>> 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 [email protected] No other addresses in TO and CC fields HELP: http://www.evdl.org/help/
