On Tuesday 17 April 2018 06:49:34 Lester Caine wrote: > On 17/04/18 11:14, Chris Albertson wrote: > > If you are thinking about LED lighting, don't try and replace > > incandescent bulbs. That works and is what people do but if you are > > building from scratch yu design the LEDS into the architecture. > > I've replaced almost all the existing light bulbs with LED ones. The > best change was in the workshop where the fluorescent tubes are now > LED versions. Instant start and no flickering! But while fitting them > I began to wonder if now is the time the lighting circuits in the > house simply move to 12V DC? The kitchen has a number of 12V > transformers powering the lights. The LED bulbs are taking a 20th of > the power the original bulbs used so one power pack could power the > whole lot with power left over! But thinking about the 'off grid' > situation, a 12V battery with a low dropout regulator could provide > lights efficiently. While bigger appliances need 'mains', quite a > number around here are also 12V powered, so 'building from scratch' > could a DC supply direct off a storage system be an alternate way > forward?
i don't see why not, Lester. 12 or 24 volts would go a long ways toward keeping the NEC out of your hair. Insurance folks are stickier about such stuff, so I'd ask them if they had any special wireing rules for low voltage led lighting. The only thing that comes to my pre-coffee mind is the heavier wire the 12 volt stuff would need, whereas 24 could run on a gauge smaller, and 48 on really small wire. I would fuse it, using fuses of 150 to 200% of the leds draw though. Provided that was also under the wires textbook ampere capacity. I don't know if the NEC has addressed that yet. but I'd sure do some checking before I built a $100k house with all led lighting. My copy is now 20 years old, and that chapter wasn't even a twinkle in anybodies eyes then. I wonder if a google search might turn up something? Yes, quite a bit, for starters it must be class 2 compliant. And they draw a line at 30 volts. With separate 12 and 24 volt categories. This is probably the best starter reading: <https://www.elementalled.com/low-voltage-safety-understanding-class-2-compliance/> The language used is much closer to easily understood than the typical NEC edicts. -- Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
