New Electrical circuit. Suggestions for a "HUB"

[Moocats]

Hi gents,

I've been reading through some of these threads for a while, very impressed with the community here. Now it is I who needs some advice.



I'm in the process of dividing my large living room in two to create a 4th bedroom/office space.

I had been concerned with potential overload as the one outlet already in this space is on an existing busy circuit shared with the kitchen. I believe at this point; a new circuit is the best way to proceed.

I plan to wire directly from the breaker to this new room to bypass this problem and then remove the existing outlet from the kitchen circuit.

However; looking at the position of the main breaker. I believe the best way to do this would be to wire to some sort of hub in this room; then split off 5-6 lines from here to each electrical outlet. Because of the odd shape of the space; wiring from one socket to the next, to the next and so forth will actually be harder. Is there some sort of mini breaker box or some other wall mountable junction device I could use for this?

Also; I'm having a hard time sourcing appropriate electrical wire online, some of the obvious big name store web sites seem woefully lacking in electrical installation categories. does anyone have any link suggestions for a reasonably priced online source for good quality insulated wire for this?

Much obliged for the help guys,

Kane

 

[Taylortwocities]

1., do not worry about overload by adding sockets for bedroom/office use. The additional loading will be very small.
Many houses, mine included, have just one ring finasl circuit for every socket in the place.

2. if you were to add another circuit, ths is notifiable to your local authority and you would need to pay their fee, and expect to have all of the necessary calibrated test equipment to demonstrate to them that the work you have done meets BS7671. see here //www.diynot.com/wiki/Electrics:part_p:DIY-Electrical-Work-and-the-Law

3. You do not 'hub' electrical circuits, its either a ring, or a radial. In both cases, the wiring goes from socket to socket, not to a central spider point.

4. Electrical cabling must conform to rigorous double insulated requirements. There are many on line resellers such as screwfix.com and http://www.tlc-direct.co.uk

5. All socket circuits must now be protected by an RCD. Does your consumer unit have this feature?

From your post, it would seem that you might not have the right competence to do this work. perhaps you are more used to data cabling?
Suggest you find a local electrician to advise you.

 

[AndyPRK]

Try www.screwfix.com
For supplies

 

[ericmark]

One should not put any more than three wires in one hole as you can't be certain all wires will be gripped so maximum for socket is ring in, ring out, and a single spur.

We do use a sort of hub with kitchens where we install a grid switch which controls a load of sockets using terminal blocks like this

in an adaptable box one could feed all sockets from a central point but there are a number of reasons for not doing this.

1) It's not what others would expect to find.
2) If not using the standard ring or radial circuit you would need to design from scratch working out all loadings and demonstrating unlikely to be overloaded you would need to be good at maths.
3) The hub would need to be accessible and would likely look ugly.

A ring will normally be supplied from a 32A MCB or RCBO and the house will have between a 60A and 100A main fuse excessive number of rings would likely either not be required or would overload main incoming fuse. Where one wants extra circuits so a fault on one will not affect another the normal way would be to move from ring to radial and reduce the MCB/RCBO to 20A.

But in college we would have a bench with maybe 40 sockets all from the same RCBO powering computers and the like without a problem. These were radial circuits so only 20A to start with.

So yes maybe you want more sockets but unlikely you need a new circuit. With domestic new circuits are a problem in that you need to either use a scheme member electrician or inform the LABC before starting. You will need to complete an insulation certificate which in turn means hiring expensive equipment to test it so the results can be entered on the form. If going away from standard likely LABC would want to see some qualifications to show you had the design skills required.

 

[Moocats]

Firstly I'd like to thank everyone for the very helpful responses.

1) I was concerned with potential overload due to the fact the kitchen appliances, including, washer, dryer, fridge/freezer and dish washer plus the less used appliances are all on one and I also forgot to mention this is also shared with the main living room so add the expected electronics there.

Adding those along with my often permanently on two power hog desktop PC's and peripherals I was concerned I'd be taxing it too far.


2) This is vital information I wasn't armed with. Coupled with what you said above. I will not be adding a new circuit.

3) The idea was that the circuit would be radial but because of the several directions I wanted to start from one source. As it seems that's not appropriate I'll have a rethink.

4) This I did know and I can't believe I forgot screwfix! Thanks very much.

5) I actually have two consumer units one handles all heating the other is for all the other general purpose and dedicated circuits in the house. Neither have RCD so I'll be sorting that.


You are right in your assumption. I've laid more data cable over the years than Virgin media! I have added sole sockets, light-fittings and their light-switches in the past however this has all been done on readily accessible existing infrastructure.

This project, atleast for me is a larger one.

Thanks to eric also for answering the literal question even though I'll not be proceeding with any idea of a central hub and will just build a standard radial circuit.


