Study Sockets

[adamr7747]

Hi All,

I'm planning on converting a (small) room into a study. I'd like to provide plenty of sockets on the ring - at least 5 doubles along the wall under where the desk will be. Is there anything in particular to take into account? Specifically, I'm wondering about surge protection (e.g. from lightning strikes to the grid/telephone wires?) to protect the family photos etc and also vaguely about DC outlets - is this a sensible thing to cater for? I have loads of "bricks" around the place but am unsure how to go about getting rid of them.

Thanks a lot for any thoughts/advice

Adam

 

[riveralt]

Hi All,

I'm planning on converting a (small) room into a study. I'd like to provide plenty of sockets on the ring - at least 5 doubles along the wall under where the desk will be. Is there anything in particular to take into account? Specifically, I'm wondering about surge protection (e.g. from lightning strikes to the grid/telephone wires?) to protect the family photos etc and also vaguely about DC outlets - is this a sensible thing to cater for? I have loads of "bricks" around the place but am unsure how to go about getting rid of them.

Firstly you should inform your Local Authority Building Control of your plans - pay their fee and advise them how you intend to certify that the installation meets the necessary test criteria.
You will have already done this for the other rooms you have rewired so it shouldn't be a problem. Although it does seem strange that you are paying out twice or three times for LABC authority when it would have been easier to include the lot on one application.
In terms of your sockets you will need to determine you maximum demand before you go deciding what type of circuit to install, how it will be protected, what size cable and what size overcurrent device you need to use.
You will also need to take into account voltage drop, cable runs and safe zones as well as any environmental and or insulation issues.
Some LABC's will assist you in this process some wont. You will proberly know whether you will get such assistance from your previous experience with them.
As for DC outlets - no sure why you would need them since computers operate at AC - As for surge protection - seems to be mainly linked to extension sockets rather than individual sockets.

 

[ericmark]

There are both skirting and dado trunking and power track systems that can be used to take power and data cables and are used quite often in an office environment. However the cost normally means these are not used in domestic buildings.

There are things to reduce electric storm damage and if you look inside the master telephone socket it does contain spark gap and leakage resistors also storage capacitors for the bell. There are surge protection devices but as to if really required is another thing.

Most computers run on a switched mode power supply. This works by converting the power to DC and charging a capacitor then turning it back to AC at a high frequency then turning back into DC and smoothing the output. The chance of any spike getting through that is very small so can't see why people used surge protection for computer supplies. The problem is more to do with the filters already installed in the power supply to stop spikes caused by the power supply from getting back into the system. These filters often have a connection to earth and have a small amount of leakage this with multiple devices can mount up and trip the RCD. Only real cure is multiple RCD's so there is a limit to how many devices run through same RCD.

The surge protection sockets have renewable filters as they have a limited life span. Personally I would only fit them with overhead supply lines and of course there needs to be a maintenance plan to change them at the prescribed time and ensure one knows where they all are so they can be removed before testing.

 

[Chri5]

Since at a later stage in the homes life the study might revert to a bedroom I'd avoid peppering the whole room with sockets.

Since the room is critical I'd consider a direct 2.5mm 20 amp radial from the CU on its own rcbo. 20 amp / 30mA trip. That will prevent issues with a general house rcd trip affecting the study.

Wall warts are a pita, but it really can't be covered by an all size dc supply, since wall warts have different voltages and different output design for the equipment they are married to.

A good under desk solution is a power strip and lead of the type used in data racks. They come in all sizes from 7w to 13w and can be wall mounted or mounted on the underside of the desk. The max load is 13 amp as a plugged device, but then again a typical load for a few pc's- mobiles -printer - iPad etc will not be more than 13 amp.

 

[bernardgreen]

Surface mounted sockets on 4 by 1 timber and supplied from a FCU or a 13 plug in socket is one way to do it. It suited the wall construction of my work room to do it is 2 foot long sections.

Untitled

• bernardgreen
• 27 Mar 2009
• 3

or use larger timber and flush mount the sockets

or this from Olson

http://www.olson.co.uk/13amp_slim.htm

 

[TonyW2]

//www.diynot.com/network/TonyW2/albums/3222
This was my solution after my first posting on thid forum.
The double socket is part of the ring and the rest is run as a spur via the fused unit and two gang switch.
Can't see any need to involve LABC.

