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I want to light a dining area that is ~12'x 18', with exposed wood ceiling, supported by beams that were created with two 2"x 10" framing lumber, with a 1"x 4" bottom cap. Wiring for the current lighting (track lights) runs in the space between the 2"x 10" members in two "beams". The beams are spaced ~26" apart.

A friend gave me four flat metal LED panels that were removed from display ceiling lights, along with two drivers. The LED panels are 7"x 15", with 112 LEDs on each. I contacted Cooper Lighting, for specs, and their reply:

PEL2000835 = LED Panel, 7"x15", 2000 Lumen, 80CRI, 3500k. PLE2000835 is a discontinued product that was made for us by a third party.

The drivers are Phillips Advance XITANIUM 48W 2.0A, 0-10V Dimming.

Questions:

  • Are the drivers usable for more than one of the panels?

  • Should they be mounted off of the wood, suspended to allow air circulation, or would they be OK enclosed between the 2"x10"s? I've had one of the panels on for two hours, and the driver is warm to the touch, resting on the floor, but not "hot".

  • Would two of these, spaced 5' apart, be sufficient to illuminate the area, or should I go with four panels, with dimmers?

Thanks for any help.

  • Is there a current or power spec on the panels themselves? – Chris M. May 11 '17 at 14:29
  • At 2000 lumens I would expect the lamps only draw ~18w so 1 driver should power both with room to spare, 3500k is a bit lower on the spectrum than I use it may not appear as bright as higher values. I would hook them up and space them out to get an idea but I have 4 ea 4' leds covering ~ 20' , each is 3000 lumens and this is quite bright only a total of 4' may be a bit dark between and at the ends but this all depends on how the panel was designed the beam angle may be different or a diffuser that direct the light differently than tubes – Ed Beal Oct 17 '18 at 23:38
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For more info I pulled up the spec on XITANIUM Drivers and I'll go ahead and take a shot at answering your questions but reusing equipment is tricky.

In answer to your first question. If you gave Cooper the same information you gave us the driver is probably for one strip. We don't know because I don't have the power rating for each strip and I'm not sure you will find it on the strip and, even though we know the number of LED's per strip, LED's come in different sizes.

Second question: The specifications show a heat generation for those divers to be 90 degrees C or lower which is Less than 200 degrees F. So they won't burn wood. A rule of thumb is that if the drivers have mountings on them. They should be ok for surface mounting, but it would be a better installation if you pulled it off the surface for heat dissipation. The biggest problem I see is how are you going to protect the conductors and the connections you're going to make since you can't splice in free air.

Third question: Unfortunately I don't know of any illumination requirement for a residential kitchen. It could be anywhere from 20 footcandles up. The code only requires a certain amount of watts per square foot for calculation only. So your best bet would be run all four with dimmers.

If you could temporarily connect at least one up as a goby and have the right kind of meters. All of us might get enough information to answer some of these questions with more detail.

  • I'm not sure what you mean by "you can't splice in free air". Do you mean that code requires splices to be protected by a box? The connections I plan to make would be "protected" by location between the ceiling & a tempered glass panel (8" vertical air space), set on wood strips screwed along the bottom edges of the beams. The glass will be frosted, except for areas where colored glass pieces will be attached to the upper surface of the larger glass panel (26"x 48"), so there would be no visual availability of the panels/drivers/exposed wiring, and no chance of accidental physical contact. – glassblastertoo May 12 '17 at 14:43
  • In looking closer at the panel, I found a tiny box with the following notation: PCB INFO, 610023, 94V-0, 12 14. The twelve and fourteen are printed one space apart, and the lines creating the numbers are segmented. I have no idea as to what they might mean. – glassblastertoo May 12 '17 at 15:19
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To give you a rough idea, a new 4' fluorescent tube puts out in the ballpark of 3,000 lumens, which decreases with age, and a substantial amount is lost in the fixture. LEDs are directional. So each panel will deliver roughly the amount of light of a one-tube fluorescent fixture with a fresh bulb. The light will be fairly concentrated under the LED fixture. The total light from the four panels is in the ballpark of what you need for a room that size for good illumination, and it sounds like they are dimmable from there.

In a dining room, you typically want most of the light over the table. The amount of spread will depend on how high the ceiling is. Figure out the best location by looking at the spread pattern in a dark room. You can shine them at a wall from the same distance as the ceiling is from table height.

You will probably get the best result if you overlap the illumination so that the weaker edges add to a brightness more comparable to the center of the light from each fixture rather than acting like four spotlights over different areas of the room. Depending on the shape of your table, you might get the best illumination pattern arranging the fixtures in a square array, a diamond array, or a linear sequence.

Depending on the amount of spread, you may have to compromise (the ceiling may not be high enough to achieve a lot of light spread). You might improve the spread by putting the fixtures behind diffusers. You can assess the effect with the wall test.

LEDs put out the least heat vs. light of the common home lighting sources. Even incandescent fixtures can be mounted against the ceiling, so there isn't a safety issue mounting LED panels against the ceiling. However, heat can shorten the LED life, so it wouldn't hurt to leave a small air gap for circulation.

Look at mounting the panels at a slight angle from the ceiling. This can accomplish several things. It may give you more control in positioning and aiming the light. Light from the angled fixture will fall on a larger area, spreading the light more. And the angle will create an air flow above the fixture to provide some natural cooling (air will flow toward the higher end). If the panels are in a square or diamond pattern with the center of the pattern lower (so the panels are aimed out), it may naturally circulate the room air like a ceiling fan at a low setting, rotating in the direction of blowing the room air upwards.

  • I powered a panel, and placed it on the floor, shining upward. It appears that four of the panels will supply more than enough light to illuminate the dining area, but some light will be interrupted by the panels being 6"-8" above the lower edge of the beams, casting a 'shadow'. I hadn't thought to angle the panels, which should help if I place them close to one side of the space, angled down toward the table center. The frosted glass below should help. Is there some kind of meter I could use to tell if the drivers will work for more than one LED panel? What would happen with an overload? – glassblastertoo May 12 '17 at 15:10
  • If the beams are an obstruction, you could lower the panels a few inches. Lumens/watt varies for LED lighting. Check the panel or specs for their power requirements. The household LED range looks like the neighborhood of 40-100 lumens/watt, which would suggest that a 2000 lumen panel would require roughly 20 to 50 watts. The drivers are 48 watts input, but the maximum output is only 20 watts. This suggests that they are rated to drive one panel. If you try to pull more power, it is likely to just burn it out. – fixer1234 May 12 '17 at 18:46
  • My installation has been running now for over a year, with no problems. One driver runs two of the LED panels, and I have a dimmer attached to each pair of panels. The light from the four panels is more than adequate, and for most use the dimmers are set at about 50%. At full power, the room is brighter than necessary. The panels are angled downward about 20* from vertical, and there is no obvious shadowing in the room, though the directional nature of the LEDs creates a 6" shadow on the ends of the 4' long frosted glass panels. We're pleased with the effect. – glassblastertoo Oct 19 '18 at 12:52
  • @glassblastertoo, thanks for closing the loop. Great to hear that this worked out for you. – fixer1234 Oct 19 '18 at 20:19

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