Just one more Xmas light video.
Added 2020-12-21 12:58:29 +0000 UTCChristmas has arrived far too fast this year, so I'll probably have to release this video later this week.
It's a laid back look at the construction and wiring involved in the professional LED lights used on municipal trees and lamp post mounted frames.
Comments
If a common failure mode is severed cable, an exposed conductor could make contact with the tree. Assuming the tree isn't a terrific Earth, this strongly suggests the need for appropriate RCD protection. Type A would be best although AC should probably still work if there is enough leakage. I tested a Wylex WRS100/2 which is an AC-only RCD. Trip sensitivity with AC leakage was 24mA and with pulsating DC was 90mA. Both figures RMS calculated over full mains cycles. But even with a Type A breaker, it will depend where the break is in the LED string how much leakage you get. So it's a toss-up between the tree's resistance to Earth and whoever happens to be touching it. You better hope the tree is significantly better earthed than you are.
Mike Page
2020-12-23 21:33:15 +0000 UTCThey are harder to get hold of than the usual lights, due to being aimed at professional installers. You may need able to find local sellers on eBay selling them, but generally they have to be bought from specialist suppliers.
Big Clive
2020-12-23 16:06:31 +0000 UTCWhere can I get them from and what are they called? Look so much better than the ones I usually use
2020-12-23 00:09:07 +0000 UTCIs HO5/7 better than the blue Arctic cable ? (for general use, not lights in particular)
adrian
2020-12-21 22:44:24 +0000 UTCThat would be true with a smoothing capacitor, although to my knowledge, these just have a rectifier alone.
2020-12-21 19:45:07 +0000 UTCA really interesting video, however I am a little confused about the rectified voltage- Surely it is about 350volts DC - or am I missing something really simple and just having a "senior" moment ( I get lots these days) You have certainly de-mystified the wiring system of these 3 wire sets of Crimbo lights though. Thanks again for another brilliant video of how stuff works- Best channel on YouTube for this by far!
Mike Hughes
2020-12-21 16:54:58 +0000 UTCCan’t have too many of these ! Yes HO5/7 works well outside and in general wear / abuse environments, clever how the voltage is balanced in the coloured string. Much better quality but as you say you pay for it.
RDM
2020-12-21 13:32:09 +0000 UTCNever too many Christmas light videos, but then again I'm a fan...
Michael Thompson
2020-12-21 13:06:29 +0000 UTC
