New domestic installer help please

[Tucosweep]

Hi,
I'm a newly qualified domestic installer and I need some help with my next job please.
My customer wants 15 double sockets installed in a small bedroom for his music mixing equipment and computer and guitar amps ect..
I was going to install a new ring circuit solely for the studio and I'm upgrading cu with split load RCD at the same time.
Is there anything I need to be aware installing that many sockets in one room or will it be a straight forward new circuit install?
The property is a mobile home.
Any tips or help will be appreciated
Thanks

 

[malcolmsanford]

Hi and welcome.

1. That many sockets on a single circuit is poor design to be honest, if you loose a socket you loose them all, split them,
2. Are you able to change the CU in a caravan/mobile home
3 How is this mobile home/caravan supplied ie is there enough power for these additional sockets
4. How mobile is it
5 What is your earth system
6 Have you read section 721 and installations in mobile homes
7 Is there SELV circuits in it can be compromised by this music equipment
8 Have you taken into account any functional earthing that might be required for this set up
9 ADS in this set will need DP RCD
10 Your overcurrent protection also needs to be DP
11.You need to install notices outlining your work
12 Your wiring needs to be of the relevant BS standard ie BS 60332-1-2 as a minimum
13. You have to take care of your routing only certain voltage levels are allowed in certain areas
14. There are special consideration for containment regarding fixing
15. You have to separate all voltage bands


And that is just the start

 

[telectrix]

in general, you would put a max. of 10 d/sockets on 1 circuit, but as the loading is going to be light, you should be OK.
if you are installing a new CU, my preference would be 2 16A radials. split it up into 2 circuits. as it's a mobile home, pay particular attention to the earthing.some of these sites are diabolical. if it's TT then i would be tempted to fit an upfront 100mA RCD.

 

[Tucosweep]

Thanks,
That's alot to consider,
The mobile home is a park home and not a tin static caravan, it currently has a rewirable fuse board.
I haven't designed the circuit yet and will get a complete list of equipment being used to determine the load value,
Will I need to use extra earthing because of the equipment being used?

 

[Tucosweep]

Thanks
Telectrix

 

[J&M Electrical]

Some of the more experienced older heads might disagree with this but you might also want to consider using clean earth's for the ring as it will be having computer/sensitive equipment on it. Not 100% sure what a clean earth does but i can remember when i was serving my apprenticeship we wired our new company offices and the sparky at the time said we had to do it for circuits that will be used for computers. I'm gonna go look it up now actually

 

[Andy 7671]

+1 on researching clean earths. There was a thread about earthing a mixing desc for interference reasons, the practical solution was to take it straight to the electrode.

Is he going to put up soundproofing which would derate current carrying capacity...?

 

[Tucosweep]

Thanks for the input so far guys,

I will also research clean earths.

There won't be any sound proofing as its a very simple studio set up,
The customer has been using multiple extension leads for some time with no problem, no RCD either has it happens.

Going in next week to do some initial testing, do you know of a good way to run the cables in a park home without to much distruction?

 

[Adam W]

Park homes don't seem to be built with alterations in mind, so I'd probably run the cables in surface trunking, maybe even the sockets in dado trunking.

 

[SPARTYKUS]

There might be a few problems AFTER the Rcd goes live!


And maybe not....

 

[WDMDL]

You'd be fine with a 20A radial for the expected loading tbh.
You may consider two circuits though, one for audio equipment and one for computer equipment.
You could possibly identify one from the other using coloured sockets, or for example the ones that have red rocker switches.
For a permanent studio setup, your idea of installing dado trunking fits the bill perfectly, as it's then easy to modify later.
You could run the cables between the dado trunking and CU in conduit, underneath if the studio is not adjacent to the room with the CU.
There may be no need for a clean earth, most audio equipment is class II these days - there were far too many "ground loop" problems with Class I equipment... the Musician's fix was to chop the earth off in the plug.
Balanced audio interconnects also help avoid these problems.

Remember, for the purposes of BS7671, a static caravan is treated just the same way as a house.

Simon.

 

[Tucosweep]

Thanks Simon