advice on max demand

[BES]

abit of advice please from you wise people
cu change for assesment:
circuits&mcb
shower 40a
cooker 32a
ringx1(14 points)32a
garage 20a
immerson 16a
sockets radial(2 points)16a
sockets radal(4 ponts)16a
lights up 6a
lights down 6a
main fuse 80a
what ever way try a.using osg b.highest mcb then 40% of rest. i cant get the max demand below 80a. asked supplier(central networks via npower) to up grade to 100a fuse but they said they dont fit 100a anymore max off 80a.
help please
thanks neil

 

[telectrix]

so enter it as 80A then. sorted.

 

[BES]

cheers telectrx
yeh but what if assessor question how i come to this figure?

 

[telectrix]

you tell him. 100% shower then 40% of the rest added up. when all said and done, it's unlikely that the cooker and shower will be on together with a large load on the socket circuits. if you want to get it down a bit, apply diversity to the cooker, tghat will shave about 10-14 A off.

 

[sparkie710]

do they not fit 100a fuse anymore ? or am i on a totally different boat right now ?

 

[telectrix]

well. it ain't my boat, coz it sank in conwy harbour.

 

[BES]

thats what was told sparkie710 news to me as well when i ask why the guy replied"dont know?"

 

[BES]

done that telectrix but still over 80a
cooker has socket as well
i completly agree with what your saying just dont know how the assessor will veiw it just want no mistakes.

 

[telectrix]

well. what i would do is to tell the assessor that you have worked it out using the 100% biggest load and 40% of the rest, but common sense tells you that this figure is higher than you anticipate, due to the fact that the circuits will not be simultaneously loaded to that extent.

 

[Octopus]

Add up all the circuits and multiply by 0.4

IMHO a house with a single power shower and cooker will never get anywhere near 80A

 

[TPES]

They will fit 100a as they do on new builds, it maybe that you have the equivalent to 16mm entering the service head in which case they won't fit 100a as it's a few amps away from it current carrying capacity. So 80a will be your max

 

[BES]

telectrix w
what figure would you put in the box 100% of biggest and 40% equals 98amps

 

[telectrix]

in that case i would enter 80A, as that is what the supply fuse is rated at. saves argument.

 

[BES]

cheers murdoch
i agree it will never get near the 80a
but thought it was 100% of biggest load then 40% of rest in my case 98amps so what figure would you put in box

 

[telectrix]

look at it this way. the supply fuse is 80A, so that's the max. demand they can have. (not allowing for short term overload of the fuse)