He also has a Sigineer 24V/6kW on the same bank for the well pump. They aren't connected in any other way. He didn't have sufficient PV to power that pump, but he can offset about 70% of it. When he'd run the pump for about an hour, it would draw the battery down even at peak PV and delay the time the battery hit absorption voltage (2X Outback FM-80), and sometimes 58.3Hz wouldn't happen. On other days when the pump wasn't ran, the Magnum would drop to 58.3Hz at the approximate time the battery hit absorption voltage and would stay at 58.3Hz for about 6-8 hours.
He's since installed a smaller pump (2hp) and enough PV to fully power the pump AND charge batteries, I don't know if it's still happening on pump days, and he doesn't know off the top of his head, so he's going to document it the next time he pumps (typically only 1-2 days/week). He expects it is because resetting clocks is a daily event.
I trust a kill-a-watt to report a frequency value. He actually has two. One in the pump house with the inverter and one in the kitchen. They are always in agreement. He's also confirmed it with a Klein CL800. I've confirmed it with my Fluke 116.
Microwave clock (2 year old Panasonic Inverter microwave). Oven clock. Bose clock radio - pretty much all the clocks in the kitchen.
Nothing else is affected. I get that it's not a big deal from that regard, but the inverter is operating outside of published specification for an unknown reason creating a noteworthy daily nuisance. Generally speaking, when I find something that is running outside of specification, I am not willing to consider that it is as reliable as it should be. This odd behavior may be indicative of a premature failure.
