___ Posted June 28, 2016 Share Posted June 28, 2016 Here's that paper I was forever looking for that explains the mathematical relation between voltage, impedance, and frequency, and how it is used to detect islanding. Not directly applicable here, just for the general edification of members. To know that a funny frequency generally points to something else... https://scholar.sun.ac.za/bitstream/handle/10019.1/1559/Hobbs, I.K.pdf?sequence=1 Mark 1 Quote Link to comment Share on other sites More sharing options...
Guest Posted June 28, 2016 Share Posted June 28, 2016 Dankie Plonkster. Quote Link to comment Share on other sites More sharing options...
maxomill Posted July 2, 2017 Share Posted July 2, 2017 we had a power outage last thurs (edenvale jhb ) night which took me 30 mins to realise because of the inverter. when the power came back on I noticed it has been hovering around the 240 area and not the regular 227v . anyway its back down now . Quote Link to comment Share on other sites More sharing options...
Sidewinder Posted July 2, 2017 Share Posted July 2, 2017 I received a SMS notification from Eskom (nogal) the other day (27th June) to advise of a power outage in Midrand Area from 22h00 till 06h00 the next morning for maintenance. I never noticed the switching, as I'm on a Infini, so I missed the whole thing Quote Link to comment Share on other sites More sharing options...
Sidewinder Posted July 2, 2017 Share Posted July 2, 2017 So, had a look at my EmonCMS, and found the outage. However, it started on Friday @ 10h10 till 11h20. Not quite what ESKOM said. Quote Link to comment Share on other sites More sharing options...
maxomill Posted July 2, 2017 Share Posted July 2, 2017 3 hours ago, Sidewinder said: EmonCMS sorry please update me on what that is . and yes I get it that its monitoring software . but prey do tell anyway cheers Quote Link to comment Share on other sites More sharing options...
SilverNodashi Posted July 2, 2017 Share Posted July 2, 2017 4 hours ago, Sidewinder said: I received a SMS notification from Eskom (nogal) the other day (27th June) to advise of a power outage in Midrand Area from 22h00 till 06h00 the next morning for maintenance. I never noticed the switching, as I'm on a Infini, so I missed the whole thing It's fun, isn't it? Our street also had downtime due to the municipality replacing old broken DB's with newer ones throughout the neighborhood. Some houses were without power for two days due to some cable fault - not sure what. Anyhow I decided to "lend" some free solar power to my neighbor so they could at least make coffee and the wife could operate her home business during the day. Such a nice feeling to know we have lights and power, even during planned outages. Gabriël and Chris Hobson 2 Quote Link to comment Share on other sites More sharing options...
Sidewinder Posted July 3, 2017 Share Posted July 3, 2017 Maxomill, From Google: Emoncms is a powerful open-source web-app for processing, logging and visualising energy, temperature and other environmental data. If you run an Axpert, one should also install ICC to control the Inverter, as it's poor SoC calc is legio. You can read many articles here on PF. (Specially ones on the BMV) Now if you run ICC, three little add-on to that is EMONCMS, MQTT & Node-Red. So EMONCMS enables you to report on all parameters of the Axpert. No need to "publish" or log to cloud service, just run the server as localhost. The Gridpower graph above was created in matter of seconds, as I did not have such a report before reading this posts. MQTT is a message broker, so you can exchange parameters to other devices, using a Node-Red program to control the actions. I can get the Pi temp and uptime report to my smartphone, by subscribing to my feeds on the pi (sitting behind firewall on private network) So, if you go to Manie's website (www.iccsoftware.co.za), and look at the download section, you will see some of these option for download. For newbies, I recommend to just download the complete image, which contains all the items mentioned here, in one package, thus no need to install and configure each item individually. One can test ICC for a month with a trial key, before buying the software for Windows or Pi (linux). PS, I don't get commission from Manie, but I highly recommend his software, specially on the Axpert models. I have a Infini now, and still use ICC for its overall ability to tell me what is /and has been going on on the system. So one of my projects for the future would be to get an alert when ESKOM goes down/up. Shouldn't be too difficult, just needs some time. ibiza, pilotfish and Chris Hobson 2 1 Quote Link to comment Share on other sites More sharing options...