One can never be too careful with electrics so I have decided the best way to proceed is to have a certified spark come and assess the best path to proceed and then do some of the actual work my self to have him review and approve.

Thankyou very much for the help guys, much obliged to you.

 

[Moocats]

One last point I forgot.

If RCD is a requirement now; would that mean landlords both private and council would be required to update consumer units? Not applicable to me but to my brother it's a relevant question.

 

[flameport]

Newly installed sockets and most other things require an RCD, so one would have to be installed when new items are installed.

Unfortunately, there is no requirement to upgrade older systems, therefore if an older installation does not have one, it can remain just as it is.

 

[ricicle]

One should not put any more than three wires in one hole as you can't be certain all wires will be gripped so maximum for socket is ring in, ring out, and a single spur.

.

Can we have a regulation number for that or a link for that information Eric ?

 

[JohnW2]

One should not put any more than three wires in one hole as you can't be certain all wires will be gripped so maximum for socket is ring in, ring out, and a single spur.

Can we have a regulation number for that or a link for that information Eric ?

As you imply, I'm sure there is no such explicit regulation. Having said that, I don't recall having seen a socket 'rated' for more than three conductors per terminal - even MK ones are only 'rated' for three 2.5 mm² or three 4.0 mm² conductors (or two 6.0 mm² ones) - so, at least (perhaps!) until Amd 3 comes along next year, the regulation constraining one to 'obey' MIs probably does, in effect, limit one to three conductors per socket terminal.

Kind Regards, John

 

[EFLImpudence]

Would that be considered 'instructions' or merely information?

 

[JohnW2]

Would that be considered 'instructions' or merely information?

Ooooh - I've never seen anyone try that one before You tell me!

I imagine those 'terminal capacity' figures appear on the bit of paper which comes with one of their sockets, in exactly the same manner as all the other 'information' there - and the impression I get is that most people interpret the whole of that bit of paper as representing "MIs"!

Kind Regards, John

 

[EFLImpudence]

Well, I would expect a 'max' or 'must not exceed' or similar.

After all, it could be used for a radial and there is no mention of 1.5mm².
(Note the 13A per socket outlet)

Technical specification
Electrical

Voltage rating:
250V a.c.

Current rating:
13A per socket outlet
(except 3 gang which is 13 amp in total)

Terminal capacity:
Live, neutral & earth
3 x 2.5mm2
3 x 4mm2
2 x 6mm2
(standard)
(Dual earth terminals on list Nos.
K781, K2657, K2737, K2746, K2757)

Physical
Ambient operating temperature:
–5°C to +40°C
(not to exceed an average of more than 25°C in any 24
hour period)

IP rating:
IP2XD

Max. installation altitude:
2000 metres

 

[JohnW2]

Well, I would expect a 'max' or 'must not exceed' or similar. After all, it could be used for a radial and there is no mention of 1.5mm².

I think we need a lawyer and/or linguist. To me, "terminal capacity" actually does imply 'the maximum it can take' ... as if I said that the capacity of my car's petrol tank is 60 litres, or the capacity of a stadium was 25.000 persons etc. etc. ... hence the phrase 'filled to capacity'.

(Note the 13A per socket outlet)

We've been through that umpteen times before. No-one, not even the technical support guy at MK I spoke to, seems to know what 'socket outlet' means in that context - i.e. whether a double socket has one or two 'socket outlets'!!

Kind Regards, John

 

[EFLImpudence]

I think we need a lawyer and/or linguist. To me, "terminal capacity" actually does imply 'the maximum it can take' ... as if I said that the capacity of my car's petrol tank is 60 litres,

Yes, but if actually possible to get 65 in, how would that affect things?

(Note the 13A per socket outlet),

We've been through that umpteen times before. No-one, not even the technical support guy at MK I spoke to, seems to know what 'socket outlet' means in that context - i.e. whether a double socket has one or two 'socket outlets'!!

Ah, but note:
(except 3 gang which is 13 amp in total)

 

[JohnW2]

... as if I said that the capacity of my car's petrol tank is 60 litres,

Yes, but if actually possible to get 65 in, how would that affect things?

I reckon that it would mean that the 'capacity' statement was incorrect. If the 'capacity' was 60 litres, to my mind that means that one can't get 65 litres into it. As I said,we need a lawyer or, at least, a lingusit!

We've been through that umpteen times before. No-one, not even the technical support guy at MK I spoke to, seems to know what 'socket outlet' means in that context - i.e. whether a double socket has one or two 'socket outlets'!!

Ah, but note: (except 3 gang which is 13 amp in total)

We've also been through that umpteen times. Again, 'the man from MK' was just as confused as the rest of us (saying that the specs were written by the marketing dept!!) - but he did refer to the oft-quoted fact that 22A total for a significant period of time is known to cause significant damage to an MK double socket.

Kind Regards, John