source for 12vdc LED fixtures

[LutzTD]

I'm spitballing changing over my house to use 12vdc LED lights and put a cell or two on the roof and a couple batteries in the garage to run it all. The first I want to experiment with since its the easiest to access is the 2 fixtures in my attached garage. These are 2 tube t8 florescent fixtures. I would like to find qty4 t8 bulbs that are 12vdc. or if I can pull them apart and remove the power converter and add resistors as necessary to make them run on straight 12VDC. Anyone have a source or a how to for changing them to 12VDC?

 

[grantw]

check your local RV / boat supply.

Most fixtures in RVs are wide input 12V DC for just that purpose.

 

[LutzTD]

check your local RV / boat supply.

Most fixtures in RVs are wide input 12V DC for just that purpose.

yeah I looked at RV stuff and it all tends to be small and low power since they are lighting small spaces. the T8's they have are 18" long not 48"

 

[LutzTD]

I did find a 24VDC whoa expensive. I'm thinking the make my own option is looking better. Anyone modified one of the retrofit T8 to 12VDC?

http://www.led-cfl-lighthouse.com/product/T8-4ftLEDTubes24V-PW-18Watt

 

[kelving884]

I have. All 120vac LEDs have an interal power supply to change the 120vac to some DC voltage for the LEDs. Unfortunately it's not 12vdc. When you disassemble the LED package you will find the power supply. Some times it's labeled with its DC voltage & wattage, some times you have to measure and guess. Then buy a DC to DC converter that will change 12vdc to the voltage you need and can handle the wattage required.

Sent from my SM-P900 using Tapatalk

 

[PhysicsDude]

Cheapest solution is probably to just buy 12V LED strips and then wire them up yourself.

12V LED strips can be bought for ~$10 for 15 feet, and you can get them cheaper if you buy straight from China.

Something like this:

http://www.instructables.com/id/Fluorescent-to-LED-conversion-under-30/

I thought this lighting method was pretty clever too.

http://www.garagejournal.com/forum/showthread.php?t=318843&highlight=LED+joist

Just make sure to watch the amount of AMPs your lights will draw... the amerage adds up quick when you're using 12V.

 

[Northislander]

I have an off grid cabin with solar panels a 12 volt battery bank and 120 volt inverter
Trying to get around the standby losses on the inverter when i only want a couple lights on.
I wired a 10 gauge lighting circuit in each room for 12 volt lights the problem with the lights is finding decent looking dc rated switches at an affordable price.
I used the Leviton 56081-2w switches so they matched my 120 volt decora switches. But at $50.00 Canadian a switch i only ran two 12 volt lighting circuits.
I used 12volt cold cathode compact florescent bulbs originally but have been replacing with 12 volt LED's

 

[couch67]

http://www.garagejournal.com/forum/showthread.php?t=341085

LutzTD, Going with standard 12V LED light bulbs could be an option for you. I set this up a few months ago in my shed. 60w equivalent bulbs, they have been perfect. If you are looking to convert your house, these can be bought in bulk online.




couch

 

[justsam]

I have an off grid cabin with solar panels a 12 volt battery bank and 120 volt inverter
Trying to get around the standby losses on the inverter when i only want a couple lights on.
I wired a 10 gauge lighting circuit in each room for 12 volt lights the problem with the lights is finding decent looking dc rated switches at an affordable price.
I used the Leviton 56081-2w switches so they matched my 120 volt decora switches. But at $50.00 Canadian a switch i only ran two 12 volt lighting circuits.
I used 12volt cold cathode compact florescent bulbs originally but have been replacing with 12 volt LED's

Unless you need the momentary switch function as in your example, I would just use the standard Decora switches. Just do not exceed their typical 15 Amp rating.

 

[Northislander]

oops my model number for the decora switch was supposed to be 56021-2i its not momentary contact.
Unfortunately my cabin is off grid but still falls under an inspection area and the local electrical inspector won't allow a standard AC rated switch on a DC circuit and if anything went wrong i don't think my insurer would like it either

 

[justsam]

Even considering the contact wear from dc arcing on contact break, I would suspect if you kept the current low, and frequency of use low as would be expected in a cabin there would not be an issue.

If the AHJ says it is an issue, than clearly it becomes one. It could be done with relays but that just makes it more complex, and may as well just seek out dc rated switches.

