What kind of incoming electrical connections are these?

[ban-all-sheds]

So now I am looking for 6 x CUs which are obviously amendment 3 (i.e. metal clad). I don't imagine I need more than a 10 way. Any recommendations?

Surely your electrician is the person to ask?

After all - she will be the one to install them and she will be the one to have to give a warranty for her work - you can't just give her a box of CUs and simply expect her to use them.

 

[newconnection]

That's how the SSE chap fitted the meters

So now I am looking for 6 x CUs which are obviously amendment 3 (i.e. metal clad). I don't imagine I need more than a 10 way. Any recommendations?

Surely your electrician is the person to ask?

After all - she will be the one to install them and she will be the one to have to give a warranty for her work - you can't just give her a box of CUs and simply expect her to use them.

I'm sure the electrician will have his own preference but I don't mind paying a bit more for a better product, hence, doing my homework now.

 

[ban-all-sheds]

Then ask the electrician to provide a "better" product.

 

[newconnection]

Then ask the electrician to provide a "better" product.

I will but there is no law against posting here and asking for recommendations.

 

[newconnection]

Looking a the Hager catalogue, what's the difference between a 10 way 5+5 versus a 10 way configurable?

Secondly, there will be suspended ceilings in the flats which will contain Rockwool RW3 or RW5 insulation for sound proofing as well as retaining heat. There will also be insulation under timber suspended floors on the ground floor. Are there any special considerations for wiring with such insulation in place? I don't want to compromise safety nor the sound insulation of the materials being used.

 

[RF Lighting]

Your electrician will know all this.

 

[newconnection]

I know he will (hopefully), I am meeting him in a few days. Now how about you tell me something I don't know? Jeez! I am not trying to take anyone's job, just do some homework and stay on top of things. Imagine if it was this bad on car forums:

Question: "My car won't start, I think it could be the starter or the battery but i'm not sure, any ideas?"
Response 1: "Ask your mechanic".
Response 2: "Your mechanic will know".

 

[PBC_1966]

Looking a the Hager catalogue, what's the difference between a 10 way 5+5 versus a 10 way configurable?

The former is a fixed configuration with 5 ways on each side of the board. The latter can be changed so that you could have, for example, 3 on one side and 7 on the other, or 4 on one side and 6 on the other.

Secondly, there will be suspended ceilings in the flats which will contain Rockwool RW3 or RW5 insulation for sound proofing as well as retaining heat. There will also be insulation under timber suspended floors on the ground floor. Are there any special considerations for wiring with such insulation in place? I don't want to compromise safety nor the sound insulation of the materials being used.

Cables are rated for different maximum currents depending upon the method of installation. Since the thermal insulation - by design, obviously - traps heat, cables run through it are rated for a lower maximum current than cables which, for example, are just clipped to a surface but otherwise exposed to free air.

 

[kai]

Looking a the Hager catalogue, what's the difference between a 10 way 5+5 versus a 10 way configurable?

The former is a fixed configuration with 5 ways on each side of the board. The latter can be changed so that you could have, for example, 3 on one side and 7 on the other, or 4 on one side and 6 on the other.

The Ten Way configurable is a more modern version of the old-fashioned fixed way boards, meaning that you can vary the number of ways on each side of the split to suit your needs, and not be restricted in your options - better still configurable boards are exactly the same price as their old fashioned inflexible configuration ones.

 

[kai]

Never rely solely on an electrician to get basic things right, such as number and position of socket outlets, or the type of consumer unit - no doubt if you rely solely on him, as other hardened people keep suggesting, all your sockets will be in the wrong places for your own needs, and there will be a cheap make of unknown brand consumer board with nil spare ways, featuring hard to get breakers in the case of future need.

 

[newconnection]

Never rely solely on an electrician to get basic things right, such as number and position of socket outlets, or the type of consumer unit - no doubt if you rely solely on him, as other hardened people keep suggesting, all your sockets will be in the wrong places for your own needs, and there will be a cheap make of unknown brand consumer board with nil spare ways, featuring hard to get breakers in the case of future need.

