Unswitched Fused Spur

[john2k]

I want to spur off a existing mains socket to one of these unswitched fused spurs:

https://www.screwfix.com/p/schneider-electric-lisse-13a-unswitched-fused-connection-unit-white/6916j

And then from this fused unit I want to fit it with a 3A fuse and run it to a USB power block which I will leave inside the cavity of the drywall. My question is from the mains socket to this unswitched spur can I run a 1mm or 1.5mm cable or does the cable have to be 2.5mm? Is it dependent on the load that the unswitched spur will supply?

 

[blup]

I would think 1.5mm is the minimum because that is rated at 13A but I suspect many pro electricians would fit 2.5mm.

Blup

 

[Adam_151]

2.5 to feed the spur, then 1mm after the spur. But please dont bury USB power supply units in stud walls! (or any other kind of wall!)

 

[AndyPRK]

can't you use a USB 13A socket

single or double.
Some have 3 socket outlets now. (screwfix)

 

[john2k]

2.5 to feed the spur, then 1mm after the spur. But please dont bury USB power supply units in stud walls! (or any other kind of wall!)

Any particular reason? I'm installing a tablet into the wall with a recess mount. At the bottom of that dry wall is a socket. But to keep the install looking clean I don't want to have an external plug going into the wall. So I wanted to plus the usb power supply into a wireable socket running off the unswitched spur. I want the tablet to charge for few hours twice a day and so what I was thinking is to run the usb power socket through one of those digital timer sockets

 

[bernardgreen]

please dont bury USB power supply units in stud walls!

Any particular reason?

Air flow around the power supply unit may be necessary for cooling.

If the power supply unit does start to show signs of serious ( and hazardous ) overheating then you may not notice until too late.

 

[AndyPRK]

so you could replace your existing socket with a USB one.

Run a USB cable down and inside the wall to look neat. and have it appear next to the 13a socket

 

[john2k]

can't you use a USB 13A socket

single or double.
Some have 3 socket outlets now. (screwfix)

For me to use those means the usb wire has to be plugged in from the front. Which means the wire comes down the cavity then out and then from the front plugged in. This doesn't look that great. If those sockets had a usb connection from the back that would be great.

Plus I want to run the usb power on those digital timers. I'm guessing burying the digital timers is also not a good idea?

I was planning to keep the usb power block and the timer right under the tablet mount so I can from time to time just pull out the tablet and inspect the timer and usb plug

 

[john2k]

so you could replace your existing socket with a USB one.

Run a USB cable down and inside the wall to look neat. and have it appear next to the 13a socket

Instead of spurring a unswitched spur going from mains 2g socket, can I just spur the following item:

https://www.toolstation.com/greenbrook-7-day-electronic-wall-switch-timer/p16578

This will remove the need for me to put the timer plug inside the wall cavity. And then from this unit if I run a flex cable to a wireable socket just behind the tablet recess so that the tablet usb block is literally right behind the tablet and since the tablet comes off easily, it makes accessing the usb plug block easy and seeing as the power will only be time for about 3 to 4 hours twice a day then technically the usb plug isn't on always. The other way the worry is although the usb isn't always on, the digital timer is

 

[AndyPRK]

i'm not sure if that is acceptable or not.

I would be happier if the timer had a fuse in it

e.g

https://www.ebay.co.uk/itm/24-hour-...360674?hash=item4691889f22:g:6A8AAOSwzMlcgnHT

 

[oldbutnotdead]

Don't think it would comply (that timer is designed for lighting circuits) plus it won't run your charger properly- minimum load 40w resistive. Those light switch replacements usually have no neutral & run by trickling current through the lightbulb. If your power supply was an actual wirewound transformer then it might work...but all those cheapies are switch mode of some sort so highly unlikely to work.
EDIT AndyPRK's suggestion would comply but again might not power your usb block properly- if it switches via a relay then fine, if it uses triac/thyristor/SSR then not fine. Check the specs