Distribution in Bedsits - Which would be best

[daver]

Have a friend with a building company, who has just converted a large house into 9 bedsits. His father does all his electrical work and as usual it gets to the end and i'm called in to help out with with the final fix.

The stall is, that we are waiting for Scottish power to install the new 3 phase but he was pondering on what was the best way to distribute.

Not exactly sure of the total amount of circuits but what I have seen

6 Showers
6 Lighting
6 Radials
Immersion
Provision for feed to garage
Smoke
Emergency Lighting

I suggested 24 way TP&N board and individual RCBO's, but this will be very expensive.

His dad initial thought was RCD on each phase, but this could be a nightmare as the board is in a cellar and would be fun if cellar light was on the one that went off. His second suggestion was 3 x 8 way consumer units and divide equally.

Any thoughts on a cost effective method.

Thanks in advance.

DaveR

 

[trebor]

As the bedsits are effectively self contained premises they would require a seperate ccu in each one, I reckon I would go for a twelve way tpn at the source with a sub main and suitably rated circuit breaker for each bedsit, this will leave 3 spare ways for l/lords and garage etc. It also has the avantage of keeping the final circuits short and allows for easy alterations or additions in the future, each bedsits ccu would of course be split load 17th edition

 

[i=p/u]

id say 20A rcbo radial to each room and spur for light, i lived in bed sit one time and all thats ever used in there is tv and iron

 

[i=p/u]

oh and showers on there own circuit= 9+6 and so on so id say 24 way board wouldnt be far off a good workings out??? but dont listen to me im a plonker when come to electrics

 

[trebor]

whoops ! forgot the showers

 

[Engineer54]

i=p/u,

Did you actually take notice of anything Trebor posted (post2)?? He correctly pointed out that as ''Bed-Sits'' they would each require there own mini CU!! So you can forget about a single DB supplying these 9 bed-sits with individual circuits!!!

Any thoughts how the owners/tenants are going to be billed for there electrical consumption, using yours and your friends fathers distribution ideas??? ...Your idea about spurring off a power circuit for the lighting, just beggars believe!!....

 

[i=p/u]

why not if its fuesd and he wants to keep costs down. an for the bills it should be in the weekly rent buddie

 

[Engineer54]

why not if its fuesd and he wants to keep costs down. an for the bills it should be in the weekly rent buddie

Standards sort of spring to mind!!! And as this is rented accommodation they should be of the highest, for obvious reasons!!
So one tenant could be paying for another tenants consumption, especially if one or more are high consumption users, and the others aren't !!

 

[daver]

As usual ends up in a slanging match without people reading correctly. I was after cost effective thoughts.

Final Fix, which normally means all cables are in.

All bedsits are finished to a very high standard including large walk in showers, brand new furniture and 42" LCD, including one in the communal kitchen (so I did forget about the Kitchen ring). The rent includes everything, so there is no issue about who uses what.

QUOTE "Your idea about spurring off a power circuit for the lighting, just beggars believe!!...."

Where does it say that? And since when have you not been allowed to spur off, to provide a lighting circuit.

What I was trying to say for the cost element was, he was going to protect each phase with an RCD and split everything equaly across the phases. The problem being, when Doris in Flat 3, trips the RCD with her faulty hairdryer, then 6 other circuits go off. Which may include the lighting circuit to the cellar, where the board is. Easily solved with an emergency light.


As it is, its 1 radial, 1 lighting per floor. 1 shower per flat and 3 showers running off boiler.
As it is all the cabling is done and routed to the incoming mains in the cellar.

I was only after thoughts, not a slanging match.

DaveR

 

[malcolmsanford]

I don't think Engineer54 was slanging you mate but i=p/u.

To be honest it looks like your going to have to make the best out of what is not a very well designed install. If the sits are done to that good a standard, the clients will be paying top dollar for them, and myself I would be rathered peed, if Doris in 3 does trip that radial and my flat goes out I would not be happy.

So wether you fit RCDs at the origin is mute really, because if her hairdryer trips the MCB for that radial, then whoever else is on it will also leave them without power.

Your only recourse, as the sockets, and the cables, the showers will need to be RCD protected is either as the father says you split it into 3 single boards with an upfront RCD controling the board or a double pole switch isolator with RCBO's.

The upfront will at least give you phase discrimination, the RCBO's will give you the ideal discrimination.

As been mentioned the ideal scenario would have been to wire each sit independently and to be honest if your putting 42" LCD in each room, nice furniture and walk in showers, would it have been that prohibitive to perhaps made each room it's own little sub installation.

It seems like normal that a lot of thought as gone into the design of the sits, but as usual not the electrics of it ...................I think your gonig to have to make the best of a bad job.

 

[TPES]

Carehome I've been on has had a tp&n board giving me 48 single ways, every way except 2 has RCBOs, each room is on it's own RFC and has it's own lighting circuit, has cost a fortune but is the best way possible for inconvenience to any other room.

Obviously I've had no need to provide local DB's and meters.

 

[daver]

Thanks Malcolm and TPES. My only suggestion was the TP&N with individual RCBO's. It was his dads face when I said that. He was seeing £20 for breakers and not a couple of pounds.

Thats when the talk of 3 individual 8 way Consumer units with RCD came into the frame

It was badly designed and as you say, everything else is more important and electrics are not planned.

It will still be the same with the RCBO's as 3 sits sockets will go off. if its tripped.

Thanks to everyone, will advise accordingly

Cheers