View Full Version : cutting light strings

12-05-2009, 10:21 PM
i would like to know if it is possible to cut led light strings. Not to cut them in the middle but mabey only 10 lights off. After cutting them I would like to add them to another string that is just a little to short; like 3 bulbs.


12-06-2009, 01:54 AM
Cutting LED strings requires re-wiring and re-calculating resistor values...

It's a lot of work but possibly do-able

12-06-2009, 09:47 AM
The only easy LED cut is with 50 and perhaps larger strings.

If you look at 50ct, you will see it's really two 25's that are spliced together in the middle. In the middle you will find the only section that has two wires in it. You can cut it there and do nothing else to the string if you want.

However, as noted before, moving just a few bulbs is next to impossible. It will require you to see what resistors are already in the string and redoing them with a new value.

11-21-2013, 08:26 PM
Hello All,

I know this is an older thread, but I am new to the whole light string cutting thing. I have a situation in which I want to make a 6 channel snowflake in which each element is a channel. The snowflakes I would fall into the size of about 30" to 42" wide. The light strings I have are 50ct and I think this is too many for a single element. However, I was reading here and in other places that most 50ct light sets and above are wired in series/parallel and that each series section can take the normal 120 volts. If I could cut these sets down to 25ct that would be a much nicer number to work with in terms of wiring up each snowflake element.

I am looking at the new LED strings I bought from Walmart and it seems like that these lights just MIGHT have two 25ct sections. I will describe the set to the best of my ability. Upon removing the string from the box, it twist-tied together in two sections...conveniently it appears that each tied off point is a section. Looking carefully at each light socket, I noticed that each end socket and the middle socket have three wires coming out of them. In addition, on each end of the lamp there is what appears to be a capped off light socket. I am assuming these are the diodes used to run the set.

Now would I be correct in assuming that I have to make my cut right after the middle 3 wire lamp socket cutting the wire that proceeds to the rest of the string? I notice a fourth wire that seems to run the lenth of the set I am assuming this wire would also be cut. Between the newly cut wire off of the middle socket AND that fourth wire I would assume that is where the new plug would be added correct?

Now I have another question. Having two of those capped off sockets are there for a reason, so what ill effects would I be looking at if there is only one present on each string?

Since I am doing quite a bit of assuming here, I would like to know if everything I said here is correct before I start to cut into a brand new string of lights. If this works out as described, then this thread would have certainly cut my Christmas purchase costs in HALF.

I have another question I would like to throw here out of the blue. Is it possible to change high voltage LED strings to low voltage? I am finding it difficult to find multi conductor cable that is safe to use at 120volts AND uses stranded conductors. The closest I have come to this was a 7 conductor 18AWG thermostat cable Since I have a REN48LSD that uses 18volts for my DIYC-Floods, I am curious if the light strings could be converted to this voltage, then I only need to run a cat5 cable to each. But this also brings forth another question: Would the 25ct LED set created exceed the 400ma limitation of the REN48LSD's channel outputs? More than likely, yes?

Overall I just would like to know a little more how these LED lightsets are wired up and if I am 'assuming' correctly on how and where I should be dividing the set.