Discuss How to work out the total design load to find my swa cable size in the Electrical Forum area at ElectriciansForums.net
Hi the earthing arrangement is TN-C-S and 100a supply, I was thinking time delayed if was going into existing board as not to trip the house, or just Henley block and have its own sub board non rcd at house end and having a tt at outbuilding end
Hi apologies, I just assumed discrimination if it was in the main existing board, the sub board would not need RCD, the tt I was just learnt many years ago if the out building was some distance from the house to install tt as there is no extraneous parts made from wood and plastic so no need for pme, sorry guys if to old skool. I do think it is best to use the existing TNCS.I'll ask again, why does the submain need RCD protection?
How would a time delayed RCD prevent something in the house tripping?
Why does it need a TT arrangement at the outbuilding? What is preventing you from using, what is presumably, a perfectly good TNCS earth?
120.36amp,,,, but if I do the 3 sockets rings as 20amp radials diversity will come in at 96.36amp..
This is my teenage daughters alone in my house!Unless they leave the hot taps running, turn the heaters to max, keep refilling the kettle and take seven extra fanheaters in there they are not going to use 120A. The people would overheat even if the cables don't.
This makes no sense. The load is determined by what people plug in, not by how you wire the sockets. What makes even less sense is the total consumption. Think about the heat you get from 120A (almost all electrical power gets converted to heat before it leaves the room)
120 x 230 = 27.6kW. Unless they leave the hot taps running, turn the heaters to max, keep refilling the kettle and take seven extra fanheaters in there they are not going to use 120A. The people would overheat even if the cables don't. If the installed heaters are adequate, the RFCs are going to see a couple of amps total except when the kettle is on.
Also, 2kW lighting? You can't buy GLS lamps any more
Hi the main, supply is 100a in the house this is to power an outbuildingI think you need to contact your DNO to arrange a new 100A supply.
He knows that ted he’s saying that if the upfront fuse is 100a and is already serving the house you’d need to deduct that usage (after diversity before you could think about using it on the outbuilding as well,Hi the main, supply is 100a in the house this is to power an outbuilding
What is the total load after diversity in the house at present?
The reason I ask is if it’s 80amps then you only have 20 amps left for the outbuilding. Will this be enough?
The 16mm swa is clipped direct 3core, 94amps current carrying capacity is what I found out from the technical information from the wholesaler when contacted them, as I couldn't find it in the books and online was getting different amounts. In your knowledge what would you say the current carrying capacity of 16mm swa 3core clipped direct and buried is.Although 96 amps sounds like an awful lot for what your talking about, presuming the swa is buried in a duct or ground or whatever I can't work out how you got 16mm
Clipped direct is fine I was only taking a guess at buriedThe 16mm swa is clipped direct 3core, 94amps current carrying capacity is what I found out from the technical information from the wholesaler when contacted them, as I couldn't find it in the books and online was getting different amounts. In your knowledge what would you say the current carrying capacity of 16mm swa 3core clipped direct and buried is.
Didn’t realise you where working on someone else’s house. I thought you where working on your own property.
Is your boss an electrician?
Does he know about loading and cable calcs.
You quite rightly point out it’s your liability if your the qualified supervisor, not his.
If the property does not have a big enough supply, tell him and the customer.
Your profile is limited so I don’t know the extent of your experience or qualifications.
Reply to How to work out the total design load to find my swa cable size in the Electrical Forum area at ElectriciansForums.net
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