Completely agree.

I want to work in partnership - he is the expert but I want to know what's going on and why. I have decided the number and position of sockets and drawn plans to show this - easier for us both. I have also stripped the place back to bare brick too. If he has a good justifiable suggestion, I'm happy to listen and change things - and vice versa too, I hope.

 

[PBC_1966]

he is the expert

Unfortunately, it's clear that many "qualified" electricians are not only not experts, but actually have a pretty shaky grasp of some of the fundamentals.

 

[cjard]

You'll get this in the Sparks forum, and for reasonable reason.. Bodged electrics kill regularly, and it's not always DIY. The guys here don't think that encouraging DIY electrics is a good idea and there are a lot of "oh I just want to buy the gear, my electrician mate will install it" posts
Yeah right.
" so doc, my mate has this itch in.. Uh.. That area.."

I'm the same, always asking for gear advice and I'm sure everyone here thinks I'm DIY sparking my new build. Short of posting up the certificates that my Sparky mate uses to prove he is authorised when working on large sites, there ain't a right lot I can do

For my sins I've picked up a load of BG bear and my spark is happy with it. The RCBOs (twenty of em!) came from screwfix. Due to a pricing error they ended up about a tenner each. Finding a BG metal clad amendment 3 unit was harder and at 40 quid quite the premium over the 17 quid outgoing no compliant clearance item I could have got from screwfix. Amusingly the spark then said "what the bloody hell did you buy one of those for?" So all the messing around to get a metal box for the fire to burn away in happily was probably not needed. I could have had two smaller metal CUs but it would have made the install more of a pain in the arse.

Talk to your spark, as he might not believe in amendment 3 yet and it could save you a bit of cash.


Ps in answer to your question, a 5+5 is a split unit, one master switch goes to two RCD, and from there to two banks of MCBs. It's a good idea, means you don't lose all lighting etc if the dodgy cooker trips one RCD. The 10 way one might not have two RCD supplied with it even though it's likely to be the same metal box. It's usually cheaper to by boxes wih RCDs in than get RCDs separately. Be ware also that the number of ways may refer to the number of open slots in the panel and an RCD takes up two slots, so if you buy a 10 way metal box it might not be physically support 10mcbs if you put two rcds in it. Better just to get a fully populated cu (maybe with some spare unused mcb) that has at least the number of mcb you want as it's more economical than buying bits, even if mcb are only pence

Note you kinda need your house wired on some kind of left/right, front/back or "circulation space lighting on different RCD to one most likely to trip due to appliances" split to keep the lights, rather than the traditional up/down (which is a daft idea anyway coz you end up with a downstairs ring final that has every juice hungry appliance on it while the upstairs one has.. A hairdryer occasionally)

 

[newconnection]

Thanks for explanations regarding the difference between 5+5 and a 10.

How many circuits can one RCD deal with?

With regards to the wiring configuration, this property will be self-contained flats so each will have it's own meter and CU. I imagine most sparks will just want one ring for all the sockets in the flat but it would be nice (but perhaps overkill?) to have a ring for each room to give maximum flexibility - e.g. bed 1 ring, bed 2 ring, lounge ring etc., but then if you do the same with the lights you could end up need a larger CU than originally required.

 

[ban-all-sheds]

I know he will (hopefully), I am meeting him in a few days. Now how about you tell me something I don't know?

There is not the space here to tell you everything you don't know about electrical installation design.

But there might be space to tell you that if you want your electrician to sign this declaration:

I being the person responsible for the design of the electrical installation (as indicated by my signature below), particulars of which are described above, having exercised reasonable skill and care when carrying out the design hereby CERTIFY that the said work for which I have been responsible is to the best of my knowledge and belief in accordance with BS 7671:2008, amended to 2015 except for the departures, if any, detailed as follows:

you have to let him do the design, which includes speccing the CU.