Christmas lights can be a beautiful sight to behold. They can decorate public spaces and homes.
Stringing lights outside can be a real safety hazard if you’re not careful. For outdoors use the lights you need to have lights that are designed to be used outdoors.
For outside use there are nowadays both consumer and professional LED light systems – and they are quite different how they are built.
I have made a write-up on quite safe consumer LED lights at https://www.epanorama.net/newepa/2018/11/20/christmas-lights-technology/ where Big Clive shows a dangerous example at More dangerous Xmas lights from eBay with fake fuse! video.
LED lights used in big professional installations are different than consumer products. These are the strings of lights often used on city centre trees, either wrapped round the branches of ordinary trees or strung seasonally on big Christmas trees. Stuff like this tends to have a rough life, with extreme weather exposure and frequent installation and removal by people who often don’t treat them too well.
The difference in price and construction between home and professional Christmas lights is huge. Big Clive video The construction and wiring of professional LED strings that shows how those professional LED lights work.
The lights are usually available in white, black or green rubber, with black being a preferred choice. The use of a high voltage DC bus allows a lot to be run end to end, but you have to be careful to ensure that the sealing o-rings are in place in the connectors.