SAFETY OF CABLING
HALOGEN FREE CABLES
Until recently most cables for installations were PVC sheathed and halogen free cables were only applied in a few special cases. However, a significant change of attitude and regulation is now developing in the market.
During a fire incident the most dangerous toxic gases emitted are acid gases such as hydrogen chloride (HCI), hydrogen fluoride (HF) and hydrogen bromide (HBr).
These gases occur during combustion of materials containing halogen materials: Chlorine, Fluorine and Bromine.
Consequently, insulation materials of cables should not contain halogen materials in response to the security requirements.
FIRE AND FLAME RETARDANCY CABLES
In public places, for example buildings, trains, subways as well as industrial facilities, electrical tables have to function whilst maintaining a high level of security for people and material.
The cables shall not cause the fire, nor spread it. A benefit for these cables is a better fire performance than possible for PVC cables.
The following ratings can be found for communication cables:
á Flame retardancy according to IEC 60332-1
á Fire retardancy according to IEC 60332-3
FIRE RETARDANCY CABLES
INTERNATIONAL STANDARDS (IEC 60332-3-25; IEC 60332-3-24)
Part 3 of IEC 60332 gives details of a test where a number of cables are bunched together to form various test sample installations.
Part 3-24 and Part 3-25 define different categories and their procedures of testing. The categories are distinguished by test duration, the volume of nonmetallic material of the test sample and the method of mounting the sample for the test.
IEC 60332-3-24 covers category C and IEC60 332-3-25 covers category D.
The difference between/both categories is the volume of non-metallic material of the test sample and the flame application time. Category 0 relates only to small cables of overall diameter 12 mm or smaller.
EUROPEAN STANDARDS (EN 50266-2-4; EN 50266-2-5; CEI 20-22)
EN 50266-2-4 Common tests methods for cables under fire condition. Test for vertically mounted bunched wires or cables. Category C
EN 50266-2-5 Common test methods for cables under fire conditions. Test for vertical flame spread of vertically-mounted bunched wires or cables. Category
D. Small Cables.
These European standards have been approved by CENELEC.