Ellis has called on the IET to eradicate a longstanding installation issue that causes serious health, safety and system integrity problems by reclassifying cable cleats as protective equipment.
Richard Shaw, Managing Director of Ellis, said: “For many years we have banged the drum about the sheer importance of correctly cleating cables and the dangers that arise if short cuts are taken, yet still we see far too many installations where this advice has been ignored and corners cut simply to save money.
“Where to point the finger of blame is a complex and difficult problem, but how to resolve the situation is straightforward,” he continued. “By reclassifying cable cleats as protective equipment you would immediately see them being correctly specified and installed in every new electrical installation.”
Ellis’ argument for this reclassification is based on three key points:
1) In the event of a short circuit fault the maximum electromechanical stress between the conductors occurs during the first quarter cycle – i.e. at or before 0.005 seconds.
2) Typical circuit breakers and other protection devices don’t trip and interrupt a fault until between three and five cycles (0.06 to 0.1 seconds).
3) In contrast, correctly specified cable cleats earn their crust during the all-important first quarter cycle, ensuring the cables remain intact and operational.
“What this means in practice is that without properly specified cable cleats, the time, effort and expense spent assembling a circuit breaking system will all go to waste as any electrical installation will be irrevocably damaged by electromechanical stresses long before the short circuit protection devices are put to the test.”
Cable cleats restrain electrical cables in a manner that can withstand the forces they generate, including those generated during a short circuit. Without them, the dangers are obvious – costly damage to cables and cable management systems, plus the risk to life posed by incorrectly or poorly restrained live cables.
“What always need to be remembered when considering cable cleats is that in a short circuit situation all an incorrectly specified product will do is add to the shrapnel,” added Richard.