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Hello and thanks for your help.

I will be as precise as I can

I have 112 feet of 8 foot flouersent bulbs (14 8 ft units) The current configurations are so that the fixtures are run in a series of 110v 3 wire with every other fixture on the same circuit. I am leaving the fixtures and disconnecting the ballast. I am running strip LED lighting over the existing fixtures.

I will be replacing four bulbs with two stips of 5 meter led strips. The strips are rated per 5 meters at 12v 5a per run.

My question is: 1- do I have one massive transformer at the end of each unit and run individual wires from the transformer to the end of the light strip?

2- where the end of 4 light stips come together do I put in a 12v 20 amp power supply and run off of the 120 lines already there.

3- trying to achieve the most consistent lighting, do I chain the lights together and then run one common back to the supply.

4- I am up to suggestions as it can get very expensive as I have 4 sets of 112 feet to run and power supplies can get very expensive placing one at every junction.

FYI The 110 currntly running is 12ga stranded wire and I can use that if needed.

Thanks in advance as I have no clue about 12 volt stuff.

Rich

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  • Frankly your better off getting some of the commercial led replacement tubes. They are meant to replace the florescent bulbs and run off 120V naturally so you can just remove the ballast. – cde Nov 28 '15 at 4:26
  • What part of the world do you live? – Kris Nov 28 '15 at 19:50
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While @cde 's comment is noteworthy, I try to answer your question as good as possible. One note: the right word for the things providing power to LED-lighting systems is "LED driver" in the US and "electronic control gear" (ECG) in the rest of the world. Naming it transformer leads to confusion. I'll use "transformer" here, for consistency, though.

Option 3 will yield the probably worst result. 112 ft will pile up astonishing 35 A current on your wires. While gauge 12 is sufficient to bear that load without causing fires, it will suffer a significant voltage drop of up to 1V at the end of all striplines. This means you may encounter dimmed or even no light output from the most remote LED striplines.

Option 1 suffers the same drawback but not to this extent.

Option 2 is probably the best option for minimized power loss and homogeneus light output.

You do not write if all your 8ft tubes are adjacient, so there may be significant cable length to add for the calculation of a voltage drop.

I'll try to summarize some general advice for your situation.

  1. If you can, mount the transformers as close as possible to the LED strips in a 12V system.

  2. Compare prices. Single huge transformers do not necessary save much money compared to smaller ones. Smaller transformers can be placed closer to the LED and in confined spaces.

  3. If you have to run long lines with high light output, switch to 24V-Systems. Transformers are smaller, you can chain more LED-strips together and you can use longer and thinner cables to connect your LED-strips.

  4. Pay close attention to the specifications of LED-strips and transformers. In most cases a 12V transformer for halogen lights is incompatible with LED-strips. You need a LED driver or ECG (electronic control gear) specifically designed for LED lighting.

  5. consider using retrofits, as cde suggested. But you have to pay close attention if they meet all regulatory laws in your country. There are plenty retrofits on the market which pose a fire hazard or hazard of electric shock to their users.

  • Good answer... just to add, if you go with option 2, you can help with voltage drop (which causes variable brightness across the strip) by running the (-) side of the transformer to the far end of the strip. See budgetlightforum.com/node/9394 – Aloysius Defenestrate Nov 28 '15 at 15:56
  • The OP didn't state where they were from, but given they mentioned 110V Volts it's safe to assume USA or similar. In the USA, the correct term is not electronic control gear but LED driver. – Kris Nov 28 '15 at 17:43
  • Googling 'led driver' is likely to create more confusion, as that refers to something entirely different in the flashlight world. – Aloysius Defenestrate Nov 28 '15 at 18:33
  • I googled it and nothing about flashlights showed up. The point is if the OP were to go asking around for a electronic control gear in the USA they'd probably get a lot of confused looks. – Kris Nov 28 '15 at 19:48

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