Load-shedding extended - from 09h00 Tuesday to 05h00 Saturday

pinball wizard

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Feb 9, 2010
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29,528
But electrical stuff, its my trade, did it before I changed careers to IT.
I don't have a permit anymore to alter electrical installations and/or issue CoC, as I haven't done that kind of work in yonks.

What I do know for a fact is:
1. Eskom lies, and lies a lot
2. My own systems work, and they work well, the batteries are dying due to age
3. I complain because this is short of treason what is being done to my country of birth
I like it when people with actual knowledge share it. Much better than the cesspool in other parts of the internets.
 

ebendl

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Sep 27, 2004
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4,502
Eskom (and other sources) told me that mains frequency is an indication of load, the further it slips below 50Hz is an indication of system constraint. You can buy relays that will disconnect load when the frequency slips.

Ripple (geyser control relays) the electronic ones are designed to disconnect the load if the frequency goes below 48Hz

My power comes from Koeberg, so a low mains frequency tells me that the unit that is operational, is running at ABSOLUTE MAX FULL LOAD

From Wikipedia:
Mine has not fallen below 49.8 Hz during the last two days, except for the two periods where we had loadshedding (where it went to 0 :unsure: ).

So you might say Koebert is constrained but I'm not sure it indicates the national grid.
 

Lupus

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Apr 25, 2006
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Mine has not fallen below 49.8 Hz during the last two days, except for the two periods where we had loadshedding.

So you might say Koebert is constrained but I'm not sure it indicates the national grid.
Yup that's what I was pointing out, the frequency in some areas can be low while it can be fine in other areas. You cannot indicate that there is an issue because yours is low. I used to think that low voltage was an indication, but sadly before load shedding kicked in mine was still sitting at 234.
 

PaulMurkin

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Jan 31, 2020
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While the national grid is synchronized, there will be areas on a particular generator that will experience slip. This is what causes the generators to trip, Eskom won't tell you the whole story but I suspect the demand is just too much, and the generators slow down under the load and then get disconnected by means of a trip.

Every time, without fail, my frequency indication has shown that loadshedding was imminent. The instrument at first (inverter) I assumed was talking crap, but the last time we had loadshedding on the weekend I could hear my fan spun marginally faster on the inverter as opposed to the wall socket. That's because its an AC motor whose speed is synchronous with the mains frequency. Many people think the higher or lower the voltage the faster or slower an AC motor turns... that's true for DC motors... NOT for AC induction motors.

I also measured it this morning with a bona fide frequency counter. Frequency is low, and that's to be expected. I just can't help but put aside my spidey senses that we will be having Stage 4 before the week is over
 

TangoSA

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Apr 5, 2013
Messages
62
Guaranteed we'll have no blackouts on 1 November, 'Ek's dom' will pull a rabbit out of a hat!
 

PaulMurkin

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Jan 31, 2020
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Guaranteed we'll have no blackouts on 1 November, 'Ek's dom' will pull a rabbit out of a hat!
Guaranteed hence I will make the most of that day, and do as much work as I can. They will pull the same rabbit out as they have done in recent past when Ramatosspot has had the need to reprimand the comrades
 

Neuk_

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Jan 23, 2018
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Arg :confused: The weather isn't playing ball either so our batteries are staying at 100% SOC.
 

wingnut771

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Joined
Feb 15, 2011
Messages
15,182
20amp Solar Charger (R2k)
Hubble S100 (R4,4k)
1Kw Pure Sinewave invertor (R5k)
Automatic Change over switch (R1k)

Total R13k+ (Excluding install) and all your lights, alarm systems, and connectivity have an almost indefinite power supply during load shedding. With the automatic change over switch I don't even get off the couch. During the day you can run your laptops, TV and Freezer if needed. Keeping the lights on doesn't have to cost you an arm and a leg. I know this is not possible for everyone, but if you can, it makes life so much easier during load shedding.

This is just an example of the system I started on. I did have to replace all lights with LED's, but this was gradual and probably only added another R1k. We were already using a gas for cooking so that helped as well.

Add a larger Charge controller, and more batteries and life gets a little better, or just keep the lights on and add a parallel grid tie system (no batteries, and no feedback), and show the middle finger to Eskom.
You need 2 batteries for 24V.

Here is an all in one with double the power and built in 40A mppt.
 

Brian_G

Executive Member
Joined
Feb 7, 2020
Messages
8,071
Nope you might've been one of the lucky few, I know block 2 in Johannesburg didn't get hit, but somehow they generally do miss a few. Whereas block 11 has missed none and in fact get hit when it's not even load shedding.

So far nothing has happened in our part of block 9 of Jo'burg, and nothing scheduled for next 24 hrs.
 
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