Grid-Tie Inverters with Batteries [RE-wrenches]

[Bill Brooks]

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Todd,

I believe that the standard for UPS transfer times is less than 1 cycle 16.7
ms. I'm pretty sure that many do it in an average of half that time.
Anything higher (up to 20 cycles) we might call "like a UPS". No PV inverter
that I know of is a true UPS. I think the fastest a SW can transfer is 2-3
cycles (32-48ms) and higher depending on the load and when it senses the
interruption. Many computer power supplies can handle outages of up to 20
cycles, depending on what they are doing at the time (power draw). The holy
grail is to get transfers for PV inverters into the half-cycle range, but
that may mean that you make your equipment so sensitive, that it is always
switching to backup even with a small transient. It depends on the
application and how desperate you are to not lose data or power. A high
quality UPS is still a good idea, even with a battery-backed system, if you
have a very critical application.

Bill.

Snip******

Maybe the Outback guys will remember what the switchover time is with the
SW's,
since once again xantrex is silent. I'd say if it is less than 10 ms it is
too
slow to be considered a reliable UPS source.

Todd


"Steve Bell, Sunwize Technologies" wrote:

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