I do understand the diversity allowances etc. I just want to get this job right for the LBA and maybe napit. The house I am rewiring has 4 floors.the problem is the customer ( partners son) he has decided on separate cooker and hob (more than 2 metres) hence 2 ways probably allowing 7kw for each.I can push at 3 light circuits( no 100 watt bulbs nowadays ) 4 rings plus kitchen ring (5). Keeping fridge on its own circuit, smoke alarm ,boiler, oh and he might want 10 kW shower. I'm getting about 179 amps on a 100 amp breaker. Are you allowed to use one ring for two floors. Or perhaps separate cu for shower any suggestions anybody please
Hi Garry The circuits would be straight forward if you adopt this suggestion: 50A radial for shower 32A radial for oven 32A radial for hob 32A ring for kitchen sockets 20A radial for each floor for other sockets 6A radial for each floor for lights Total 12 circuits Wire the boiler on a switched spur on one of the socket circuits, wire smoke detectors on to one of the four lighting circuits, don't bother with a separate circuit for the fridge/freezer just use a socket on the kitchen ring. Regards
It doesn't matter whether you put the hob and oven on the same or separate circuits - the actual load taken will be the same. You need to look at the actual appliance loadings and the intended use. In some cases the suggested diversity for cookers is very generous; in others it's insufficient to allow for a large household cooking everything for christmas dinner for twenty. You can have hob and oven on separate isolation switches within 2 metres of the appliances but on the same circuit. Likewise the ring circuits - whether you use 2 or 4 the actual load will be the same (and probably minimal). You probably need at least 4 lighting circuits (even ignoring the 100 W per point 'rule') to minimise inconvenience in the event of a fault. You don't need a separate kitchen ring; spread the kitchen across two other rings which will probably be lightly loaded, so giving some redundancy in trhe event of a fault and a total of 64 A for kitchen appliances. Do seriously consider emergency lighting over the stairs, connected to the local lighting circuits.
I'm fitting a board tomorrow, 14 way - 5 rings, 1 x 6mm hob, 2 x 2.5 ovens, 2 x immersions (backup only-**** knows why there is 2) 1 x socket radial and 3 lighting circuits. Not worked out the diversity but I'm happy everything will be ok on the same board.
As pointed out above, you could have one ring for the entire house or 10 rings at one per room, The stuff they plug in will be the same no matter how you wire it. Yet if you wired 10 rings some smart **** would be shouting for a bigger supply. Common sense is the name of the game.
I know whether you have 1ring over 2 floors or 2separate rings makes no difference power wise but more than one ring is 32amps plus 40% of remaining. I just want to satisfy that LBA man.the oven and hob is more than 3 metres away so separate isolators. Do not know what power oven or hob they might want in so I was been safe at approximating 7000 watts each, give or take with diversity about 16 amps each. Then there is shower, fridge. Smoke alarms and boiler. I know it should be ok but I've never dealt with the powers that be and roughly how much more than 100 amps would be acceptable. PS,as for emergency lighting, obviously you don't mean stand by.do you mean something that is always on or dawn to dusk or MI cable. Just one other thing, would you put fridge,freezer on separate cb or in with ring. I worry about earth leakage tripping rcd and losing power to freezer
There is no requirement to pay any attention to the views of the On-Site Guide on diversity (or anything else).
It's never insufficient. Not everything can always be simultaneously energised - and even if it can the stat will cycle the elements on and off.
The section on diversity in it is really totally out of date. How can you expect a ring to draw 32a then 40% for other rings? Maybe if it's a dedicated ring for a kitchen...but for the rest of the house? A few lights and a tv, phone chargers, hair dryer, games, yea that's gonna really cane it. I think the guide assumes your only going to put in one ring for the whole house, maybe if your stuck in the 1970's. Anyway I go with 16a/20a radials on clusters of 3 double sockets these days and a 32a radial for the kitchen.
agreed. sometimes we are all guilty of reading too much in to this stuff and forgetting about reality! There are loads of houses still with one 32 amp ring and it works perfectly.
Read my post again, you don't need ring circuits they are a PITA to wire and test and are prone to misuse and problems. The only place you really need a 32A circuit (ring or radial) is in the kitchen. Everywhere else 16A or 20A radial is more than enough. One ring circuit covering the entire house does not conform with wiring regulations, nothing to do with load capacity it is more to do with circuit management to minimise inconvenience in the event of a fault. Too much emphasis these days on 32A ring circuits, totally baffles me.
Agreed UP Hence my inital comment about 4 ighting circuits and 4 rings (or radials) to keep each floor independant and prevent 1 floor taking out another. Kind regards
There aint no specific reg preventing that mate....? A few maybe hint at it, but always willing to learn
If you take a radial to one bedroom and another radial to the other bedroom you might as well link them together and make a ring, one less way used up in the CU and you need all the ways you can get with the amount of oven and microwave and god knows what else they have in kitchens nowadays.
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