Wiring networking gear into lighting circuit?

[Lobster]

I'm currently planning a bit of a rejig of my home network, to suit changing circumstances, which means re-siting some of my kit to a new location, probably a ceiling-height shelf located in a walk-in 'open' cupboard off the hall. This will include my cable modem, wi-fi router, a network switch and a VOIP wireless base-station.

Looks like the most awkward part will be getting mains power to these devices, all of which of course have their own wall wart. It struck me that by far the 'easiest' solution to achieve this would be to take feed off the downstairs lighting circuit, and was wondering whether this would be a tenable option under the circumstances?

What I'd propose would be to fit a clearly labelled 5A FCU at ceiling height, to which would be hardwired a standard 4-way extension block on a short flex (ie, so it would only be able to sit on the ceiling-level shelf), into which I would plug the four wall-warts (total load no more than 100W maybe?).

Comments please?

Thanks David

[Tim]

It may not be best practice, it may not meet regulation. Sounds like you know what you are doing though. At the end of the day it's your house (not the Governments) so go ahead.......

[Tim Watts]

Dave Liquorice wibbled on Tuesday 30 March 2010 10:10

And I would use a non standard socket (eg 5A round pin) to disuade some future visitor or the next owner from uprating the FCU fuse and plugging in a fan heater. Mark teh FCU as "MAX 3A Fuse" or something.

[Lobster]

No, an open cupboard - it used to be a closed 'under-the-stairs' type one, but I removed the door and incorporated it into the hall as a 'walk-in' coat-hanging area. So really no problem as regards heat.

Thanks for the fuse suggestion.

Yeah, point taken. The fact that the sockets will be at ceiling height above a shelf will hopefully dissuade that; and certainly it's not a wiring arrangement I would ever consider leaving in place after selling the house ;-)

David

[Dave Liquorice]

B-)

The lighting circuit may only be protected to 6A so I'd put the smallest fuse I could in the FCU. 1A used to be available, that's still over 200W ample for four wall wart powered devices. If this is a "sealed" cupboard think about ventilation for cooling some wall warts and kit runs quite warm even in the open, think summer with ambient temp 30C and the kit running say 20C above ambient, thats 50C starting to get close to this sort of kits maximum temp.

[Dave Plowman (News)]

Instead of a FCU I'd fit a 5 amp three pin socket, and plug your 13 amp extension block into that. No need for a local fuse as the MCB will protect all the wiring. But you could get extension blocks which take fuses if you want.

[cynic]

Possibly you should consider the reliability of supply. Lighting circuits sometimes trip when a lamp fails whereas a 30 or 32A device protecting a ring final circuit may never trip once during its lifetime.

[Andrew May]

Surely nowadays the opposite it true. A lighting circuit may not even be on an RCB but a ring is likely to be and is likely to trip whenever someone does something the tiniest bit silly like pushing an electric mower into a wet bush and shorting out the motor windings.

Andrew

[Tim Watts]

Dave Liquorice wibbled on Tuesday 30 March 2010 13:46

It wouldn't until the OP sells the house, then it would.

Until then, it would make it pretty obvious that the supply was weird.

[Dave Liquorice]

How would that stop some one plugging into the 13A sockets fed from this 5A round pin that the wall warts want?

[John Rumm]

There is nothing intrinsically wrong with powering "other" things from lighting circuits (its routinely done for fans, shaver sockets, towel rails etc).

I would probably install a socket of some sort - its location and labelling should make clear its purpose. Even you use a normal 13A socket, then even if someone does plug in a fan heater, all that will happen is the circuit fuse will blow/breaker will trip.

I would also be tempted to use a small UPS if protecting the supply to the shelf if there are cases where this might prove useful.

[Dave Liquorice]

disuade

from

Bear in mind this round pin is 5A rated and unfused, most lighting circuits are protected by a 6A MCB these days... I still think a FCU (SFCU) with 3A fuse is the better bet.

[Mike Clarke]

It's not a RCD issue but a matter of lamp bulbs taking out a 6A MCB when they burn out. Though it will become less of an issue with the move over to CFL's, except for those of us who took steps to stockpile good old tungsten filament bulbs.

[Andrew May]

I've never had an incandescent bulb blow a MCB but have on several occasions had an RCB trip because of a fault or user stupidity.

With MCBs replacing wired fuses I suspect that that will become increasingly common.

Andrew

[js.b1]

Location is off the hall, near ceiling height... unless this is a bungalow there must be a 20A radial or 32A ring cable within the range of a 300mm-screw-together cable access rods + magnet + metal bath- chain?

[Lobster]

Well fair comment - I'm not saying that would be completely impossible; just know it would be very awkward from prior experience, eg due to positioning of ceiling joists and HW cylinder in the area immediately above where I want the power. I'm certainly not ruling that out; just looking at all my options.

Thanks David

[js.b1]

That can indeed make things very difficult.

What is the other side of the cupboard downstairs? Is there a socket nearby you can bring into the cupboard, then up the wall behind D-Line trunking or similar. If your walls are old plaster-skim over browning (sand!) you can go about 1m along behind the plaster skim to a nearby socket in the room behind (takes a few hours & blisters on blisters) - if modern plaster it's impossible tho.

[NT]

A 2A or 5A round pin socket on the lighting circuit is fully compliant.

An fcu is not needed and really its pointless. Under any real life fault conditions the circuit MCB will trip before a thermal fuse. There's no safety advantage to 2 overcurrent trips in series.

NT

[Steve Walker]

Yeah, it'll be fine.

[Fredxx]

Only further comment I would make above others before, is that I thought outlets required an RCD. So your lighting circuit ought to be on a RCD if it's not already.