I agree with Phil here. I think that sleep mode, and/or wiring up special circuits for a small inverter, is a thing of the past with full-time residences. With PV prices so low, it's much better to just add more charging capacity than going through all that trouble and complexity. Part-time residences, boats, and RVs are a different story.
That doesn't mean that you should ignore phantom loads. I still use lots of switchable plug strips. Just leave one of the main inverters on, add a little more PV, and don't worry. You may need to run a genny a little bit more in the winter, but that's still easier than doing a separate inverter system, especially for customers who are not Wrenches. Brian Teitelbaum AEE Solar From: [email protected] [mailto:[email protected]] On Behalf Of Phil Undercuffler Sent: Tuesday, May 11, 2010 3:36 PM To: RE-wrenches Subject: Re: [RE-wrenches] Tiny load problem If the normal connected loads are within the capacity of a single inverter (which may actually be possible -- I run my whole house off one Outback FX2024, microwave, dishwasher, washing machine and all) then you can just leave one of the inverters in sleep mode or disable output but leave input/charging enabled. Which inverters are you planning on using for the generator charging? Depending upon which brand or how sophisticated you want to be, there are a couple ways to skin this cat. Easiest and cheapest is to simply not connect up any AC output wiring or stacking cables to the second inverter, and program it to stay asleep and charge only when it sees AC input power. I used to be religious about making sure my inverter was asleep, and even had a second baby inverter to power a handful of full time or sensitive loads. However, it got difficult trying to explain why you couldn't just plug the vacuum cleaner into just-any-old-outlet, and as my electronic widget count expanded it became less and less advantageous to have that baby inverter. Phil Undercuffler Conergy On Tue, May 11, 2010 at 9:58 AM, bob <[email protected]<mailto:[email protected]>> wrote: I am sizing a system that will have dual inverters to shorten generator charging in the winter and enough solar to charge the rest of the time. Here's the problem, the inverter will not be able to get into sleep mode at night. There are 2 cell chargers and a "cpap" machine having to run all night. It only totals 26 watts, has anyone found a better way to do this without having to keep an inverter awake to produce 26 watts? I would like to dedicate a Morningstar 300 watt inverter for the job but the system is 24 volts and Morningstar has no plans to make one in 24 volts. Anyone got any other ideas, or am I best to just deal with it? Thanks, Bob
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