 

[LutzTD]

Thanx for the comments so far. I did not think about the switch ratings for DC. I will also add that to the request here.

I like the 12v bulbs listed except I want to get away from edison sockets to avoid confusion on voltage. I would like to get whole fixtures or direct wire fixture so incorrect bulbs arent used with wrong voltage, like putting a $12 12vdc led bulb in a 120VAC fixture

 

[LutzTD]

I have. All 120vac LEDs have an interal power supply to change the 120vac to some DC voltage for the LEDs. Unfortunately it's not 12vdc. When you disassemble the LED package you will find the power supply. Some times it's labeled with its DC voltage & wattage, some times you have to measure and guess. Then buy a DC to DC converter that will change 12vdc to the voltage you need and can handle the wattage required.

Sent from my SM-P900 using Tapatalk

that's interesting. I'm not above using a couple batteries and going to 24, 26, or 48 to reduce wire sizes. I have seen some LED lighting that uses power over ethernet so they are using very small guage ethernet cable, how are they getting away with the smaller wire?

 

[Bert_]

that's interesting. I'm not above using a couple batteries and going to 24, 26, or 48 to reduce wire sizes. I have seen some LED lighting that uses power over ethernet so they are using very small guage ethernet cable, how are they getting away with the smaller wire?

Probably very low wattage, but thats just a guess.

Going with a higher voltage would definitely help with voltage drop and keep wire sizes to a minimum. Some of the led strips can be had in higher voltages or wire several in series to run on your desired voltage. Downside is that most other dc stuff gets expensive in higher voltages.

You could get full on ridiculous and go 120vdc, then most 120v ac stuff with a switch mode power supply (most LED's CFL's TV's computers,/ect), brush motor power tools, and resistive loads could run off it.

 

[mopar4wd]

Here are a few boat sources
https://www.alpenglowlights.com/
https://store.marinebeam.com/marine-led-fixtures/
http://www.imtra.com/
For switching IMTRA above sells European vimar stuff thats nice.
I would look at Carling Contura rockers they are common in the marine world but won't fit a standard box.

 

[PhysicsDude]

I have seen some LED lighting that uses power over ethernet so they are using very small guage ethernet cable, how are they getting away with the smaller wire?

The higher wattage PoE standards use high voltages to get the higher wattage.

The 60+ watt PoE devices use 70-90+ volts and put voltage on all 4 pairs (instead of just 2 pairs like typical PoE). Its also worth noting that there are no IEEE standards for more than 30 watt PoE yet, so far its all proprietary stuff.


I personally would stick to using a power inverter. I think the increased power loss from increased amperage of using 12V vs. 120V probably cancels out a lot of the gains you get from switching. I don't know exactly how many lights you want to install, but its unlikely you can get adequate lighting using the existing wires. And, as you and others have noted, it would be hard ($$$) to get everything up to code using DC. That's not something that I would really care about, but it may be important depending on your situation.

 

[LutzTD]

The higher wattage PoE standards use high voltages to get the higher wattage.

The 60+ watt PoE devices use 70-90+ volts and put voltage on all 4 pairs (instead of just 2 pairs like typical PoE). Its also worth noting that there are no IEEE standards for more than 30 watt PoE yet, so far its all proprietary stuff.


I personally would stick to using a power inverter. I think the increased power loss from increased amperage of using 12V vs. 120V probably cancels out a lot of the gains you get from switching. I don't know exactly how many lights you want to install, but its unlikely you can get adequate lighting using the existing wires. And, as you and others have noted, it would be hard ($$$) to get everything up to code using DC. That's not something that I would really care about, but it may be important depending on your situation.

The idea would be to convert the whole house eventually to a DC system running from batteries that have solar charging. Doing a count of lighting I have 14 ceiling fixtures with a total of 1420 watts (equivalent incandescent). I have florescent bulbs in all of these now so I'm using the equivalent incandescent number. Some of these are in ceiling fans, so I would have to figure a way to run the light with DC while the fan is still wired AC

 

[LutzTD]

so for the electrical guys out there, do you think in the end with the extra cost of switches that it would be better to convert the batteries up to 120VAC using an inverter then use standard 120VAC led fixtures? Seems like a lot of conversion loss but that's just going to mean a bigger solar cell right?