Will get back on track eventually, but I was inspired by the mains stability plot to look at my data. I have nearly 13 years of data from my PV system and did a histogram of the daily averages - so far just for frequency. [image: distribution of daily averages.png] Curious - almost always below 50.0. I can remember some years ago readiing that the mains frequency was always manipulated to reach a daiily average of 50.000 Hz, in part so that old style clocks would run accurately. So, what's happening here? It seems unlikely that my inverter gets such a simple measurement wrong, so is the correction no longer applied, or is it simply that the corrections are made when the power system is at lowest load and my inverter is offline?
So as not to be totally off-thread, I'll mention my system. I have my weather devices connected directly to an home server based on an Intel desktop, with a Raid-5 array. I built this in 2010 from three WD black drives and when they had accumulated 10 years of run-time I decided to retire them. I tossed up going to SSD, but decided on WD Reds. After building and copying the new array I then discovered they were the (unspecified) shingled drives. Still, they came with a 3-year warranty, so I thought I'd see how they went. All good when I tested nearing the 3 years, and 3 months later the first one collapsed dramatically. Out they went, to be replaced by SSDs. The reduced power consumption should more than make up for the cost difference - assuming they last a reasonable time. I don't recall any unexpected shutdowns since 2011, so never thought of using a UPS, but I acquired one recently, so thought I'd connect it up. I invoked the gods of irony upon myself, by deciding to first test out the Linux drivers for the UPS, before plugging the server into the UPS power. I'd run out of USB ports on the server, so unplugged the mouse that is never used, plugged in the USB cable to the UPS and the server instantly started rebooting. On Wednesday 15 May 2024 at 3:22:24 pm UTC+10 Karen K wrote: > michael.k...@gmx.at schrieb am Samstag, 24. Februar 2024 um 08:20:17 > UTC+1: > > Also, we have super stable power supply here. Often years without power > surge, the last black some years ago, and this only locally. > > > Off-topic-comment: That's interesting. The situation at our region is > quite less stable. The voltage jumps up and down, and the frequency is > decreasing actually. > > [image: netzspannung-8.png] > > [image: netzfrequenz.png] > -- You received this message because you are subscribed to the Google Groups "weewx-user" group. To unsubscribe from this group and stop receiving emails from it, send an email to weewx-user+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/weewx-user/9f9b6d3f-bf73-4ef2-95a7-25fc112860b5n%40googlegroups.com.
