[RE-wrenches] Sunny Island retrofit

[Mac Lewis]

Hello wrenches,

I wanted to run this scenario by the forum.  I have spoken with SMA about
this, but want some other opinions.

We were recently contracted by a fellow solar company to do some warranty
work for them out of town on a Sunny Island system that they had installed
about 5 years ago.  It was VERY poorly implemented originally and was never
installed as SMA intended.  In fact, during a small power outage, the only
loads that never came back on after the utility was back on line were the
loads in the critical load panel.  Oops.

Anyway, our job is to get it working properly for the least amount of cost
possible.  They have a Fronius IG Plus 10.0 fed into a 400A service panel.
 The Sunny Island 5048 AC Input also comes off of this panel and feeding a
120V only critical load panel.  Please note that there is no solar fed into
the AC output side of the Sunny Island, because there is not 120/240
available and thus there is no possible way for this system to utilize the
solar while the grid is not present.

I see two options (but there may be more): pull out Fronius, put in Sunny
Boy inverters and an autoformer, wire properly.  Another option is to add
second Sunny Island and try to AC couple the Fronius with the two Sunny
Islands.  The second option is less expensive overall, but I'm hesitant to
rely on AC coupling with the Fronius.

I'd appreciate any thoughts on this.

Thanks





-- 



Mac Lewis

*"Yo solo sé que no sé nada." -Sócrates*
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