A:There are many safety precautions like voltage, abrasion resistance, chemical resistance, etc., that should be considered in choosing any kind of electrical cable, including that for fire alarms. However, there are some notable fire-related safety precautions to consider as well.
A:Firstly, it is important to isolate the installation from the mains supply before attempting to check or repair flooded cables. For obvious reasons, the sooner the flood recedes and action is taken the more likely it is that the cables will not be adversely affected. Find out what to do when the water subsides.
A:•Corrosive and acid gas
•Mass of zinc coating for galvanised wire armour
•Smoke emission
•Flame propagation test for multiple cables
•Shrinkage test on insulation
•Abrasion test
A:The voltage rating of a cable is the highest voltage that may be continuously applied to a cable construction in compliance with the relevant cable standard or specification.
Voltage rating figures for cables are normally expressed in A.C. RMS. (Alternating Current Root Mean Square) and are written as a figure Uo/U (Um)
Uo = Rated voltage phase to Earth
U = Rated voltage phase to phase
Um = Maximum system
A:The directive currently applies to the materials used in the production of electronic devices belonging to the following categories:
• Large and small household appliances
• IT and telecommunications equipment
• Consumer equipment
• Light bulbs and other lighting equipment
• Electronic and electrical tools
• Toys, leisure and sports equipment
• Medical devices
• Monitoring/control instruments
• Automatic dispensers
• Semiconductor devices
A:The RoHS is a directive of the European Parliament and the European Union Council that aims to reduce the use of certain dangerous substances commonly used in electric and electronic equipment (EEE). EU legislation restricts the use of hazardous substances in electrical and electronic equipment and promotes the collection and recycling of such equipment in which consumers can return their used EEE waste free of charge. The legislation also requires certain hazardous substances (heavy metals such as lead, mercury, cadmium, and hexavalent chromium and flame retardants such as polybrominated biphenyls (PBB) or polybrominated diphenyl ethers (PBDE)) to be substituted by safer alternatives.
