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Tinker Guru Joined: 07/11/2007 Location: AustraliaPosts: 1904
Posted: 11:44am 13 Sep 2018
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Thanks for your suggestion Aaron. I will look at the volt meter next try. But these are 200Ah Lithium cells, 16 of them. They do not suddenly go to their knees like you might see with LA batteries. When I test big loads which might draw 150+ Amps from the bank the volt meter drops very slowly a volt or so. Naturally I do not have 150A charging available so that kind of testing can't be supported for long.
I'm more inclined its some electromagnetic interference.Klaus
Revlac Guru Joined: 31/12/2016 Location: AustraliaPosts: 1026
Posted: 11:52am 13 Sep 2018
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This was on 320Ah Lithium bank, and roasted the 200Amp fuses on each. Cheers Aaron Off The Grid
Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406
Posted: 08:28pm 13 Sep 2018
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Its crazy, but the only thing that I can think of is lowest outside temperatures around those times.
Closer to 5am could be very first light, and the solar controller fitfully cycling as it struggles to start up and get going.
Also Klaus's experience with two inverters running, could there be fast transients on the dc line ? Not a major voltage sag as such, because the battery would have a very low source impedance, but a transient or glitch on the dc ?
I dunno... But if the negative common side of the dc bounces, that might be getting get into the control system somehow ??
Cheers, Tony.
renewableMark Guru Joined: 09/12/2017 Location: AustraliaPosts: 1678
Posted: 11:03pm 13 Sep 2018
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I don't think it's the controller as it won't even start till it sees 40 watts and that is WAY WAY after 3-5am. I'm very suspicious of that heater creating emi, I'll see how it goes with filters on the switch cable, as it was such an infrequent marginal issue that may just be enough to solve it.Cheers Caveman Mark Off grid eastern Melb
Madness Guru Joined: 08/10/2011 Location: AustraliaPosts: 2498
Posted: 11:28pm 13 Sep 2018
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The controller will be attempting to start long before it actually starts charging. It will switch on as the panel voltage rises and then it will shut down and keep retrying till there is enough power then it will stay on.There are only 10 types of people in the world: those who understand binary, and those who don't.
Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406
Posted: 11:33pm 13 Sep 2018
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Could certainly be the heater, those fan heaters use a very crude bi-metallic temperature switch which could easily arc and spark and fart around.
One way to fix that might be to use a proper external room temperature controller, then plug the fan heater into that. Set the fan heater for flat out max temperature and then the controller will turn it on and off to control the room temperature.
The controller will have a relay that will switch very positively.Cheers, Tony.
Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406
Posted: 11:36pm 13 Sep 2018
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My system does that. Its really painful to watch it struggle to start up at sunrise, feel really sorry for the poor thing !
But a dodgy fan control is more likely the problem IMHO.Cheers, Tony.
wiseguy Guru Joined: 21/06/2018 Location: AustraliaPosts: 1156
Posted: 12:51am 14 Sep 2018
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As noise is one of the issues being discussed here I have looked at what is currently being done with a view to can it be done better. I think some worthwhile improvements for noise mitigation could result from very little effort and no extra components when using the QFP32/EG8010 adaptor board. If this has been raised in another post somewhere I missed it.
The environment of the inverter is electrically noisy and always will be.
The bottom of the adaptor board has a partial copper plane and pads for every pin to have an 0805 surface mount component added between the adjacent pin and the copper plane. I am confident that the designers intention was to bridge the pad for the appropriate ground pin of the IC to this plane to form a ground plane right under IC.
Other pins could also be bypassed to this "quiet" ground essentially right at the pins of the IC for best effect. So any pin of the EG8010 circuitry that has a HF capacitor to ground (anything less than 100nF) would benefit from it being a surface mount capacitor soldered to the provided pads on the underside of the adaptor board. I am unsure of further improvement gains by also tying the 2 isolated pads at the centre ends of the adaptor board ground plane connections to the lower PCB but I will be providing pads for this in my design.
It is also good engineering practice to keep the crystal legs as short as possible. To this end I would recommend removing the 2 pins that take the crystal leads onto the lower PCB altogether. I would solder the crystal with the leads as short as practicable directly into the vacant holes where those 2 pins were & and solder the two small xtal capacitors on the xtal pins to the SMD ground plane pads. Soldering 0805 capacitors on to the pads I reckon is easier than soldering the pins of the EG8010.
Lastly changing pull up or pull down values to mitigate noise on a sensitive pin is not really best engineering practice. If its meant to be high (or low) drive it in that direction, if possible with something gutsy like a buffer. Warps suggestion of an opto-coupler is a good plan and if I go that way I would use one with a digital output. The equivalent cost is around 1 output FET.
If at first you dont succeed, I suggest you avoid sky diving.... Cheers Mike
Tinker Guru Joined: 07/11/2007 Location: AustraliaPosts: 1904
Posted: 09:01am 14 Sep 2018
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So my 6KW inverter got the little relay mod today - no more brownouts.
Then I tried that sudden high load, on one inverter shutting down another but not the first one, thing and that is still happening. But strangely only one way.
If I reverse the roles of both inverters it never happens, no matter how hard I try.
For example: house and workshop load running on the 3KW inverter.
On the 6KW I connected about 4.2KW of heaters and then on top of that hit the chopsaw switch. No problem at all, both inverters kept on doing their job. Watching the battery volt meter, it did drop around 2 volts (54 - 52) or so briefly - hard to see the peak on digital meters. Wish I had some peak recording gear.
The Hall Amp meter shot up to 200Amps or so from the battery. That chop saw has a tremendous start up current - great for testing inverters . I kept that test short as most of the sunshine for today was past. Will try more load another sunny day.
These inverters really can take a hammering. And I think I fixed those odd re starts but time will tell. Having two inverters I will just connect them so the big one supplies all the house GPO power and the workshop/ shed. The smaller one will run the lights and also being my spare. All the wiring to do that is already there so its simple to swap their tasks if so required.
Klaus
Revlac Guru Joined: 31/12/2016 Location: AustraliaPosts: 1026
Posted: 11:12am 14 Sep 2018
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Klaus Thats impressive power, I would be more than happy to start/run the drop saw with other loads like that. This one is 2400w Hitachi, and it sure does take a big whack to start. I have run it with a 4Kw HF inverter, I'm pushing my luck a bit on that. After all you have thrown at your inverter and it and it has survived, I would be proud of that anyway. Cheers Aaron Off The Grid
renewableMark Guru Joined: 09/12/2017 Location: AustraliaPosts: 1678
Posted: 11:54am 14 Sep 2018
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It's very odd how your design and layout is prone to high load self restarts, I can run all sorts of crap with the Madinverter and start a 10 inch grinder or coumpound saw and compressor at the same time.... but at friggin 3-5am mine restarts while on pissy loads. grrrrr frigga grrrr.Cheers Caveman Mark Off grid eastern Melb
Tinker Guru Joined: 07/11/2007 Location: AustraliaPosts: 1904
Posted: 03:26pm 14 Sep 2018
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Not any more Mark
Perhaps yours suffers from morning sickness .
Just keep at it, you figure it out eventually. These things are obviously sensitive to layout. But when working they are hard to beat.Klaus
Notice. New forum software under development. It's going to miss a few functions and look a bit ugly for a while, but I'm working on it full time now as the old forum was too unstable. Couple days, all good. If you notice any issues, please contact me.
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