The problem is you need a minimum conductor size for low-power circuits just to ensure mechanical stability of the wire. I've seen many OEMs going thinner and thinner on signal wires, and they are super easy to break if you yank on them at connectors, etc. Be very careful disconnecting connectors with these super thin wires, and don't put stress on the conductors.
On Sat, Oct 5, 2024 at 8:48 PM Cor van de Water via EV <ev@lists.evdl.org> wrote: > Note that if you want to save on copper and are only interested in > delivering the same power with the same percentage of wire losses, then > going 4 times up in voltages allows you 16 (!) times smaller wire surface > area, because current is 1/4 but also 4 Volt loss in a 48V system is the > same percentage as 1V in a 12V car. So if you needed a 1/4" diameter wire > (2 AWG) in a 12V car then you only need 1/16" diameter wire (14 AWG) for > 48V to transport the same power with the same losses. > In different words: going up 4 times in voltage means you only need 6% of > the copper for the same performance. > Now you may get why distribution lines are so high voltage. > Cor. > > On Sat, Oct 5, 2024, 6:50 PM Lee Hart via EV <ev@lists.evdl.org> wrote: > > > >> On aircraft, 28 volts (24 volts) has been the standard low voltage > > forever. > > >> It is the standard on specialized military vehicles and equipment as > > well. > > > > Also in large trucks and buses. > > > > > "42 volts" is the threshold for "low voltage" in the US National > > Electrical > > > Code, but as I recall, that is for AC rather than DC. > > > > Yes, also UL and ETL. They specify 30vac or 42vdc peak as the maximum > safe > > limit for voltages you can touch. > > > > > I suppose if you are going to make a departure from the industry > > > standard of 12 volts, then why not go all the way to 48 volts. > > > > 48v actually exceeds the "low voltage" classification for NEC, UL, and > ETl > > etc. There is also a problem with arcing. Switch, relay contacts, fuses, > > circuit breakers, motor brushes, etc. are all typically limited to 30vdc > > max before arcing will not extinguish itself. > > > > To me, it makes more sense to increase vehicles from 12v to 24v, in line > > with a huge number of other vehicles. There are already lots of 24v > > accessories. Going to 48v means essentially no standard components or > > accessories can be used. > > > > That said... The auto companies routinely ignore electrical safety > > standards. They use undersized wire gauges, combustible wire insulation > > that melts at lower temperatures, inadequate fuses, switches and relays, > > etc. > > > > Lee > > -- > > Excellence does not require perfection. -- Henry James > > But it *does* require attention to detail! -- Lee Hart > > -- > > Lee A. Hart https://www.sunrise-ev.com > > > > > > _______________________________________________ > > Address messages to ev@lists.evdl.org > > No other addresses in TO and CC fields > > HELP: http://www.evdl.org/help/ > > > > > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: < > http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20241005/991da995/attachment.htm > > > _______________________________________________ > Address messages to ev@lists.evdl.org > No other addresses in TO and CC fields > HELP: http://www.evdl.org/help/ > > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20241006/a3a77a38/attachment.htm> _______________________________________________ Address messages to ev@lists.evdl.org No other addresses in TO and CC fields HELP: http://www.evdl.org/help/
