How BASEC Tests and Approves Fire Cables
Gaining BASEC product approval for a fire performance cable is a prestigious mark of quality for a cable manufacturer. The process of gaining this approval is straightforward, but a number of requirements need to be passed before approval is granted.
BASEC approval may differ from some other testing / certification processes which look at a limited range of tests. BASEC approval includes all the tests specified for a cable type and its constituent materials, not just a single fire test. A cable may be seen to pass a single fire test, but if its construction is incorrect or its materials do not last very long this would be a poor value product.
BASEC operates a four-stage process for approval:
- Initial inspection of the factory, including production equipment, quality control systems, laboratory equipment and testing. Assessment is against BASEC's Product Certification Requirements and the requirements of the relevant cable and test standards. BASEC requires factories to test their own cables regularly.
- Initial type testing of the cables, covering the range of sizes and cores. BASEC conducts a full range of tests on each cable type, including electrical, mechanical, materials, chemical and fire tests as specified in the cable standard and in all the subsidiary standards referred to. Only when all tests are passed, and the factory is acceptable, is BASEC Approval awarded.
- Regular visits to the factory, up to four times each year, for rechecking the production processes, reviewing any problems. At the same time BASEC selects samples from the factory for independent checking.
- Regular retesting of the cables. Cables are retested up to four times a year, with up to 150 samples being tested on an annual basis. Over a three-year certification cycle, all sizes and core combinations are tested to a full range of tests, including fire tests.
Fire tests for cables vary from cable standard to cable standard. Almost all cables, whether fire performance or not, undergo a simple flame propagation test using a gas flame. Cables with special fire performance characteristics undergo one or more tests from a range of possible tests. These tests are sometimes available in a range of possible severity or survival time. For example, BS 7629-1 / BS 5839-1 cables may be tested to BS EN 50200 and classified as PH30, PH60 or PH120 depending on the duration of the fire test in minutes.
Recently some more severe fire tests have been developed to assist architects and fire engineers in achieving high levels of safety in buildings using active fire protection systems such as smoke extract systems, which rely on continuity of power supply during a fire. An example is the test method specified in BS 8491, which is referred to in BS 7346-6 (Components for smoke and heat control systems -specifications for cable systems). Shortly this test will be included into the British Standard for fire resistant armoured cables, BS 7846.
BASEC is often asked about "low smoke halogen free" type cables, and the requirements for this categorization. Again, relevant cable standards specify that two tests are used – smoke emission in a 3m cube, and corrosive and acid gas emissions in a tube furnace.
When specifying fire performance cables it is not usually necessary to specify the individual tests a cable must pass. These are listed and specified in the cable standard, so simply specifying that a cable must fully comply with, for example, BS 7629-1 / BS 5839-1, means that all the relevant fire tests included in this standard must have been passed. A BASEC Approval for this cable means that all such tests have been passed and are being regularly re-checked.
Contact Details and Archive...
Related Articles...