bushes such that it will resist shock from a bar which is driven to fall on to the top edge of the board every 30 seconds. The powered cable must maintain electrical continuity during a 15 minutes exposure to flames from an array of burners and impact from the falling bar.