Hi Guys,

I'm hoping someone can give me some guidance; we have a project where we have 2 parallel trefoil 20kv MV cables entering a RMU from a concrete cable chamber directly under the switchroom. The cables are cleated horizontally on cable ladder every 600mm and sweep upwards into the RMU gland plate, approx 1000mm from last cleat to each gland (see attached pic). Fault current at RMU is 20kA for 3 sec. Cables are around 40mm OD and separate to approx 100mm apart from each other where they enter the gland plate. Given this vertical rise to gland plate is relatively short and within the recommended spacing requirements for horizontal cables in trefoil, is there a need to install additional short circuit rated supports and cable cleats? If there is we would obviously have to design a frame that surrounded the group of 6 single core cables and cleat each one separately....it just seems a bit OTT?....Thoughts / Comments?





Thanks

Seansasta