Commercial/Industrial installation. Summary of installation:
Main feeder pillar contains TNCS incoming supply single phase 100A main fuse, 25mm DNO tails, meter, 100A double pole isolator switch, 25mm tails/16mm CPC to 63A rotary isolator, 10mm SWA cable 25m run to digital advertising panel into a 100A double pole main switch.
Digital advertising panel DB contains 7x C10 RCBOs for the 7 sections of the screen wired in 1.5mm flex.
My question is as follows.. is the main fuse head satisfactory protection for that 10mm SWA cable? Or does it require a switched fuse isolator as it is over 3m in length? Furthermore should it have its own DB and the SWA on a 50A MCB due to the cable size being 10mm and in ducting underground which can only take a maximum of 58 amps.
As it stands that cable has a 63amp rotary isolator & a 100A DP switch before the isolator. Meaning the only protection it has is that 100A main fuse which assuming it actually has a 100A fuse inside doesn’t provide satisfactory overload protection for this cable size in the first place.
Main feeder pillar contains TNCS incoming supply single phase 100A main fuse, 25mm DNO tails, meter, 100A double pole isolator switch, 25mm tails/16mm CPC to 63A rotary isolator, 10mm SWA cable 25m run to digital advertising panel into a 100A double pole main switch.
Digital advertising panel DB contains 7x C10 RCBOs for the 7 sections of the screen wired in 1.5mm flex.
My question is as follows.. is the main fuse head satisfactory protection for that 10mm SWA cable? Or does it require a switched fuse isolator as it is over 3m in length? Furthermore should it have its own DB and the SWA on a 50A MCB due to the cable size being 10mm and in ducting underground which can only take a maximum of 58 amps.
As it stands that cable has a 63amp rotary isolator & a 100A DP switch before the isolator. Meaning the only protection it has is that 100A main fuse which assuming it actually has a 100A fuse inside doesn’t provide satisfactory overload protection for this cable size in the first place.
