Retrofitting a CFL Light Fixture to LED





Introduction: Retrofitting a CFL Light Fixture to LED

Well, here goes - this is my first Instructable.

When we bought our house several years ago and updated all the light fixtures from old style to a look more consistent with our taste, two fixtures we selected used the compact fluorescent tubes as shown. Unfortunately, these tubes contain Mercury, are expensive ($7 each at the orange big box store), and have not lasted as long as their advertised expectancy. When yet another set of bulbs died after only a couple of years, I said, "That's it!" and looked for an alternative. Replacing the fixture is an option, but picking a style between two people proves to be very difficult. So, being an Electrical Engineer looking for projects, I came up with this retrofit. As usual, the standard disclaimers apply. Obviously, the fixture warranty is void. Use common sense when working with electricity (TURN IT OFF), I am not responsible for anything that happens if you choose to try this, and practice proper precautions when working with tools and wiring.

Also, please consult your local wiring codes and laws. Some countries may prohibit this type of modification as it would violate regulatory requirements.

Now that the formalities are out of the way, here goes.

Step 1: Gather Your Supplies

Prior to starting the project, I needed to figure out how I would do the retrofit. I had thought about buying a standard brass colored table lamp socket and fashioning a bent metal bracket to secure it. But, during a visit to the orange box box store to purchase the LED light bulb, I found these parts which are meant for building and/or repairing lamps. And....the light bulb (in my head) turned on. The lamp socket pictured here would be perfect, with one minor modification!

Step 2: Disassemble Fixture

First, turn off power, remove the fixture from the ceiling, and disassemble it by unscrewing the ballast and lamp sockets. Be sure to use caution when removing wire nuts, use eye protection in case debris falls from ceiling and/or junction box, and make sure power is TRULY off. I have had some occasions where two circuits reside in a given box. One never knows how a previous owner or house builder wired the place!

Step 3: Prepare Lamp Socket

As shown in the photo, I had to make a minor modification to the lamp socket. The threaded bracket is meant to hold the socket above the wired base of a lamp. I removed the screw, used two pairs of pliers to bend the bracket, and then reinstalled it. You need to achieve an angle of "the light bulb fits within the base and cover of the fixture". In this case, I used my Italian cooking method of "yeah, that's about right" to set the angle of the bend.

Once reassembled, add the smallest threaded nipple rod from the package and one retaining nut to the socket assembly as shown. Of course, depending on your fixture, you may need to use a different length nipple.

Step 4: Mounting and Wiring

Harvest the black and white wires from the ballast. Take note of their condition. If they are frayed or look damaged in any way, take the safe route and purchase some new wire. 16AWG or 18AWG stranded will be sufficient as the power consumption is minimal.

Strip back the insulation and secure the wires to the socket. The BLACK wire MUST fasten to the terminal for the inner tab of the socket and the WHITE wire to the threaded outer shell. This way, you will have less of a chance of shocking yourself should you accidentally touch the threaded base of the bulb while installing it into a live fixture. However, see my earlier disclaimer of making sure the power is OFF to the fixture first!

Secure the socket assembly to the fixture by selecting a hole which will centrally locate the bulb within the fixture. On my fixture, I located the bulb slightly off center within the fixture to avoid an interference with the thumbscrew that secures the fixture to the ceiling. Feed the nipple through one of the available holes in the fixture and secure with another nut. If no holes are conveniently located, drill a new one.

Feed the wires through the nipple. Use caution not to chafe the insulation or pull too tight as to put strain on the terminals. Leave a small service loop in the wires near the socket. One step I forgot was to add an Underwriter's Knot in the wires per the attached photo. However, I think in this case the fixture should be okay because unlike a table lamp, this fixture will be affixed to the ceiling and not subject to having its power cord pulled or moved once installed.

Be sure to secure the ground wire if it came off during the initial disassembly. I reused a ballast mounting screw and lock nut to secure the ground wire.

