Which size SWA for a 40 metre run into music room?

[Big_Spark]

Beanzy, at the supply end you fit a 500mA 40A Type C time delayed RCD, this will protect the cable, and the installation involved.

At the garage end, the power to the Amps I would supply via a Type C MCB if the inrush currents are high, however in my experience this is not the case, so would settle for a Type B.

It would be wise to seperate the circuits though and have two or three 16 or 20A rated circuits.

I think people often forget that the Garage MUST be RCD protected, but that electronic equipment often results in nuisance tripping, hence the high fault current and time delay.

 

[Beanzy]

Beanzy, at the supply end you fit a 500mA 40A Type C time delayed RCD, this will protect the cable, and the installation involved.

RCD? This is why I'm confused surely RCBO to protect the cable too?

 

[Deluks]

OK, lots of info to digest here and you don't seem to agree 100% but I guess that's a mixture of knowledge and opinion

So to clear a few things up,

:The room will only be 10ftx12ft, and will have rockwool buried in the walls and ceiling, plus a double carpeted floor (over painted concrete) I don't think it will get too cold in there and if it does, I'll just run an oil filled rad or similar for a while before jamming to take the chill off the air. So heating and guitar amps won't be running at the same time.

:Mixed opinions on using fluorescent lighting, but this won't be in the music room, just in the main part of the garage, although will be on the same 6a mcb as the lights in the music room. Will this still affect the amps? and what are these 'High Frequency Control Gear Fluorescent luminaires'


:The room will be primarily for rehearsal, although I would like to keep a PC in there for basic multitrack recording/demoing songs.

:I'd automatically assumed I'd be using 3 core SWA, if that's not the case, what are the disadvantages of using 2 core?

:As it looks like 10mm might have to be the way to go, how thick is this stuff anyway, as I have quantity of 20/25mm pvc pipe that I was intending to run the cable through for extra protection. and how deep does the trench have to be, is there a minimum depth for burying this stuff? (I'll need to know as this is one job I will definitely be doing myself!)

thanks again! (again)

 

[ban-all-sheds]

what are these 'High Frequency Control Gear Fluorescent luminaires'

http://www.flg.co.uk/faq_info/high_frequency_faq.htm
http://uk.altavista.com/web/results...tf8&q=+"high+frequency"++control++fluorescent

:I'd automatically assumed I'd be using 3 core SWA, if that's not the case, what are the disadvantages of using 2 core?

1)Difficulty of ensuring that you get a good enough connection to the armour when you terminate it for it to be safe as a cpc.
2)Depending on the size of the cable the armour may simply not be large enough to be used as the cpc.

:As it looks like 10mm might have to be the way to go, how thick is this stuff anyway,

18-20mm O/D

as I have quantity of 20/25mm pvc pipe that I was intending to run the cable through for extra protection.

A bit tight..

and how deep does the trench have to be, is there a minimum depth for burying this stuff? (I'll need to know as this is one job I will definitely be doing myself!)

The regs say it should be deep enough to avoid being damaged by any disturbance of the ground reasonably likely to occur. See this http://www.tlc-direct.co.uk/Book/7.13.3.htm for some useful guidance...

 

[Lectrician]

What colour is your 'piping' (duct)? If black, thats fine. Any other colour is not complient.

 

[ban-all-sheds]

I think that's only NJUG guidance for ducts etc laid in the street..

 

[Deluks]

Does anyone here know roughly how much power a guitar amp uses? I've got a 12" speaker combo bass amp, all the relevant info had faded from the back so I've no idea what it uses. My guitarist uses a marshall half stack, anyone know what they run on?
May also get a small PA amp in the future to run alongside these two.

Adding computer, lights, small oil filled rad in winter/couple of fans in summer, what kind of power will that lot need?

cheers
Deluks

 

[mapj1]

If each unit plugs into a 13A socket, then a look at the fuse in the plug will give you an upper limit. Probably no more than 5A a piece, a kilowatt is a lot of sound. (it could just have a 13 A fuse just because one was to hand of course.)
Noddy test -can you plug all these things into one 4 way extension lead without the fuse failing in the first 5 minutes? If so its less than 13 A total(well less than 20 A anyway... actually a cold 13A fuse will take 20 A for a few mins without failing.)

If you said a max load of 20A for the sockets, and allowed 32A to be safe, plus 6A for the lights, I'd be surprised if you saw nuiscence tripping problems.

M.

 

[Beanzy]

As a guide : Peavey;

Guitar amps per unit;
212J
150 watts @ 8 ohms peak 600 Watts

412JS
280 watts @ 8 ohms peak 1200 Watts

PA stuff per cab.
UL 15
500 Watts RMS continuous, 1000 Watts program, 2000 Watts peak into
4 or 8 Ohms

UL 215S
1000 Watts RMS continuous, 2000 Watts program, 4000 Watts peak into 4 Ohms

Depends what the max you'll want to run in there would be, but if you get the RMS value then the rule of thumb they seem to use is x3 or x4 for peak. And allow for the effects of the resistance on the supply, prob best to de-rate as per other inductive loads (1.8) that's supposed to be one point eight but the smiley came up .

 

[maltaron]

When I was a sound engineer we never dropped the earth in an XLR, allways used ISO boxes with switched earths to enable everything to be earthed but broke the loop. In this setup there are unlikely to be XLRs, more likely jacks and unbalanced - dropping the earth can be lethal.

 

[Spark123]

Seen the date of the O/P