House Re-wire.

[flameport]

Am I right in saying that all burried cables that are less than 50mm must either be in protective trunking or protected by a 30ma RCD?

Yes. There are some other options (SWA, pyro etc.), but these are generally far more expensive than using an RCD. Many circuits will require an RCD anyway.
'Protective trunking' would mean steel conduit, NOT capping.
More than 50mm deep is not usually an option either, as this will cause structural problems with the wall.

Also the diagram for areas to run cables seems to be quite restrictive I think im interpreting it wrong.

Safe zones here:
//www.diynot.com/wiki/electrics:installation_techniques:walls
Basically, they are:
vertically and horizontally in line with a socket/switch
vertically within 150mm of a corner
horizontally within 150mm of a ceiling.

If im attaching cabling to a ceiling joist which will then be covered with insulation am I best running this inside trunking due to the amperage drop from 20 down to 13?

Perhaps, although this all depends on the size of cable and what it is being used for.

 

[unlucky]

The cable in question will be used for lighting the upstairs rooms so will be quite low load (6 lights), but im just thinking it would be better for futureproofing!

Something else, the current CU is located in an outbuilding / shed which is attached to the back of the house. the mains supply comes into the house about 6 meters away from the CU where the main fuse is located. The shed / Outbuiding isn't exactly in the best condition. I was wanting to know if there is a recomended length for the tails should be as I thought 6 meters was quite a long way.

Should I consider re-locating the new CU to inside the house? Oh the meter is located next to the current CU which is in the shed.

Sorry if thats confusing!

Phil

 

[RF Lighting]

It depends on the DNO, but generally tails should not exceed 3 meters in length.

Are you saying the meter is 6 meters from the cutout?

 

[LiamPope]

Also the diagram for areas to run cables seems to be quite restrictive I think im interpreting it wrong. Can I run cables anywhere in the wall provided they are outside of the 150mm safe zones and are run on horizontal/vertical planes?

The cables go in the safe zones.

 

[unlucky]

yeah the cutoff is 6 meters from the meter!!

The meter change company said it was a bit odd when they last came round. One thing I was thinking is if they change the location of anything surely it would be easier and safer to relocate the meter nearer to the main fuse?

The safe zones for running the cables makes more sense now, thanks!!

The cooker we have runs off a 13amp plug, would it be better to put this onto a permanently wired socket and a isolator switch?

 

[flameport]

The cooker we have runs off a 13amp plug, would it be better to put this onto a permanently wired socket and a isolator switch?

Put in a separate circuit, preferably 32A or more.
This will allow you (or anyone else) to have a larger cooker/oven in the future without installing a new circuit.

Insulation and lighting cables isn't normally an issue. Even derated by 50%, 1mm T+E is still rated at well over 6A.

 

[unlucky]

Thanks.

What should I do about the earth provision, whats the best way to tell if its adequate? Am i right in saying its the electricity companies responsibility to provide suitable earthing?

 

[ban-all-sheds]

Thanks.

What should I do about the earth provision, whats the best way to tell if its adequate?

Other brands of test equipment are available

Am i right in saying its the electricity companies responsibility to provide suitable earthing?

It is on new supplies, but hasn't always been so - can't remember when, if you Google for electricity supply quality continuity regulations you'll be able to work it out.

 

[Taylortwocities]

One thing I was thinking is if they change the location of anything surely it would be easier and safer to relocate the meter nearer to the main fuse?

Yes it would but you are looking a fair bit of dosh for that to be done.
You'll need a quote from your electric supplier and be prepared to wait some months!

 

[flameport]

Test equipment can be hired for a short period
e.g: http://isswww.co.uk/hire_products.php?cPath=219

Far cheaper than buying for a single job.

 

[MisterG]

Am I right in saying that all burried cables that are less than 50mm must either be in protective trunking or protected by a 30ma RCD?

Hi, yes that's right. BTW, protective trunking is made of steel, not the plastic stuff.

IMO, it's probably easier to go down the RCD route.

Also the diagram for areas to run cables seems to be quite restrictive I think im interpreting it wrong. Can I run cables anywhere in the wall provided they are outside of the 150mm safe zones and are run on horizontal/vertical planes?

Not sure what you mean here, it's called a safe zone becuase that's where someone would expect cables to be. If you run them anywhere then the next owner of the propoerty will likely put a nail into the cable.

