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.
A:A spark test is an inline voltage test used either during cable manufacturing or during a rewinding process. Spark testing is primarily for low voltage insulations and medium voltage non-conducting jacket or sheaths. The test unit generates an electrical cloud around the cable which in high frequency AC units appears as a blue corona around the cable. Any pin holes or faults in the insulation will cause a grounding of the electrical field and this flow of current is used to register an insulation fault.
