Electricity and Home Entertainment....

[funkydiver]

I move into my new house next month and the first job is a full rewire... I'd like to throw a couple of questions to the forum for a bit of advice.

1. Whilst running the electricity cables, I also want to throw in a few cables for home automation/entertainment including CAT6 ethernet. Signal interference aside (wiring diagrams reduce the cable running parallel where possible) is it acceptable to run twin & earth in the same wall space as co-ax, CAT6, speaker wire, telephone cable, etc... or do the two elements need to be separated physically?

2. I'm also looking at using a range of modular faceplates from Clipsal / RPP (here's the Clipsal Range) which seem to allow this style of multiple connection at the face. Will this affect the way I run the cabling?

3. I'm looking to do the rewire in the main myself (I'm happy with the routing, load calculations, etc), and I understand that I have to get a Qualified electrician to check it before it goes live... what qualifications am I asking for when I do a ring round?? And how much is a reasonable amount to expect to pay?

Many thanks for your help in advance...

 

[plugwash]

they need to either be a set distance apart or be in seperate compartments of a conduit/trunking system

if they need to cross and are not in conduit/trunking then electrical insulation material should be placed between them

modular units should be easy to terminate though make sure you look at how the modules are loaded *before* wiring them you don't want to end up with the wire making it impossible to fit the modules to the plate

there are no regs yet that require you to have it checked but i would advise getting a decent sparky in to check it when it's done the most important thing to check for is public liability cover though you should possiblly also ask about qualifications if they don't answer than you worry

the order of the rewire is up to you but here is what seems sensible to me particularlly if you want to use old wiring to pull new wiring

first put in a couple of 16A radials to double sockets in the most critical locations don't connect theese yet though

swap out the old cu: there isn't anything that hard about this you first pull out the service fuse where power enters your house (don't worry about breaking seals to do this) then run fresh 25mm tails from the meter terminals (again another seal you may have to break but don't worry) to your new cu use a split load CU, lights and alarms on non rcd everything else on non rcd connect the 16 radials to give you some power for lighting and living while you do the main rewire you could put the old cuircuits on the new board temporerorilly (use the same size breakers as before or as close as you can) instead of the initial radials but i wouldn't do this if the wiring is in a really bad state

now just put in the new cuircuits on by one connecting them up as you wire them

and finally when they are all in place get it checked

i would advise trying to get the new color code cable if you can for a complete rewire job it'll be much neater to extend once the transition period is over

 

[funkydiver]

lights and alarms on non rcd everything else on non rcd

I take it the "everything else" is ON rcd??

 

[plugwash]

yeah sorry i made a typo it was meant to be

lights and alarms on non rcd everything else on rcd
also it is considered by many to be a good idea to put in dedicated cuircuits for freezers and put them on the non rcd side (i think this is done in case the rcd trips while you are on holiday and destroys everything in your freezer)

the only things that actually have to be on rcd are sockets that could reasonbally supply outdoor ewuipment but in parctice it is normal practice to put stuff on the rcd unless there is specific reason not to (computer equipment may also come under this catagory)

and get a CU with plenty of space spare over what you calculate for your rewire and of a decent brand (prefereablly MK) so you can get more breakers in future when you need them

 

[Big_Spark]

I move into my new house next month and the first job is a full rewire... I'd like to throw a couple of questions to the forum for a bit of advice.

1. Whilst running the electricity cables, I also want to throw in a few cables for home automation/entertainment including CAT6 ethernet. Signal interference aside (wiring diagrams reduce the cable running parallel where possible) is it acceptable to run twin & earth in the same wall space as co-ax, CAT6, speaker wire, telephone cable, etc... or do the two elements need to be separated physically?

If the circuits are sound, then there is normally not an issue in practice, however this can never be guaranteed and there should be electric seperation of circuits of power and communication.

Ethernet Cat6 should not be too much of an issue, as if the cable is actually Cat6 cable, it is screened anyway. I would, however, suggest that you do your best to keep the cables apart where possible.

2. I'm also looking at using a range of modular faceplates from Clipsal / RPP (here's the Clipsal Range) which seem to allow this style of multiple connection at the face. Will this affect the way I run the cabling?

I would not touch clipsal with a barge pole..if fact I would not urinate on their factory if it was burning. Cheap, nasty, unadulterated cr*p.

You would be far better off using MK or a brand of similar quality. Most people do not know that all MK products come with a full lifetime guarantee against failure so long as it has been used as intended and not abused in the process of use. Cost wise there is not too much difference these days, so long as you buy from a wholesaler not a shed.

3. I'm looking to do the rewire in the main myself (I'm happy with the routing, load calculations, etc), and I understand that I have to get a Qualified electrician to check it before it goes live... what qualifications am I asking for when I do a ring round?? And how much is a reasonable amount to expect to pay?

