[RE-wrenches] Outback efficiency?

[jay peltz]

Hi Ray,

#1, I don't see any improvement. But then I find it rarely used anymore with many small loads ( cell phone chargers etc), coupled with cyclic loads and 4 watt LED's etc.
Its got to be a really small system to have this be active.
I find that if people really want to use this that I'll wire up the remote on/off and they can use that from their bed at night.

#2.  It depends on how they measure the efficiency.  Since the no load is around 20 watts, if you have a 20 watt load, that makes a efficiency of like 50%, not including the inverter loss's of 6-10% which isn't really helpful in any sort of calculations.
I usually use 90% ish ( I think they publish 94% as peak eff.)  as my INV design efficiency ( sometimes it'll be lower, sometimes higher), and then add in the idle watts x 24 hrs day.

Hope this helps,

jay

peltz power

On Aug 18, 2013, at 3:01 PM, Ray Walters wrote:

> I have a couple of Outback questions.  On my load analysis sheet, I include 20 w x 24hr/ day for the inverter's no load draw.
> In the past I had very poor luck with the search mode on most inverters, and found that when I adjusted it so that it came on with efficient lighting, that the no load draw was still 15 watts.  I've just taken to disabling search mode, and add more modules.
> So question 1: has the search mode been improved in the past 5 years?
> question 2:  Is the no load draw most of the efficiency losses, so could I set inverter total efficiency to say 98%, while keeping the 480 wh/ day  inverter draw?  I don't want to overstate or understate the inverter losses.
> 
> Thanks,
> 
> -- 
> R.Ray Walters
> CTO, Solarray, Inc
> Nabcep Certified PV Installer,
> Licensed Master Electrician
> Solar Design Engineer
> 303 505-8760
> 
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