Tv electrical point

[Diyer101]

Hi, I'm helping a friend to wall mount his tv. It on an external wall. To avoid making holes on the inside we thought of running the through a hole onto the outside and routing it to where he wants the internal socket for the tv and then bringing it backbinside through a hole. The wire would exit from a fused spur and all holes would be sealed. Is this a legal instalation? And would be ok to diy or would it be subject to part p because we route the wire outdoors?
Any comments / advise much appreciated.

 

[PrenticeBoyofDerry]

Not illegal or notifiable providing no external joints are made, but when extending circuits tests should be taken using specialised equipment.
The cable should be suitably protected for the outdoor environment.
ie. protected for mechanical damage, extreme weather conditions, rodents and plant growth.
So you would either need to run a cable that has mechanical protection already in-cooperated within it, something like Steel wired armoured(SWA) or mineral insulated, the latter is harder to terminate and for SWA will need a gland pack. The other option would be to run the cable in conduit.
The use of the standard grey PVC twin & earth is not recommended, as it does not have mechanical protection or like extreme frosts or direct sunlight and easily chewed by rodents.
PS every domestic installation is subject to part p, it's a building regulation that must be complied to, regardless of whether it's notifiable or non-notifiable work.
Does the circuit you are using for the spur have RCD protection?

 

[Diyer101]

Hi there, thanks very much for the reply. We're planning on tapping the fused spur from a plug socket on the ground floor ring. I believe the ring is protected by an Mcb at the fuse box and the particular circuit protected by an rcd in the box. Havnt checked the rating of the mcb but was going to use a 3 amp fuse in the spur. Does this sound about right? I havnt ever tested a socket instalation before as I'm a diyer and do this infrequently however, im keen to improve my knowledge in this area. What kind of checks do I need to make? Not worried about getting the equipment as it would be a good investment for the future incase I do this this again.

 

[PrenticeBoyofDerry]

Use a 13A FCU, the plug on the appliance/appliances will/should offer any additional reduction in fuse rating needed.
The equipment used are quite expensive and if it is for DIY purpose, would not be financially a good investment.
You can hire them though.
The test that should be carried out for minor works are as follows;
Earth continuity
Insulation Resistance-(line/neutral, line/earth, earth/neutral)
Earth fault loop impedance
Polarity
RCD
A minor works cert should also be filled in.
You can find downloads here, you are wanting the BS7671:2008 forms
http://electrical.theiet.org/wiring-regulations/forms/index.cfm.
It is not a straight forward job, installing extra sockets, though many do not carry out the correct procedures when doing so and ignore the tests and certification

 

[ban-all-sheds]

http://www.tlc-direct.co.uk/Book/8.1.1.htm

 

[ericmark]

It is unlikely that any "ordinary person" will do electrical work and comply with the regulations. However "skilled persons" and "competent persons" also do work in their own homes which is of course classed as DIY. As already said the meters cost typically around £750 to buy and £75 to hire for minimum period of a week.

Even if the "ordinary person" had these tools there are some dangers in using them and I would be the last to advise "ordinary persons" to use them.

However we all know the "ordinary person" will attempt to do DIY and there are some things that can be done to minimise the risks.

These

are not really a replacement for the expensive meters but it will reduce the risk and at £35 it does not break the bank.

The cheaper types

start at around £12 but of course there is VAT on these prices.

It all comes down to a risk assessment and do you think it is worth the risk. Around 1990 I decided not having RCD's on all circuits was not worth the risk and I fitted them. There was no obvious gain in fact more than once they tripped out and I then also fitted emergency lights on landing and garage (where the RCD's are).

However my son did decide to become a Radio Ham at 14 years old and had I not fitted RCD's I may not have had a grandson now. But I will never know if the RCD which he did trip a few times really saved him or not.

I have nothing against DIY but one has to consider the risks. My father-in-law has never fitted RCD's and as he says he does not intend to do anything which will give him a shock. But he and me plus my son are now all electrical engineers and we understand the risks.

So think about it. From what you say you have no RCD protection, you by very fact you are asking the question are only a "ordinary person" who may at a stretch be an "instructed person" do you think on making an assessment it is worth the risk you get something wrong?