To some, cost is all important.
There's a lot to be said for knowing just how the house will be laid out. and having an adequate number of sockets were say a desktop will live. And of course for things like aerial outlets and phone points - if anyone still uses a landline. ;-) Luckily, this house is fairly easy to add sockets to with a cellar and cavity internal walls. And carpets which can be lifted.
But very difficult to predict. When planning the rewire here I went way over the top but the sparky gently pointed this out and cut it back to something much more reasonable.
It more or less boiled down to double sockets conviently positioned either side of any opening, (door, large window), maximum distance between double sockets of about 3 m and any corner that wouldn't have one from the above got one. Additional was a coax and double Cat5 in diagonal corners across the door (all our doors enter rooms in a corner).
On 16 Jan 2014, John Rumm grunted:
Is that figure based on the total area of each room/hallway added up, or the area of the rectangle that the property sits on (which in my case is quite different as the footprint here is L-shaped
Floor area served by the ring. If you're arguing about whether to include the area taken by partitions you need two rings :)
I did a basic re-wire when buying this house - a condition of the mortgage
- and then a more comprehensive job as each room or area was re-decorated.
The only place I did a 'saturation rig' on was the through lounge which was the first area to be finished. 2 doubles on each of the original walls
- apart from the dividing one, obviously. And to be perfectly honest many have really never been needed. I'm a bit OCD about trailing cables, so have used a mains distribution unit for the Hi-Fi etc rather than having everything on individual 13 amp outlets.
One of the things many get wrong is the need for convenient Hoovering sockets. ;-)
I have 13 circuits at the mo.....
I have:
outside & Garage lights loft lights first floor lights ground floor lights smoke, heat, CO and intruder alarms Ootside & Garage ring main loft ring main Kitchen & untility ring main lounge & master bedroom ring main Dormer bedroom, box bedroom, 3rd reception ring main back bedroom * dinging room ring main Boiler Cooker
Maybe you should've had a word with Dave L's sparky :-P
Quite...
Although common sense needs to apply. One ring for 120m^2 of bedrooms etc will probably still be lightly loaded. However 30m^2 of kitchen and utility can fully load another.
My either side of openings doors or large windows cures that. There are lot of sockets and I expect some may never get used but I'd prefer that to having extensions to get power where it is needed.
The CU's, yes plural, for the bit of the house that has been rewired house 14 cicuits, spread over 4 RCDS.
I actually have 13 RCBOs in the one consumer unit, with a 2 pole isolator switch.
ever since switching from RCD & MCB based CUs to 100% RCBO's I've not had a single nuisance trip since.
The circuits were planned to give extra integrity.
I'm actually going to be adding a 14th circuit, for my shed and greenhouse at the bottom of the garden.....
my house for the record is a 4/5 bedroom house. (I have a 3rd reception room which is flexible, i.e. a 5th bedroom, an office or a 3rd reception room. I've already turned the downstairs toilet/cloakroom into a shower room.
I've never really paid attention to exactly *what* was put in the new consumer unit in 2009, but looking just now they are all RCBOs, and say
30mA, with units labelled "B32" on the three power rings and B40, B16, B20, for the various other circuits and B6 for the several lighting circuits and a towel radiator heater.Michael
Is that now classed as a historic rule of thumb?
Is it historical?
(or has table 8A OSG gone from later revisions of the 17th?)
That's interesting - I'll have to look at mine... (5 bedrooms, 3 reception on 3 floors, plus cellar and detached double garag e, all on a single ring, though the garage is fed as a fused spur. Done by the previous occupant, who was an electrician, and seemed to have done the minimum necessary in most cases...)
As with most instructions, they are guidance for situations where the designer does not know better. So for example, if you knew that a circuit was going be near to fully loaded covering a much smaller floor area, then you would not use the guidance to justify overloading it by pushing it to cover more. Likewise, covering a larger area when you know that the total load will be very low would IMHO also be a reasonable design decision.
However in your case, it does seem to be rather excessive in a number of respects, and fails the basic test of "discrimination" - i.e. limiting the impact of a fault to the area where it occurred. With your current setup, a trip on that ring circuit will lose power to pretty much most of the property by the sounds of it.
What I do is wire the cellar and ground floor on one ring, the upstairs and attic on another ring, and have one socket (clearly labelled) next to the CU (in the cellar) that's on the *upstairs* ring, so if I have the downstairs power off, there's still a socket available.
I don't have any way of working upstairs with the power off, though, I need to use a 30-foot extension lead thrown out of the window to do that.
jgh
After rewiring and decorating my place, I realised I had to retro-fit a socket at chest height to plug the iron into.
jgh
Hmm, not if there's an interruption in gas or oil supply and with say 5 bedrooms, each have a 2kW heater on the go!
You have that number of heaters on standby?
I do keep two just in case the heating breaks. But not 5.
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.