If you want to have the installation checked when you complete, phone an NICEIC registered contractor in your area and ask them if they will do a full test and inspect on your installation to allow connection. I would not suggest you tell them you did it, they will may refuse to do the test . Tell them a non NICEIC spark did it for you but the EB need the certificate for connection. Saves a lot of messing about that way.

Regarding planning your rewire, you might want to have a read of this It is not 100% finished yet, and it is only an example, but it will help a bit perhaps.

 

[funkydiver]

Many thanks for your expeditious replies...

I feel like I've been a member for years already

Following the recommendations... I've found the ideal solution for the wiring cluster that's going into the living room...

Regards keeping the two wiring elements seperate, would a common earth be acceptable, linking the two back boxes, or am I going to be looking at a seperate earthing circuit? This "setup" is going to be located behind my TV / Amp / XBox in the lounge and want to try and make surethe jobs done right first time rather than mess about with dodgy wiring in the future blowing everything through a short circuit...

Using existing wiring is not an option... there's currently a 3 fuse (wire type) consumer unit in a fethching bakelite finish insitu at present... not bad for a four bedroom house!!!

 

[plugwash]

oh yeah one other point when rewiring

check earthing type of supply and bonding of pipework

it is normal to use a specially designed main earth terminal like. if you don't have one fit this

to this should be run the main supply earth the earth wire to the CU and the main equipotential bonds to service pipes (water and gas generally) the main equipotential bonds should be 10mm in most cases though in some TNC-S systems they may need to be larger the wire from the main earth termina to the CU should be 16mm

earthing systems

TN-S most common in the uk earth is joined to sheath of supply cable no special action required but the main earth wire should be at least 16mm and if not it should be replaced

TNC-S the electricity board will terminate A nutral wire to a main earth terminal for you provideing your earth you should ask them what size your main equipotential bonding conductors shuld be in this case

TT this is where you have a seperate rod. this really needs to be porfessionally tested though that could probablly wait until after the bulk of your rewire when you have the whole system tested
furthermore in this case you must use a 100ma time delay rcd in place of the main switch in your split CU and all sockets must be on the normal 30MA rcd

WATER PIPE this is no longer allowed as the source fo your earth you will need to get an eath rod professionally installed or ask for a PME install to be done by your regional electricity company

 

[plugwash]

ahh i forgot to say

PME is the same thing as TNC-S

 

[Big_Spark]

it is normal to use a specially designed main earth terminal like this if you don't have one fit one

Plug, whilst you do normally find one, you do not have to use one. So long as all main bonding conductors are linked to a common point at the mains, there is no problem, and many manufacturers, all of the decent models, have extra terminal on the Earth Bars of the Consumer units for this exact situation.

However, this can be a biitch if you have larger than usual earth cores.

 

[AdamW]

A point to note when wiring your network is the radii of cable bends. If you want to turn a corner too tightly then you will reduce the available bandwidth of the cable and thus the speed of your network will suffer.

I believe for Cat-6 cables the recommended minimum bend is a radius of 5cm, although the less tight you can make the bend, the better. Where possible have nice long, sweeping bends or even better, no bends! Cat-6 is pretty thick so bending it any tighter would kink it anyway.

As you are using cat-6 I am assuming that you wish to have the option of gigabit ethernet either immediately or in the future. So, you will need to wire all 4 pairs. And you will need good quality wall-jacks. Gigabit ethernet is more sensitive to bend radius (this sounds like a broken record!) and I am sure the figure of 30cm has come up in the past.

For the audio and video side of your installation, I believe there are products available now that can use Cat-5 or above cables for such things. I have never tried them so don't know how the quality is, but as you are doing a full rewire anyway you may as well run the necessary co-ax cables (provided you know where you want your absolutely vital new plasma screen to hang )

Oh, just an off-the topic note: if anyone is planning to hang a plasma screen on a wall, note that despite being flat they are still heavy! I have heard stories of people hanging a screen on a stud wall with plasterboard fixings, only to have it fall off 5 minutes later. And let's just say they don't bounce!

 

[plugwash]

i'm sure i heared that main equipotention bonding cables should be fixed with 2 screws each

and i don't think this is possible in your average CU besides main earth terminals aren't hugely expensive and it seems standard practice to fit them nowadays

 

[Big_Spark]

i'm sure i heared that main equipotention bonding cables should be fixed with 2 screws each

and i don't think this is possible in your average CU besides main earth terminals aren't hugely expensive and it seems standard practice to fit them nowadays

There is a common consensus to fit them, and it is the better option, but there is no regulation about fitting them. Ensuring they have a sound connection is preferable to the amount of screws holding them in place.

To be perfectly honest I always price jobs with a 8way block and ensure our Guys use it.

 

[funkydiver]

Thankyou all.... my wiring diagrams (and cost calculations!!) are taking a new lease of life...

Just need to find a supplier who'll give me a fab deal.. lol