This is quite a big job, I was planning doing something similar, as I needed to rewire all the light cuicuits and need a new CU. After investigating all that was involved, I ended up paying an electrician to do the bulk of it. I was amazed at how little mess they made, compared to what I would have done.

 

[electronicsuk]

Am I right in saying that all burried cables that are less than 50mm must either be in protective trunking or protected by a 30ma RCD?

Yes, that's correct, although 'protective trunking', as you call it (presumably you mean earthed metal ducting or conduit) is not the only way to avoid using RCD protection. You have other options such as Steel Wire Armoured, Pyro and FP200-esque foil shielded cables, or mechanical protection via a suitably thick steel plate. However, the norm is still T+E <50mm deep with RCD protection, unless you have good reason not to want a circuit to be RCD protected.

Also the diagram for areas to run cables seems to be quite restrictive I think im interpreting it wrong. Can I run cables anywhere in the wall provided they are outside of the 150mm safe zones and are run on horizontal/vertical planes?

I think you may be confusing yourself. An electrical accessory on the wall will create safe zones on the wall both vertically and horizontally inline with itself, in which you can run cables with no need for mechanical protection/armour/etc. However, as they will almost certainly be less than 50mm deep, RCD protection is still required.

There are additional safe zones created by internal corners and ceilings in which you may run cables if you wish, even without the need for an accessory on the wall to indicate a cable's presence.

If im attaching cabling to a ceiling joist which will then be covered with insulation am I best running this inside trunking due to the amperage drop from 20 down to 13?

You'd be best trying to avoid the insulation full stop.

 

[barcelona]

What is the correct procedure for lighting circuits in loft areas under insulation?

You see this illustrates the problem. You can't learn what you need to know just by asking whatever questions happen to occur to you, and people here can't teach you what you need to know via unprompted posts.

Have a read through all of these, and see what you think about your chances of becoming competent - only you can tell how much you already know, and how much sense the things you're encountering for the first time make to you - the first 3 you'll have to buy, but the others you can start reading online while you wait for the package from Amazon.

• http://www.amazon.co.uk/exec/obidos/ASIN/0863418546
• http://www.amazon.co.uk/exec/obidos/ASIN/0863418627
• http://www.amazon.co.uk/exec/obidos/ASIN/0953788555
  
• http://web.archive.org/web/20080213151445/http://www.kevinboone.com/domesticinstallations.html
• http://web.archive.org/web/20080213151445/http://www.kevinboone.com/cableselection_web.pdf
• http://www.tlc-direct.co.uk/Book/1.1.htm[/list]
  
  
  

  What kind of fee would I be looking at paying to have it inspected/registered?

  Only your council can tell you that, and if your username here is accurate they'll be one of the ones who effectively won't let you do it.

• Just read those online articles. Very informative. Thanks.

 

[unlucky]

Another question for your expert eyes!

Is there a restrictive length on the tails out of the meter to the CU? with planning on keeping the existing electrics in place until the new ones have been inspected, tested and certified I am going to need to locate the CU in a different location to the existing one.

So I'm wanting to know how close I have to locate it!

I know what you mean about it taking months to swap out the old main fuse, the meter replacement company said it would be the new year before it got done!!

As far as the cost of provisioning/relocating the meter surely this would be the responsibility of the meter company?

In your opinions would running the livingroom and kitchen-diner off separate circuits for the plugs be a little excessive? Livingroom will have;

TV,
DVD Player,
PC,
PS2,3
Wii,
Sky Box,
Stereo
Router
Modem
Macbook charger
and other chargers, but not plugged in full time.

Kitchen-diner;

Washing Machine,
Cooker (although this is 13amp will probably put on a seperate 32amp circuit to futureproof it)
Dishwasher
Fridge/freezer,
Microwave,
Kettle,
Toaster.

Thanks for your continued help and advice.

 

[flameport]

Is there a restrictive length on the tails out of the meter to the CU?

Yes, 3 meters is typical but some DNOs have other requirements. Check with them before deciding on the position of the CU.

As far as the cost of provisioning/relocating the meter surely this would be the responsibility of the meter company?

No. You are responsible for the entire cost, £500 or more would not be unusual. It is also likely they will only move the meter to an outside wall in a box as found on new houses. If so, you have to pay for the box and installation of it as well.

In your opinions would running the livingroom and kitchen-diner off separate circuits for the plugs be a little excessive?

All that living room stuff uses very little power.
The kitchen appliances will use plenty, so it is sensible to provide a separate circuit for the kitchen.