Step 5: Reinstall Fixture

Reconnect fixture using wire nuts. Take your time and use care to make sure wires are safely tucked into ceiling box or within mounting provisions of the fixture so they will not get pinched or damaged when the fixture is secured to the ceiling. Secure fixture in the reverse order you removed it from the ceiling. In my case, a threaded nipple extends from the fixture mounting plate previously mounted to the ceiling box which accepts a thumb screw. You can see this thumb screw under the light bulb.

Once everything is tidied up and secure, turn on the power and test your newly retrofitted LED powered light.

My fixture now produces a similar number of lumens using less wattage, and it will hopefully not need a replacement bulb for several years.

I hope you enjoyed my first Instructable.



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    15 Discussions

    So, you're an electrical engineer, you write a thorough, clear instructable in cohesive, articulate sentences......and you're drop-dead handsome.

    Not jealous....nope.....not envious at all....


    1 reply

    LOL! Thanks for the compliments! I am hoping to develop additional instructables in the near future as I attempt to free up some non-work time.

    This is a really cool idea that I would like to implement in my own house, but I'm nervous about doing anything with the electrical systems. My husband likes to think of himself as a repairman, and does most of the around the house work himself, but electrical work is too dangerous for him to try. I would much rather leave it up to the professionals who know how all this stuff works, and will stay safe.

    I feel I should warn people that in some countries the conversion shown here would be illegal. In Australia and NZ the terminal screws are not permitted to be able to be contacted by anyone changing a lamp if full mains voltage is connected to the terminals, even through a choke etc. I would suggest therefore that you ensure that the lamp-holders are of a type that has all electrical connections shielded suitably from contact. Of course the Active conductors in Edison Screw sockets must be the centre connection. One other small problem is that all work which would be connected to mains voltage must in Australia and NZ, be carried out by a licenced electrician

    1 reply

    They must have one hell of a union. As owner of MY house I am allowed to fry my self if I so desire. [ me..I usually end up on the floor with thoughts of "remember that one; don't do that again"



    Great Instructable, I'll use this to adapt the light over the garage door the next time the bulb needs replacing. Just one question, why didn't you replace both sockets? Will the 60w bulb be enough light to replace the two CFLs?

    3 replies

    Those CFLs are normally around 15 watts so 2 of them making 30 watts (on paper). That single 60 watt is already double that. I understand the more is better mentality but being an electrician rarely does one need 120 watts of light in a space these types of fixtures are mounted. I'll leave the heat sinking and other issues to the electrical engineer.

    No - you missed the point - it is not a 60W bulb it is a 60W equivalent LED bulb (typically ~9 or 10W) so even if he had used two of them you would be below the energy consumption of the CFL (based on your numbers).

    This particular fixture is mounted in a Hallway. I determined that even with one of the 13W CFL's having failed, there was just about enough light produced by the fixture, so replacing both tubes with one LED bulb would be fine. This may not be the case for all fixtures. I plan to do this retrofit in my master bedroom which has a similar two-tube fixture. In that case, I may opt to either use a single 100W equivalent LED or two 40W equivalents. I used two 40's in the kids' rooms, and they are well lit. It comes down to the number of lumens rather than the Watts. New lighting technology is becoming more efficient (i.e. more lumens produced per Watt consumed). Compare the lumens produced by your existing fixture to the number produced by the LED bulbs to help you decide on one or two LEDs. Personally, I like the LED's because they consume so much less power and run cooler (no more need to worry about high temperature rated wiring). I hope this answers your question.

    Excellent point, Billypil. As part of the disclaimers, I will try to add a comment to make sure to check with local codes and laws to ensure compliance. I recall when shopping, I did come across a weatherproof socket with the terminals covered. However, this would would have required fabrication of a mounting bracket. One option to protect the end user from exposed terminals could be through the use of heat shrinkable tubing and electrical tape. Apply tape over the screw terminals after securing the wires. Then slide a small length of wide heat shrink over the socket and shrink it to form a shroud over the rear, thus trapping the tape in place and making it as difficult to touch the rear terminals as it would be to touch the socket tab.

    I haven't tried it yet but it sounds very doable. Great idea. I'm looking forward to changing out some fixtures. Thanks.

    Thanks, this is just what I wanted to do.