On Sun, 07 Nov 2010 00:53:11 -0700 "Michael C. Robinson" <plu...@robinson-west.com> dijo:
>Essentially, I want to build a very simple UPS. Charge batteries and >feed AC power to the rest of the circuit when the power is on. When >there is a blackout, power the rest of the circuit (not the breaker >box please) using stored DC power and an inverter(s). A generator and a medium size UPS will provide longer run time at less cost. I have an electric start Generac 5500 watt generator that will run for 13 hours on five gallons of gas. At the first hint of snow I go to the gas station and fill up four five gallon cans, plus the car. The car holds another 18 gallons, which can be siphoned if necessary. That's enough for three days. To back up the computers I have a moderately heavy duty APC battery UPS. It is sufficient to run the laptop for several hours, or both the desktop and the laptop for half an hour. All the computer and electronic stuff runs off it, including the router, cable modem and even the stereo. If the power goes out I do nothing for 15 minutes because most power outages are less than that. At 15 minutes I fire up the generator and plug the APC into it. You don't want to run computers off a generator (although I have done so), but the APC conditions the power. After several hours of power outage I run an additional 20 amp extension cord off the generator through a hole in the garage wall into the house. To this I connect the refrigerator, freezer, television and half a dozen table lamps. Now the power can stay out for several days and I'm still fine. The APC cost me $150 or so. The Generac cost me $450 used but almost brand new. It's noisy, but has a good reputation for reliability. It has a recoil starter in case its starter battery goes flat. It's way overkill for the computers and electronics, but its additional capacity is handy for other appliances during an extended outage. I have a gas fireplace that heats the house and requires no electricity, but the Generac also has enough to run a furnace if you need that. I don't need any fancy electronics or expensive devices to connect the generator to the entrance panel. My backup system is completely off the grid. When the power comes back on I shut down the generator and plug everything back into the wall outlets. _______________________________________________ PLUG mailing list PLUG@lists.pdxlinux.org http://lists.pdxlinux.org/mailman/listinfo/plug
