In my Texas, one story frame house, the ceilings have been insulated with loose fiberglass insulation. The kitchen lighting has been replaced with LED inset flood-type lights. The ones that were chosen are powered by individual 120v AC to 126v DC converters. These converters are small 3 3/8" by 3 1/4" by 1 1/4" steel box (no vent holes). These have a habit of quitting. The power supplies are not sold as a unit, but must be purchased with a new light. Lasting time in the Texas summer is in the range of 2 months.
I would like to find a single power supply that would power 8 lights, and be located in the air conditioned portion of the house instead of the hot attic. Any ideas? I have not found a power supply (on Amazon type locations) that looks like a good match. Any answers? Bob

 

Can you supply links to any of these devices? Never heard of such a thing.

 

Maybe it’s a typo but I’m concerned by the idea of domestic power supplies which have a 126V DC output. Any DC voltage above 50V is dangerous.

How about replacing the lights with 12V LED down lights. There are lots of power supplies available for these which can happily sit above the ceiling, they are very efficient and typically don’t run hot. You may need more than one depending on the rated power and the power of the lights but more than one light can usually be connected in parallel to one supply

 

I would replace lights with ones that run directly from AC line voltage. These are very common, more so than DC powered ones.

 

I also am guessing that the voltage to the lights is 12.6 volts. That can be easily verified by removing on of the lights with the failed supply and powering it with a 12 volt DC source. Polarity matters a lot, so hopefully there is some indication of polarity for the connection to the failed power supply.
For the substitute supply, there are many producers of good quality power supplies, not listed on ebay or other mass distributor sites.
But before going any farther with advice please verify that they work on 12.6 volts and not 126 volts, which I believe is not correct.

 

AC to DC converters are generally less efficient than DC to DC converters, so a mains-powered light is likely to generate more heat loss from its power supply than a DC one.
The best way would be to use LEDs with no power supply and run them from a remote constant current driver.
Good LEDs are close to 50% efficient, so only half the rated power has to be dissipated into the ceiling void

 

In most houses here in the USA, the electrical distribution is AC, usually about 120 volts. So a transformer will be the better choice, add a rectifier and it is still quite efficient. AND no problem with it generating electrical noise, unlike the cheap power converters used with many of those lights.
And "good luck" finding decent looking light fixtures with LEDs that do not come with a power supply of some sort. In addition, 12 volt LED lights have something inside already.

 

I would replace lights with ones that run directly from AC line voltage. These are very common, more so than DC powered ones.

This is what I did recently. We tore out a kitchen and bath ceiling and I went with all new LED ceiling lighting. They are all 120 VAC 60 Hz lights. No cans and simple J Box mounting. Want to say I paid about $20 each from lows and bought a few spares just in case.

Ron

 

Those LED lights that run "Directly from 120 volts AC all have internal power conversion circuitry, because LEDs do not run on 120 volt AC. And in the failed ones that I have investigated, in every case, it was that conversion module that failed. So you are trading an external device failure for an internal device failure. That does not seem like a great benefit as I see it.

 

The benefit is the variety, ubiquity, and low price of 120V AC LED bulbs. And of course the ability to use standard - often pre-existing - wiring and fixtures.
The TS is in a pickle precisely because he has non-standard equipment, which we still know nothing about.

 

Those LED lights that run "Directly from 120 volts AC all have internal power conversion circuitry, because LEDs do not run on 120 volt AC. And in the failed ones that I have investigated, in every case, it was that conversion module that failed. So you are trading an external device failure for an internal device failure. That does not seem like a great benefit as I see it.

Well yeah. The ones I installed ran 24/7 for about 6 months until I installed some under the cabinets lighting. I have yet after a year have one fail and if they do I have replacements. If a $20 unit fails I just trash it (remove and replace) which takes about 10 min using a 6' ladder and screwdriver. I am not about to bother doing an autopsy.

Ron

 

I did not say that they will fail in a short time. BUT when eventually they do fail the matching replacement may no longer be available, nor will any replacement be as cheap. Prices around here are rising constantly. Inflation is at least part of that cause.

 

Maybe things are different inthe USA but 12V LED drivers like https://uk.rs-online.com/web/p/led-drivers/1766718 are very commonly used in the UK for multiple LED down lighting. This is an especially high powered high quality one - much less expensive ones are available with lower power.

I'm not much in favour of looping mains cable around in the loft - a real fire hazard. But you probably don't have squirrels getting into the loft space?

 

I would like to find a single power supply that would power 8 lights

I don’t think anyone has mentioned this: These drivers might be constant current drivers. If they are, they cannot be replaced by a single supply. Also, your 126VDC is highly unlikely.

Can you post a picture of any writing on the supply?

 

12V wiring is no more safe than 230V when it come to fire hazard, probably more dangerous as the currents involved are larger, and the ratio of the prospective fault current to the operating current is lower, and therefore more difficult to ensure an over current device triggers.
Low voltage wiring driven by a current limiter is a different matter - a lot more difficult to start a fire with 350mA, but not impossible.

 

None of us has suggested using other than good wiring practice and adequately sized conductors. And any decent power supply would have over-current protection.
And as for constant current supplies, when a light fixture specifies a voltage, usually 12 or 24 volts, the current control is within the device, not an external regulator. If the intended current is listed first, at that point a current regulation system would be required.

 

None of us has suggested using other than good wiring practice and adequately sized conductors. And any decent power supply would have over-current protection.
And as for constant current supplies, when a light fixture specifies a voltage, usually 12 or 24 volts, the current control is within the device, not an external regulator. If the intended current is listed first, at that point a current regulation system would be required.

Many professional luminaires are designed for constant current drive, commonly 350mA or 700mA.

 

Many professional luminaires are designed for constant current drive, commonly 350mA or 700mA.

Every one of those "professional luminaires" is labeled with the specified current, so it will be very simple to avoid them.

 

In my Texas, one story frame house, the ceilings have been insulated with loose fiberglass insulation. The kitchen lighting has been replaced with LED inset flood-type lights. The ones that were chosen are powered by individual 120v AC to 126v DC converters.

While the thread starter has yet to return I am venturing a guess the 126 VDC is maybe 12.6 VDC. Regardless I still suggest just buying LED lighting designed for 120 VAC and be done with it. No sense on beating this to death any further unless the thread starter returns.

Ron

 

"R" is correct, except that I do like lower voltage lighting. An upcoming project for one client will be to split the power modules from some LED fixtures and install the lights over artworks hung about six feet up on walls. Installing an electrical box that high up would leave a serious scar when the room decorations change in a few years. So instead, the power supply portion will be in a standard deep electrical box at the level of outlets in the room, very unobtrusive. And number 20 wire will run down inside the wall to the supply in the steel box below, where the 120 volt feed will continue down into the basement area, all the 120 volt wiring will be per the applicable electrical codes, The DC wiring will pass through a 1/4 inch drilled hole and then down to the box below. easily removed when the room decorations change. And an outlet below will not be out of place, That is where low voltage separated installations work well.