Electrics - The plan for the downstairs

[dunny]

Just finished planning out the power outlets, lights etc that I will have in the downstairs of the barn I am converting:-

25 outside lights (low level)
10 outside lights (high level)
51 double sockets
11 normal single light switches
7 fused spurs
36 Cat 5 outlets
5 AV controls
12 ceiling speakers
2 B and O ceiling speakers
1 B and O sensor
11 Cat 5 programmable switches
5 coax aerial sockets
2 smoke alarms (1 heat)
3 consumer units

Not done the requirements for heating controls (if required), fans (if required) outside lights on poles , CCTV power or outside power...

Does this sound like overkill (I like to think its future proofing)??

D

 

[didthathurt]

I take it that means you're creating 3 separate dwellings?

 

[dunny]

No - one dwelling, but is very big....

D

 

[jj4091]

I cannot really see how anyone can say whether that is overkill or not without seeing it nor knowing what your requirements are & the uses of each room. Or did you just feel like bragging that you have a big one?

 

[dunny]

No not at all - I am trying to budget for what will be needed to complete the conversion. I copied the plan and then put in all of the things that I thought I would need room by room. When I added it up at the end I was stunned to realise how much kit will be required just for the downstairs!!! I was wondering whether I had just gone overboard by putting a socket in each corner, a fused spur by each proposed TV location and outside lights right around the building (it gets very dark at night as there is a distinct lack of street lights).

By the time I do the upstairs I am worried that there may be more power requirements than can be supported by the 100A supply. I was trying to get a more experienced view as to whether these numbers seemed off the scale or not??

 

[didthathurt]

I'll edit cos I reread your first post about the 3 phase supply. Are you splitting a phase from a 3 phase supply and bringing a single phase into the barn? If so, why 3 CU's?

 

[dunny]

Are you splitting a phase from a 3 phase supply and bringing a single phase into the barn? If so, why 3 CU's?

Yes thats correct.

Advice from a previous post but also I wanted to put a seperate one in running the AV stuff including the lights (as they are connected to an automated cabinet). One for the main barn and one for the outside stuff.

Does this make sense??

D

 

[didthathurt]

Not IMHO. Even for what you describe, a single CU can have a good 20 circuits on it, can be split load or, even, be effectively 2 CU's in one box. One like this
http://cgi.ebay.co.uk/Split-Load-20...0092684023QQcategoryZ3188QQrdZ1QQcmdZViewItem
Can be arranged in all sorts of ways and could surely accommodate your needs.

The total load of 100Amps will not be solved by adding extra CU's - the DNO main fuse will, in all likelihood, limit you to 100Amps after diversity (to be honest, though, you'd have to really go some to blow one of those). The total load you will have to assume for those purposes will not depend on the kit you describe as much as the number and nature of the circuits installed and the ratings of the MCB's protecting them. You may well save a lot of time and money in the long run to consult an electrician at this stage - now is the time to get it right correcting it later could be very costly.

 

[JohnD]

I see no mention of non-RCD radials for hob, oven, freezer, immersion heater, boiler and burglar alarm.

3 CUs fed from submains is only worthwhile if you have separate dwellings or outbuildings; or e.g. a workshop with lots of machinery or a set of off-peak circuits like storage heaters or the pool heaters.

 

[dunny]

I most certainly will be consulting an electrician as this job is way beyond me. There is just so much stuff I dont know that I couldnt hope to do a proper job (even though I consider myself a competent DIYer).

Before I call one in though I need to be clear what I am asking him/her to do hence the reason for laying out the plan. I am not hung up on the 3 CU thing it just seemed sensible (and indicated by an answer in another thread) and that things could be neatly seperated in this way. One reason is that for the lights I want to fit a central control panel (giving automation to the lights) and this involves star wiring the lights to a central location.

The panel is powered from the CU and it seems sensible to have it located in the same place. Similarly for outside - their will be lights on poles, external power, gates, CCTV and the septic tank. I wouldnt want these to go down if something tripped the main CU.

I take your point about split load and effectively 2 CU's in the same box (2 would be located in the same place anyway so this could work) but I guess this amounts to the same thing.

I wasnt suggesting that fitting multiple CU's would help with staying beneath the 100A supply rating - I was just concerned with so much kit required for just the downstairs I would be getting close to the limit by the time I add the upstairs and the other bits and bobs on...

BTW - like all trades there are good and bad sparks - would like to have some clue of my requirements and whats sensible before I engage one so I stand a chance of spotting the difference...

D

 

[JohnD]

I think the suggestion of buying 3 CUs was a joke - there are people in here who like MEM, people who like MK, and people who like Hagar, so he suggested one of each to keep us all happy

We also have someone who works for the Co-Op and likes Heat Pumps.

 

[dunny]

Ahhhh. I see....

That went completely over my head. Maybe I should buy one of each to keep you all happy???

D

 

[sm1thson]

I think the suggestion of buying 3 CUs was a joke

yes, but if memory serves me correctly you have more CU's than average john, lol.

 

[dunny]

I see no mention of non-RCD radials for hob, oven, freezer, immersion heater, boiler and burglar alarm.

Boiler and heater will be in the same room as the CU (where the main electricity supply will enter the building) so will be straight forward as there is no internal decoration etc going in here.

Good point on oven/freezer. Now on the plan.

Not sure whats required for the alarm. Could it go on a ring or a radial feeding the CCTV??

EDIT - As for outside I know that I need to power up the septic tank, the outside lights, a store / office, 3 or 4 external outlets and potentially water feature/garden lighting further doen track. Can I install an external CU with waterproof protection etc for future use?? Doing this would save me trying to think of what I need outside just at the moment. Having said that the large outside lights (on poles) may need to be operated from inside and the cameras on these lights will need to be powered from inside for security reasons. Suggestions??
D

 

[jj4091]

When I added it up at the end I was stunned to realise how much kit will be required just for the downstairs!!! I was wondering whether I had just gone overboard by putting a socket in each corner, a fused spur by each proposed TV location.

Sorry, did not realise this was a continuing post, but I was only joking, I would however suggest you put at least 2 double sockets where your TV points go, for all the peripherals.Why an FCU?