Can I cut Christmas lights?
18-AWG parallel wired Christmas cords can be cut to fit, while mini lights or LED string lights that use 2 or 3-wire 20-24 AWG wiring harnesses wired in series cannot be cut to fit the installation. Watch the video or read the transcript for more information.
I’ve assembled this mess of Christmas lights to answer a simple question, can Christmas lights be cut? Other forms of the question are, can glass mini lights be cut, and can LED light strings be cut? These are the types of strings that are really in question.
You can see that this is a traditional glass mini light string with a wiring harness where the wires come out of the base of the bulb, and this is an LED set where the wires also come out of the base of the bulb. This means that these strings are wired serially. So, the short answer is no. Serially wired Christmas tree lights cannot and should not be cut and reassembled to change the number of bulbs, the order of the colors, or modified in this way at all. The results, if you do take out some of the bulbs, or reorder them, or solder them, that’s going to change their electrical characteristics. It’s going to change the amount of current running through the lights. Cutting the lights will void the warranty no matter who you buy them from and can possibly create an electrical hazard.
Now, for those of you, and you know who you are, who are arguing in your head with me right now. You can cut these lights, strip the wires, and solder them back together. You might be able to get away with that on the glass bulbs, but these are ultra-low current LED light strings and will damage the lights where they might not even come on again, or their lifespan will be significantly reduced. Because we know from basic electricity 101, from Ohms law, that if you adjust the resistance of any string of lights, it will change the current running through them, and that’s the issue.
So, if you need to cut a light string to fit a project, the only type of light string that can be cut to fit is a parallel commercial traditional C7 or C9 18 gauge Christmas light cord. You see, it’s the kind where you could install your own bulbs, and you know that when they’re plugged in if you pull one bulb out, the rest will stay lit.
So, thank you for all your questions, and please keep them coming. I’m Shellie, at Christmas Light Source.