LED wafer lites for cathedral ceiling

['Pants]

Getting my rebuilt LR cathedral ceiling wired for new LED wafer lites has taken FAR longer in the planning than I expect it will in the execution. Ceiling has no cavity - it's solidly filled with iso-board insulation (like SIPs, say) so I've been debating all kinds of issues like potential for heat buildup, code-requirement for protection of wiring to LED devices, and low-voltage options. I do expect to carve out small pockets for each head to snap in, but not any bigger than necessary for that. Heads generally say something about being engineered to sink enough of the heat they will generate, so I think they'll do okay with their normal face-side exposure.

If I went with 120V-supplied LED wafers (which consist of a thin LED head paired with a driver intended to be tucked up into an open plenum ceiling at each head's location) I'd be worried about heat buildup, particularly because there would be zero ventilation for the drivers in my case. I also kinda hate routing #14 (encased in...armalite? what's required within the ceiling, after I carve channels into the foam, anyway?) because it's rated for ~15A, while my entire grid of LEDs would draw less than 4A.

That started me thinking about low-voltage (12VDC) options, but all I've found being sold are probably too low of a lumen output (3W LEDs = ~ 25W incandescent or about 250 lumens) intended for RVs and other mobile applications...and I'd still have to deal with power-supply and dimming concerns.

Getting back to the 120V driver/LED combinations, for a while I chased after the idea of customizing these setups, maybe centralize the whole batch of drivers by extending the provided short jumpers between drivers and LED heads. I then realized it would be better still to use just one large driver - if I could find one compatible - for the whole dozen or so heads I'd want to install. But I'm hearing there's way more to customizing drivers to work along those lines than I'd likely be able to or have time to deal with (knowing the LED head's requirements, whether constant-current or fixed voltage, the potential for unanticipated problems from running the heads as a big parallel network of the LED heads...etc).

It's hard for me to believe I'm the first guy to wander into this. It makes little sense to me to be using massive wire (even #14 is "massive" in comparison with LED power requirements) nor 120V power - from a minimum 15A circuit - to get this done, and that'd be the case even if I had ample plenums to tuck the drivers into: running the LEDs from these components is like drinking from a firehose. Am I right in thinking that the NEC hasn't/can't keep up with such developments?

Let me know if you've got a better way than any of the above options...maybe a source for 12V off-grid housing lighting that isn't as dim as the stuff I keep finding online?

Dave

 

[WorthFlorida]

It really comes down to the manufactures installation requirements. It should list spacing needed around the fixture. Low voltage wiring has very little or no restrictions in a residential setting. The one problem with low voltage wiring could be the voltage drop with long runs but then where do you install the drivers?

The specs on Lithonia brand is direct contact with insulation is allowed. They offer up to 20’ low voltage extension cables. This makes it possible to install the drivers at another location, perhaps a better choice in your application. For your application go with color of 2800-3500k. 4oook and higher, thought the specs claim a higher lumen output, the color will look like fluorescent lighting and hard on the eyes.

If you have a wide open cathedral ceiling, installing fake beams to hide the wires could be an option.

https://lithonia.acuitybrands.com/search#q=led ultra-thin wafer&t=ablAll&sort=relevancy

https://img.acuitybrands.com/public-assets/catalog/579430/wf6.pdf?sv=2017-04-17&sr=b&sig=+murxhvbtQPDYzrwOsUR1sDj0Afgm2zHLWDbIfFr2EA=&st=2019-09-15T11:21:56Z&se=2019-09-15T11:26:56Z&sp=r&rsct=application/pdf&rscd=attachment;+filename="wf6.pdf"&abl_version=09/04/2019+17:18:55&DOC_Type=SPEC_SHEET

 

[Sponsor]

 

['Pants]

Some sellers like these guys sell and describe this type of head/driver combo being routinely installed in thin-ceiling applications, with extensions of up to 50' to get to a centralized location for drivers...but I don't see much detail on using their larger drivers that apparently will consolidate. Gonna have to call 'em on Monday. They're definitely not selling at low-level prices, though - much more.

It's really confusing to me because of the randomness, lack of specs, some have voltage-ranges that approach 50V - it's not just 12V or 24V.

I also ran across that same gimbaled wafer unit you linked. They're probably about what I need for my 17-degree sloped ceiling - but all the old questions about wiring to them remain. I've no idea what their basic voltage-range is, and it seems like it's a lot more involved than just that, anyway.

I want to preserve the unbroken plane of the ceilings as is, so whatever wiring I run will have to be installed in channels in the iso-foam.

 

[Jadnashua]

FOr a low-voltage option, a couple of companies may speaker wire that is made from wide-flat strips encased in a thin plastic. You could probably cover that with drywall mud and make them disappear. That's what they are designed for when used as speaker wires, anyways. Don't know if it would work for you, but could be an option. https://www.amazon.com/Ghost-Adhesi...=2025&creative=165953&creativeASIN=B079MMFVFJ

 

['Pants]

Yes, I'm going that general direction. AliExpress has some (but not many) vendors selling 12V/24V RGB types, together with whiz-bang controllers and consolidated transformers, just as I started out looking for. And the heads are fed with five-conductor ribbons (maybe 20-ga?) that are not too expensive, and now I'm thinking I can stuff those sideways into the tight gaps between my iso-board insulation and rafters. The trick will be to leave the ends fish-able somehow, after my ceiling (OSB, not gyp) is in place and I've been able to core out holes for the heads in the right places - plus carve out whatever small pocket is required for the head itself. Anyway, I sure don't want to core into my ribbon...

In all my research on this, finding the variety that's out there tends to make me progressively more selective. With my sloped ceilings, where before I wasn't too concerned with not having my light-cones from these fixtures shining at 90 degrees to the floor, now that I've seen some wafer heads with gimbal/eyeball adjustment for this purpose, my demands are honed even sharper. Trick is to actually pull the trigger!

 

[WorthFlorida]

If you want mood light, RGB are good but not good for white. The cable is four conductor, not five and usually at 22 gauge and flat ribbon, not round. At a white setting the lumen output is less than all white LEDs.

A problem with Alibaba stuff is it’s usually one of a kind. In the future should a wafer led go out, and they do go bad, you’ll not find a replacement. Drivers have become standard for RGB and many have remotes.

It’s your ship to do what you want. Lol