More Consumer Units?

TraineeSpark · Posted: Sun Dec 12, 2004 6:24 pm Post Subject: More Consumer Units?

I have read the other comments on consumer units/ overloading / maximum demand etc, but am still not 100% certain what it all amounts to. It seems to me the Regs say diversity cannot be applied at a C/U, but the NICEIC say a certain ammount of diversity can be applied. I appreciate there are no hard and fast rules, and the Regs can be vague at the best of times, but can someone please help clarify?

SwindonSpark · Posted: Sun Dec 12, 2004 7:55 pm Post Subject:

TraineeSpark, do you own a copy of the wiring regs or the on-site guide?

TraineeSpark · Posted: Mon Dec 13, 2004 6:36 pm Post Subject:

Got a copy of both, SwindonSpark. Why, have I missed something obvious that is staring me in the face.

plugwash · Posted: Mon Dec 13, 2004 6:49 pm Post Subject:

the diversity guidelines are just that guidelines

they don't take account of the fact that more cuircuits don't nessacerally mean more demand (think up/down ring vs one big ring vs 4 20A radials) neither do more sockets nessacerally mean more demand (just less extention leads)

normal practice is to size CU incomers and tails based on the value of the service fuse (based on the fact that if that fuse becomes prone to blowing there are going to have to be major changes round the CU area anyway)

SwindonSpark · Posted: Mon Dec 13, 2004 7:23 pm Post Subject:

TraineeSpark, read Appendix 1 of the On-Site Guide (page 84) - all will become clear.

TraineeSpark · Posted: Mon Dec 13, 2004 8:18 pm Post Subject:

SwindonSpark and PlugWash, thank you guys for clearing all this up for me. It was pretty much as I thought it to be, but I now see where my element of confusion came in. On-Site Guide, App 1, Table 1b, lists all the applicable Allowances for Diversity, but there is a little add-on at the bottom which goes on to say "It is important to ensure... sufficient rating to take total load... without application of diversity." I now see that that only applies to stat controlled water heaters, floor warming, and thermal storage space heating, and not the entire Table. How daft do I now feel

Anyway, thanks again gents for taking the time to answer my question.

ibforman · Posted: Sun Jan 30, 2005 8:01 pm Post Subject: Re: More Consumer Units?

TraineeSpark wrote:

I have read the other comments on consumer units/ overloading / maximum demand etc, but am still not 100% certain what it all amounts to. It seems to me the Regs say diversity cannot be applied at a C/U, but the NICEIC say a certain ammount of diversity can be applied. I appreciate there are no hard and fast rules, and the Regs can be vague at the best of times, but can someone please help clarify?

andy · Posted: Sun Jan 30, 2005 11:46 pm Post Subject: Re: More Consumer Units?

ibforman - ne reason so post to this thread?