Installing LED stip lights above cabinets

[pmxcrw]

Hi,

I'm looking for some advice on installing LED strip lights above and below some cabinets and bookcases in my living room.

Once installed, I'll have a run of ikea besta cabinets, wall mounted, about 15cm off floor level, and another set of cabinets about 20cm below the ceiling level. TV is wall mounted in between. I'll also have a third set at the opposite corner of the room forming a set of bookcases.

I want to have 4 sets of LED lights, one below the bottom cabinets, one above the upper cabinets, one behind the TV and one above the bookcases.

Looking for advice on how to safely install cables. At the moment we've moved out of the property (a new build) because of issues with floors and joists, so the ceilings have all been pulled down by the developer so I have a window where I can easily run cable in the ceiling cavity.

My plan was:

1) There's a double socket that will be inside the bottom cabinets once installed. One of these sockets I'll use a 6 gang extension to power the TV, media PC, music amp etc (that are all housed in these cabinets). The other socket I was planning on installing this power supply to drive all 4 LED strips (which are 12V DC, 9.6 watts per meter):

https://www.led-lighthouse.co.uk/le...-well-100-watt-led-driver-12v-ip67-lpv-100-12

The total length of the LED strips is 9m, and it's rated at 9.6 watts per meter so this seems to be a safe choice.

2) Coming off this I'd use the following Z-wave switch so that I can control the 4 LED strips independently

http://www.vesternet.com/z-wave-fib...=a6976d84f3ed41006dffad179bb809da&fo_s=gplauk

Each of the 4 channels will handle 6A indpendently, and the unit will handle 12A in total. The maximum length of the 4 LED strips is 2.4 meters, and total length is 9 meters so I'm within both of these limits (12V, 9.6 watts per meter = 0.8 A per meter).

3) I've bought 1.5mm twin and earth to run the 12V power from this to the three strips that are close to the switch. These runs will all be short so the voltage drop is minimal. I've also bought 14 meters of 4mm twin and earth to span from the Z-wave switch, across to the bookcase in the opposite corner. Plan was to

What I need some advice on is:

A) How to connect the LED driver into the mains. It's an "in line" unit, so is it OK to just fit a plug and use the existing sockets, or do I need to add a switched fused spur (and if so, how do I get the cable out from behind the cover on the spur and into the cupboard?)

B) The walls are dot and dab, and seem to have plenty of room for fishing cable behind (I've already installed some brush wallplates and fished HDMI, Cat 6 and speaker cable behind the walls where needed). But is it safe, and compliant with building regs to do the same for the 12V cable used to power the LED strips? Horizontal runs would be within the cabinets, but I need to pass cable vertically behind the plasterboard to avoid it being visible.

Likewise, in order to reach the bookcase in the opposite corner I need to run the 4mm2 twin and earth across the ceiling cavity. There's already a lot of power cable running up there, and the joists are pre-drilled, so this seems simple enough.

The existing switches are fed by running cable along the ceiling and down behind the dot-and-dab, so I'd largely just be reversing this, running my new cable adjacent to the existing cables. I'd need to come back down the wall behind the bookcase, but only for 20cm or so, and there's another socket behind the bookcase so I'd be running my cable down adjacent to existing 240V cable.

Everything makes sense in my head - but my main worry is doing something that my plan breaks building regs? I've got limited time before the builders are ready to reboard the ceilings - so if someone would be kind enough to give me some advice I'd be very greatful.

Many thanks.

 

[RF Lighting]

Don't plug the lights on. That's an awful idea.

You've got a perfect opportunity to do the job properly. Have them switched on and off at the normal light switch.

Run mains to each block of cabinets and site a driver on the top of each block of cabinets.

Take your cable back and get a refund it's all far too big. You need 1.0mm² for the mains supplies, and then some 0.75mm² two core flex to link from the driver to the LED strip.

 

[ban-all-sheds]

He bought a bit of cable cut to length.

Chances of a refund pretty low, I would think.

 

[DaftPunk]

Why would you buy the parts before finding out how to do the job and what parts you actually need?

 

[ban-all-sheds]

You might think it a combination of ignorance and a decision that ignorance should not be a reason not to just press on, but I couldn't possibly comment.

 

[pmxcrw]

Hi,

The cable was bought cut length, so is a sunk cost. Motivation was that I could at least get it strung through the joists, not knowing when the developer intends to reboard the ceilings. If it turns out to be a waste of money then so be it, can just be abandoned or pulled back through.

The switch I wanted to use provides independent dimming of all four channels, controlled through home automation software. I looked at the option of using two transformers in each location, but then I need two of these switches (since they operate on the 12V side) and they are much more expensive than the cable. One beefy transformer vs two smaller transformers also seemed more cost effective.

Providing similar home automation dimming control on the 240V side also seemed difficult, needing compatible drivers.

The cable thickness was then chosen because it's carrying 12V power, at about 1.92 amps, so the cable resistance becomes an issue. I used a few voltage drop calculators online which all agreed that the 4mm2 was necessary for the 14 meter run to the opposite side of the room.

I'm not so concerned about having "proper" light switches, since the main overhead lights obviously have switches at the room entrance.

I'm also trying to minimise the extent to which I have to touch the existing electrics since relationships with the developer are difficult and a lot of the cabling has been damaged during their strip out. I don't want there to be any ambiguity around them being responsible for sorting out this damage, or trying to claim future problems were due to my electrician interfering (we've had 18 months of pain to get them to take the property back and sort out the joist / floor problems).

Ideally I'd get an electrician in and do the job, but can't imagine anyone would want to touch the current electrics given the damage, nor do I think the developer would agree to access during the week.

But I'm open to other ideas - or just abandoning the job if it doesn't seem possible in light of these constraints.

Many thanks for the help.

 

[JohnW2]

The switch I wanted to use provides independent dimming of all four channels, controlled through home automation software. I looked at the option of using two transformers in each location, but then I need two of these switches (since they operate on the 12V side) and they are much more expensive than the cable. One beefy transformer vs two smaller transformers also seemed more cost effective.

Do I understand correctly that your intention is to have the 'transformers' permanently supplied with 230V, with all the switching/dimming done on the 12V output side of the transformers? If so, that seems pretty unusual (at least, in my experience!) - I'm not sure how well such 'transformers' fare (e.g. life-wise) when continuously powered, nor whether they consume appreciable 'standby' power when there is no load (which could have an impact on running costs and the planet!). You obviously would have to have some sort of switching on the 230V side, if not only to provide a means of making it safe to work on the 'transformers'.

Kind Regards, John

 

[ban-all-sheds]

Transformers should be fine.

Switch-mode power supplies, OTOH, might not be.

But surely there's a good body of knowledge within the home automation looni^H^H^H^H^H community on how to marry that stuff with LED drivers?

 

[JohnW2]

Transformers should be fine. ... Switch-mode power supplies, OTOH, might not be.

Indeed, but I suspect we may well be talking about the latter (quite possibly with DC output) for the LEDs. Also, true (wire-wound) transformers presumably would have a significant (even if not large) 'standby' current if continuously powered-up?

But surely there's a good body of knowledge within the home automation looni^H^H^H^H^H community on how to marry that stuff with LED drivers?

One would have thought so.

Kind Regards, John