 

[bernardgreen]

By not using the 13 Amp plug the sockets could be seen as being a new part of the permanent wiring and thus possibly notifiable. My preference is for the 13 amp plug as this enables all bench top equipment to be fully isolated when not in use. Removes ( reduces ) the risks of earth loops of the sort are detrimental to the operation of some equipment.

 

[TonyW2]

Why would a spurred addition to a ring in a study or bedroom be notifiable?

 

[RF Lighting]

It isn't.

 

[ban-all-sheds]

And even it it were that would have nothing to do with whether a plug was used or not.

By not using the 13 Amp plug the sockets could be seen as being a new part of the permanent wiring and thus possibly notifiable.

Bernard - this theory has been raised many times in the past, and the answer is always the same.

The scope of Part P is fixed wiring - the regulations make no mention of, and draw no distinctions involving, permanent/temporary. If you fix sockets to the wall then they are fixed, whether they are supplied via surface flex to a plug, surface flex to an FCU, or buried T/E back to the CU, and are therefore within the scope of Part P.

 

[adamr7747]

Most computers run on a switched mode power supply. This works by converting the power to DC and charging a capacitor then turning it back to AC at a high frequency then turning back into DC and smoothing the output. The chance of any spike getting through that is very small so can't see why people used surge protection for computer supplies.

Thanks, that's interesting.

The surge protection sockets have renewable filters as they have a limited life span. Personally I would only fit them with overhead supply lines[...]

We do have overhead supply. But if you said above that computers aren't susceptible to lightening spikes etc, then presumably there's no need for surge protection even then?


Thanks for the other replies. I guess all-in-all it makes more sense just to go with some wall-mounted extension blocks of some kind.

Adam

 

[adamr7747]

[snip long, seemingly off-topic and petty rant]

Sorry if I've upset you in some way, but your post comes across as kind-of nasty/condescending and frankly misleading.

As for DC outlets - no sure why you would need them since computers operate at AC - As for surge protection - seems to be mainly linked to extension sockets rather than individual sockets.

And you didn't even have anything useful to say. All in all, I feel like the world would just have been a slightly nicer place if you hadn't pressed "submit"

Adam

 

[bernardgreen]

If you fix sockets to the wall then they are fixed, whether they are supplied via surface flex to a plug, surface flex to an FCU, or buried T/E back to the CU, and are therefore within the scope of Part P.

Which would mean that an extension lead would be notifiable if it was "fixed" in any way. Such as is possible with the keyholes on the rear for hanging ( fixed ? ) the lead's socket(s) onto a pair of screw heads.

Computor power supplies with pre-regulation can be susceptible to large spikes on the mains from large motors starting up but in the domestic situation that is unlikely.

 

[ban-all-sheds]

Which would mean that an extension lead would be notifiable if it was "fixed" in any way.

No - it would mean that it would be WITHIN THE SCOPE OF PART P.

It would not necessarily be NOTIFIABLE.

This is something else which has been endlessly covered here - are you never going to get it?

 

[riveralt]

[snip long, seemingly off-topic and petty rant]

Sorry if I've upset you in some way, but your post comes across as kind-of nasty/condescending and frankly misleading.

Unsure why you would take it that way - there is nothing misleading in what I have said. If you intend to introduce a new circuit into your property you have to do the calculations and conduct the appropriate tests.
Furthermore, introducing a ring final circuit or any additional circuit into your home requires notification - I simply pointed out that since you had/where already rewiring another room as per
//www.diynot.com/forums/electr...d-mechanical-protection-or-no.315049/#2320447
you would have already have notified your Local Authority Building Control and I couldn't understand why you didn't save money by submitting one application rather than two. After all you did submit an application for the first rewire - didn't you?

And you didn't even have anything useful to say. All in all, I feel like the world would just have been a slightly nicer place if you hadn't pressed "submit"
Adam

Just because someone highlights what you must do when carrying out diy work rather than what you would like to do, has nothing to do with making a 'slightly nicer place', it has more to do with making a slightly safer place - if you choose to ignore such advice then carry on - you're the one possibly putting yourself and others in danger not me.