Gabriël Posted June 16, 2018 Share Posted June 16, 2018 (edited) vredenburg grid down 20:02:08; vredenburg grid up again 20:53:43 Edited June 16, 2018 by gabriel xtra data Quote Link to comment Share on other sites More sharing options...
DeepBass9 Posted February 11, 2019 Share Posted February 11, 2019 (edited) I see Eskom is on Stage 4 load shedding today. That escalated quickly. I think there may be some sabotage by the unions for not being consulted on this Eskom split. Edited February 11, 2019 by DeepBass9 Quote Link to comment Share on other sites More sharing options...
SilverNodashi Posted February 11, 2019 Share Posted February 11, 2019 9 minutes ago, DeepBass9 said: I see Eskom is on Stage 4 load shedding today. That escalated quickly. I think there may be some sabotage by the unions for not being consulted on this Eskom split. Perhaps they're using this, lame excuse, to lure the masses into accepting their price increase soon? Quote Link to comment Share on other sites More sharing options...
DeepBass9 Posted February 11, 2019 Share Posted February 11, 2019 Probably. I only noticed because I went to the shop and all the lights were off. I have noticed though that MTN reception is particularly bad today. Maybe one of the towers went down, or the batteries can't take the power being off for so long. Quote Link to comment Share on other sites More sharing options...
SilverNodashi Posted February 11, 2019 Share Posted February 11, 2019 2 minutes ago, DeepBass9 said: Probably. I only noticed because I went to the shop and all the lights were off. I have noticed though that MTN reception is particularly bad today. Maybe one of the towers went down, or the batteries can't take the power being off for so long. And you only have two towers! Quote Link to comment Share on other sites More sharing options...
DeepBass9 Posted February 11, 2019 Share Posted February 11, 2019 Unfortunately yes. Quote Link to comment Share on other sites More sharing options...
Gabriël Posted February 11, 2019 Share Posted February 11, 2019 well the timing.... consider cr's much applauded sona - as soon as the euphoria died down the lights went out [literally]... also no big oilfields off mosselbaai, was all part of the buildup before the dark ages - its back to darkest africa... and still no word on the stolen oil reserves; bought by cr's bud at 30% off world market prices back in 2015... ok, some might say i'm in a pessimistic mood BUT i bask [or rather my pv's] in todays beautiful but windy weather and might have a little braai tonite, no, i can't complain thank you Quote Link to comment Share on other sites More sharing options...
Guest Posted February 11, 2019 Share Posted February 11, 2019 (edited) 1 hour ago, gabriel said: ... pessimistic mood ... For me the infrequent failures, all that is whatever. Everyone know knows how to deal with that now. The part that I'm watching is when it becomes a more permanent basis. That is what we must be pessimistic about. Edited February 11, 2019 by Guest Quote Link to comment Share on other sites More sharing options...
___ Posted February 11, 2019 Share Posted February 11, 2019 17 minutes ago, The Terrible Triplett said: The part that I'm watching is when it becomes a more permanent basis. I look at Nigeria, where it is pretty common to have multiple failures a day. Then I think of Zimbabwe where you pretty much have power half a day each week, or something like that. I don't consider Nigeria failed, but I do consider Zimbabwe to have failed in that respect. Quote Link to comment Share on other sites More sharing options...
Guest Posted February 11, 2019 Share Posted February 11, 2019 (edited) 15 minutes ago, plonkster said: ... Nigeria ... Zimbabwe ... Dude, do you see SA being able to run half a day on Eskom or on multiple failures each day, on a regular long term basis, like Zim / Nigeria? I don't. Not by any stretch of my immense imagination. A very select few can make a plan, prices of all goods will sky rocket, shop shelves will be empty, investment will fly out the country so fast our heads will spin .... and we will be dropped into junk status with all the ratings agencies. The Rand will be worthless, another failed African country. You cannot run a modern western society on iffy electricity. Nigeria / Zim can only get better from where they are ... we on the other hand will have to go down before we can "come back up". And lest not we forget, Zim is again on the brink, Nigeria, I quote a quick Googled BBC headline: Nigerian general election 2019 'Our minds are on starvation, not elections' Without electricity, the poor will become legion. Edited February 11, 2019 by Guest Quote Link to comment Share on other sites More sharing options...
