NICEIC Certification Scheme Max demand on eic for niceic ---

[J.C.E]

Morning

i have calculated my max demand as 69.6a (sum of mcb's x 0.4)
and on my eic i have n/v the main head fuse- but on the sticker it says 60/80a (i know it could actually be 60 or 80 or 100 inside)

this is the job i am using for my niceic initial assessment

will this be asked about by him/her- and if i just explain the chances of the cooker, shower, ALL sockets and hot tub all running at full load at the same time is not likely. And he should be happy?

im sure this is the case in domestic anyways that calculated max demand ususlly is > main head fuse
but obviously really not wanting to have to pay out for another half day assessment for any slip ups lol

 

[telectrix]

another way would be to calculate the load of each circuit after applying diversity. this would probably bring the figure even lower, but as a rule of thumb, your estimate is OK. i'd round it down to 60A. oh, and you put> when you meant <. lol.

 

[J.C.E]

another way would be to calculate the load of each circuit after applying diversity. this would probably bring the figure even lower, but as a rule of thumb, your estimate is OK. i'd round it down to 60A. oh, and you put> when you meant <. lol.

thanks for quick reply tel

no i did mean > (if i was right or not is different matter lol)

like for example my case the calculated m.d is bigger than my possible 60a main head- and isn't this commonly the case in dimestic- but chances of everything running at f.l unlikely

 

[telectrix]

for assessment, i'd make sure that the max. demand you put on your cert. is less than the DNO fuse rating. otherwise the assessor will demand to know why you are exceeding the In of the fuse.

 

[J.C.E]

for assessment, i'd make sure that the max. demand you put on your cert. is less than the DNO fuse rating. otherwise the assessor will demand to know why you are exceeding the In of the fuse.

so if i put 60a on my cert and if he gets me to calc it which will come to 69.6- he will be happy for me to say its unlikely all circuits will run at f.l at the same time- hence why ive rounded down to 60a on my cert

 

[Octopus]

The reality is that the vast majority of homes won't get anywhere near 45 amps, let alone 60

Using the "add up the MCB's and multiply by 0.4 is too high IMHO, using 0.25 is probably more effective. Gone are the days of 6 breaker fuse boxes so the diversity rules are well out of touch if you ask me.

Hope this helps.

 

[HappyHippyDad]

I think you will find that you are panicking over nothing Jo.

I remember this exact same conversation 3 or so years ago on this site when I was about to have my first assessment.

The answers I received where:

1. Put down 60A as Max demand as if the fuse is 60A then its protected anyway. (Not very correct really!!)
2. Write the figure in kVA as this will just confuse the assessor. (said in jest I think)
3. A domestic supply is extremely unlikely to use over 60A anyway so it doesn't matter.
4. Just x0.4 as this generally gives a lower figure than diversity figures in the OSG. (I realise you've already done this)

None of which are terribly helpful to you!! Sorry!

I can say the assessor didn't even blink at the 60A figure I had in the Max demand box (my actual max demand using diversity was about 63A I think) and I very, very much doubt yours will.

I would personally put 60A as the max demand as I dont think that is dangerous to do so and the assessor is more likely to question a figure greater than 60A in the max demand box (if you put your cutout fuse size as possibly being 60A) than question you about diversity.

Most of the assessors are human beings so you could also mention (but only if he mentions it first, otherwise keep quiet!!) that the majority of CU's have a big bunch of circuit breakers now compared to the rewirable boards and houses that used to have just one ring now have perhaps 3 rings, (and also 2,3 or 4 lighting circuits as opposed to 1) which brings up the calulated max demand, but doesn't necessarily bring up actual max demand. Unless he's a bit silly he'll know that already and agree with you.

Good luck and let us know how it goes?

 

[J.C.E]

Cheers happyhippy

thought it would be the case really
keep getting told their there to pass you- guess it makes sense- want you to pass so they get there annual d.d off me!

 

[conrad]

I put main fuse size... Also told thay you could ask a client etc for there energy consumption bill.