NOTES ON FRLS AND FR SHEATHED CABLES
Oxygen Index (ASTM D 2863) The criterion for burning is presence of percentage of oxygen in air. By mixing oxygen and nitrogen at various percentages this test finds at what percentage of oxygen the standard specimen starts burning. Higher the oxygen index higher the resistance to get ignited. Min. oxygen index shall be 30%. Temperature Index (ASTM D 2863) Temperature index is the temperature at which the oxygen index of the material becomes 21.This test is carried out usually by extrapolation after the oxygen index is measured at various temperatures. Minimum temperature index shall be 250 ºC. Smoke Density (ASTM D 2843) This parameter relates to measuring and observing relative amounts of smoke produced by the burning or decomposition of materials. This test is carried out in accordance with ASTM D 2843. The measurements are made in terms of loss of light transmission through a collected volume of smoke produced under control standardized conditions. Generally requirement by customer is smoke density rating less than 60%. Acid Gas Emission (IEC 60754-1) During burning of cable materials acid gases are evolved especially hydrogen chloride. The gas emission is evaluated in accordance with test method IEC 60754-1, where approximately 1 gm. of the material is pyrolysed at 800 0 C in a combustion tube and resultant gases are analyzed. Flame Retardance (IEC 60332-1) A single cable sample is clamped vertically. The Bunsen or other similar burner is arranged at 45 Degree to the axis of the cable sample, applying flame at 475 mm below to top clamp. The flame is applied for a period of time depending upon the diameter of the cable.
The test requirement is that after all burning has ceased the charred or affected portion shall not have reached within 50 mm from the top clamp.
Flame Retardance Test (IEC 60332 -3) This test is carried out to check flame retardant properties of bunched cables. Three categories of tests namely category "A", "B" and "C" have been defined according to quantity of combustible material available over unit length. Cable pieces are tied on vertical ladder and flame is applied from a horizontal ladder. After the specified time the burner is removed. All parameters are pre defined according to specification. The charred portion is measured and compared with the standards to decide on acceptability.
Special PVC Compounds with Additional Requirements which OCI can provide:
Property
Material
FR
FRLS 30 250 60 20 %
FRRT
Oxygen Index (Min.) Temperature Index (Min.) Smoke Density Rating (Max.) Acid Gas Generation (Max.) Flammability Test*
30 250
30 250 - 17%
- -
IEC 60332-1 and IEC 60332-3-24
IEC 60332-1 and IEC 60332-3-24
IEC 60332-1 and IEC 60332-3-24
* Based on specific request, we can provide compounds which can meet flammability requirements of IEC 60332-3-23 and IEC 60332-3-22
6 MKK XXS002-02/01-12-2014
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