So at higher loads even w/out that little AC Unit, the problem would still crop up intermittently. Am I the only one who stares at SA screens for hours??
So I added a snubber filter to my large 250v AC unit across both poles. No change.
Last night I woke up a 2 AM and realized that this whole time it could be my ancient whole house swamp cooler. The AC motor on that thing only draws about 400w but its an absolutely raw inductive load kind of like a generator in a 100 year old Model T.
Turning it OFF solves the problem, so that was it. But I have plenty of power to run it, so I put another snubber filter on it and amazingly, that solved the problem! In fact, I've never had over 7500 watts of sustained PV power before now. Today I'm getting sustained ~8500w for long periods of time, if only the damn clouds would go away. The swap cooler runs 24/7 during summer, so It's always been in the picture since I put the system in. And likely why I've not been getting the full potential of this system until today.
View attachment 159133
So, just in case someone else has this same problem, here goes.
A snubber filter circuit dampens unwanted frequencies from inductive loads like AC motors (fans, AC units, etc) and prevents them from interfering with the solar inverter's AC voltage regulation/feedback mechanisms.
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Mine is simple RC filter of 2.5uf/350VAC non-polarized cap (like they use in fan startup motors) and a 10ohm/10w resistor in series put directly across the AC line:
L1 & L2
Neutral
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So I use two of these filter circuits, one wired across each phase/120v line near the source of the noise.
You can get the caps on Amazon
https://www.amazon.com/dp/B0BGR3Y8TN?psc=1&ref=ppx_yo2ov_dt_b_product_details
And the resistors:
https://www.amazon.com/dp/B07PK1KTZB?psc=1&ref=ppx_yo2ov_dt_b_product_details
Now I'm finally going to really see my electric bill DROP.
Jeff
