On 26.05.19 13:07, Dave Cole wrote: > There are some good reasons to use a 24 or 48 volt DC bus power system for > smaller systems. > The chance of electrocution is pretty low for a 48 volt DC system in a dry > environment. > Once you get above 50 volts or so things change.
Here in Oz, a "suitably qualified person" can wire ELV (Extra Low Voltage, <60 Vdc), AIUI. My feeling is that knowledge of fusing requirements for very low source impedance battery systems ought to also be a prerequisite. A house fire is an expensive lesson. > 24 volts is quite a practical voltage level for smaller systems. I'll be running 24v for LED lighting. As for power, you'll only find low power inverters, due to the losses. > Do a search for 24 volt inverters and you will find many. 48 volt, not as > many. Ah, then you're looking at 4WD/camping/holiday type suppliers. The 3 or 5 or 8 kW inverters I've read up on are all 48v, and I've not found one at 24v. > I'm thinking hunting cabin, small cottage, larger boat, remote shed, etc. Had begun to figure that. ;-) > Now if you want to do your entire house and have typical house loads it > seems like a 120V+ DC bus system would make more sense. Theoretically, yes, an inverter would then also have less I²R losses than at 48v. And there are 120v inverters - but only with integral system battery, in my searches so far. Most of the generic system components for a full household are at the industry standard voltage of 48v - inverters and batteries. I think there's a 72 Vdc inverter hiding out there in the marketplace somewhere. That might be theoretically attractive, but a good European 48 Vdc to 220 Vac inverter will be 96 to 97% efficient, according to the spec sheets I've read, so the battery inconvenience seems hardly worth any (half) percent you'd win. Erik _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