___ Posted February 11, 2019 Share Posted February 11, 2019 3 hours ago, The Terrible Triplett said: The Rand will be worthless, another failed African country. Oh make no mistake, as I said in the past... getting out of here isn't too much of a problem anymore. Just selling the house might be a tad hard... But lets hope we don't have to go there... or if we do, that I'd have 6 good months of advance notice Have we reached the tipping point yet? Moodies doesn't seem to think so, having upgraded us from negative to stable a few weeks ago... but we'll maar have to see. Just like always. Quote Link to comment Share on other sites More sharing options...
Gabriël Posted February 11, 2019 Share Posted February 11, 2019 1 hour ago, plonkster said: that I'd have 6 good months of advance notice were getting it every day - depends on your standard, i.e. how 'bad' must it get.. Quote Link to comment Share on other sites More sharing options...
Gabriël Posted February 11, 2019 Share Posted February 11, 2019 5 hours ago, The Terrible Triplett said: it becomes a more permanent basis. what frequency would be 'more permanent basis'? Quote Link to comment Share on other sites More sharing options...
Mike Posted February 12, 2019 Share Posted February 12, 2019 5 hours ago, plonkster said: Oh make no mistake, as I said in the past... getting out of here isn't too much of a problem anymore. Just selling the house might be a tad hard... But lets hope we don't have to go there... or if we do, that I'd have 6 good months of advance notice Have we reached the tipping point yet? Moodies doesn't seem to think so, having upgraded us from negative to stable a few weeks ago... but we'll maar have to see. Just like always. I have had my home on the market now for 4 months, not one viewing, maybe a few enquiries.....even had our local elec engineer tell me tongue in cheeck, stage 4 would not have happened if i had not stopped sending my 1.2mw a month back to the grid. He said that no harm would come to the transformers as there were only 10 solar sites in our town..... Quote Link to comment Share on other sites More sharing options...
Guest Posted February 12, 2019 Share Posted February 12, 2019 8 hours ago, gabriel said: what frequency would be 'more permanent basis'? The previous rounds of blackouts forced a lot of small to medium businesses closures and forced a lot of larger business to go solar. So if we start going into stage 4 on a daily basis for months in a row, unless it is by design to fix things, we would be in dire straits. The two time I have deduced where I would start getting sick to the pit of my stomach is when: 1) Jhb, Cpt, Dbn, Bloem, PE all out at the same time. 2) When we see Aurora's in South Africa. Quote Link to comment Share on other sites More sharing options...
___ Posted February 12, 2019 Share Posted February 12, 2019 1 hour ago, The Terrible Triplett said: So if we start going into stage 4 on a daily basis for months in a row, unless it is by design to fix things, we would be in dire straits. Ted Blom says we're closer to a 20%-out-of-service number at the present moment. I would think that a 50% level is a clear pack-it-up-guys-we-had-a-good-run signal. So I tend to agree. Months of level-4 while things get worse and not better... that would be a sufficiently large red flag. Quote Link to comment Share on other sites More sharing options...
PJJ Posted February 12, 2019 Share Posted February 12, 2019 5 minutes ago, plonkster said: Ted Blom says we're closer to a 20%-out-of-service number at the present moment. I would think that a 50% level is a clear pack-it-up-guys-we-had-a-good-run signal. So I tend to agree. Months of level-4 while things get worse and not better... that would be a sufficiently large red flag. This whole when to leave thing reminds me of a book that was our prescribed book in Matric for Afrikaans (Die kwart-voor-sewe-lelie) Instead of missing my "Blom tydperk" I am afraid I will miss my "leaving comfortably" window As a side note, I hated that book with every fiber of my being. Quote Link to comment Share on other sites More sharing options...
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