On Sunday, 17 December 2017 22:38:05 UTC, Phil Addison wrote:
My old fluorescent under-kitchen-cabinet tubes are failing at an ever faster rate, so I'm
thinking of replacing with LEDs, particularly flexible LED tapes.

A few things I'm not sure about...

The light output is quoted in lumens per metre, but how many do I need?

How long is a piece of string. What do your current lights put out, estimate from there.


I've seen outputs
from 290 to 780 lm/m for 12V systems and up to 1200 lm/m for 24V. The tapes will be 45cm
above a dark textured work surface. I suppose you can put 2 tapes side-by-side for a
higher output.

of course

The kitchen layout is U-shaped with the sink in front of a window with cabinet runs either
side. At each side of the sink the runs are finished off with a little angled/corner shelf
unit at right angles to the main run. I'd like to run the last bit of tape around this
corner if possible. Is it possible to twist it through 45 degrees or will a I have to cut
it and use a wired connector?

if out of sight you can twist it on the corner. If visible that wouldn't look good.

Can I just stick the bare tape to the underside of the cabinets

yes. If out of sight you could cover it over with velcroed clear plastic bottle strips to keep them clean.


or does it need to be
mounted into a holder such as RS Stock No. 797-2432, a horrendously expensive product!

there's never any reason to buy anything from RS.

Then there's colour temperature. My fluorescents are 2700K but a lot of the white LEDs
seem to be 3000+. I don't suppose that's a big deal in this application.

3000K is not as yellowy tinged as 2700K. I'd avoid higher CCTs unless you know you want them.


What about drivers. I assume I'll just need a couple of basic 12V drivers, one each side
of the sink - though the hob interrupts the run on the right, so I'll either have to route
some cable round that of use a 3rd driver for the last cabinet which will only has a 55cm
LED run. I have easy access to the 240VAC that's feeding the 6 existing tubes. Something
like a couple of RS number 773-6949 drivers giving 1 amp each?

12v 1A is 12watts.

Any advice much appreciated, and any recommended suppliers/brands.

Phil

I'd give them at least one dimmed setting. For relaxed use it looks better and extends LED life hugely. A series cap on the mains feed can do that, as long as the PSUs don't misbehave.


NT