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self consumption power or power drain in system?

Hogheavenfarm

Regulation Stifles Innovation
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Jun 24, 2022
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Hello, Over the past few days I have noticed a strange (to me) occurrence. I have just installed a Epever Tracer 6415 AN controller and an MT-50 remote programming unit with it. It is hooked to 740w of panels (for now) and charges two 12v renogy AGM batteries in series., 24v.
Since it has been cloudy and rainy, I have been watching the displays carefully, and noticed that even in full darkness, both displays (on the SCC and the remote unit) show power being sent to a "load" (the lightbulb icon is lit). The voltage supplied to the "load" is battery SOC, and the amps read 0.8a every third cycle. As the display cycles through various parameters I noticed about every 10 or 15 seconds it displays the "0.8a" and the rest of the time it displays "0.0a".
I looked up the self consumption values and the SCC should be using 60 milliamps, and the remote uses 15 milliamps, so way below what I am seeing being used. There are no loads at all hooked to the system yet, no connections to the inverter or even the shunt or meters. The "manual load control" on the MT-50 indicates that it is "OFF". Turning the panels off does not affect this drain.
Any ideas where I should look? Or is this "normal"? I would think the "load" should be off and displaying nothing going anywhere, it doesnt seem logical that it would be reporting self consumption as a "load" either.
 
Only thing I think I can do at this point is do a "system reset" and see what happens. I only noticed this yesterday, but the system has been running since last Sunday, so I think it wasn't doing this before then.
 
The voltage supplied to the "load" is battery SOC, and the amps read 0.8a every third cycle. As the display cycles through various parameters I noticed about every 10 or 15 seconds it displays the "0.8a" and the rest of the time it displays "0.0a".
It does sound unusual.

If you are looking for something to probe, i'd put a volt meter on the load terminals to see if that fluctuated. Similarly, if you have a clamp meter, i'd see if there is any current flowing between the SCC and battery and whether that amount varies, particularly at your 10 or 15 second interval.

If you are looking for something to read or consolation knowing you are not alone:
 
Ok, thanks, I can do that tonite. I didn't think to verify it with the meters since it appeared on both devices.
I wasn't aware there were any issues with these, so I will read up on that.
 
OK, quick test results - a pic and better explanation tomorrow - The big battery wires are showing current between 0.2 and 0.8 amps going to a "load", both positive and negative lines. This continues even past the 200 amp breakers and follows these lines all the way to the inverter. There are 200 amp breakers on both positive and negative sides, they are both "off". The inverter is also "off". There is no voltage showing up when I test the poles of the breakers though, shunt also shows no voltage. I did notice that since there is a full moon tonite, the panels were showing 2 volts, and the amp cycling stopped, although the "load" voltage remained the battery voltage. The MT-50 display shows this, but the SCC display never shows any amps, but does indicate that voltage is supplied to a "load". My first thought was leakage around the breakers was charging the caps in the inverter, but no voltage is showing in those lines.
Not an electrical guy so I am pretty confused. SOC is dropping fairly quickly, was 27.2 at 4:30pm, was 26.6v at 6pm, now 7pm it is 26.2v,according to the displays, my voltmeter shows 26.17v , surface charge?
 
There are no loads at all hooked to the system yet, no connections to the inverter or even the shunt or meters.
The inverter is also "off".
So the inverter and shunt and the meters are connected after all?

I'm not sure this explains the voltage drop you are seeing. There is inverter self consumption and of course battery self discharge. The self discharge should be stated (hopefully accurately). The battery self discharge can be observed when disconnected from everything (really disconnected) - who knows, maybe the batteries are simply not holding a charge on their own?
 
All connections are made, but there are disconnects on both sides of the battery (exporting) side. Beyond those are the shunt and inverter. I am only running the SCC and the remote control meter and have PV in and charging the batteries.
I think I have inadvertently solved this though, I just finished playing around some more with the remote control and the SCC. The manual implies that the remote settings will override the SCC panel settings, which is sensible for a remote where you cannot reach the SCC itself. I repeated tried to turn the "manual load" to "off", which the remote shows to be "off". After trying the SCC panel itself, I was able to actually turn the "manual load" setting to "off", and the remote immediately stopped cycling. It had been cycling from zero amps to 0.8 - 1.0amps every 35 seconds, with 0.2 amps appearing halfway between the big cycles. The lightbulb icon is now off.
I must have hit it accidentally when programming the battery type to "GEL" on Wednesday.
Please consider this issue solved, and thanks for the help that sent me looking again.
 
turn the "manual load" setting to "off", and the remote immediately stopped cycling. It had been cycling from zero amps to 0.8 - 1.0amps every 35 seconds, with 0.2 amps appearing halfway between the big cycles. The lightbulb icon is now off.
This is behavior I have seen over several Epever SCCs. They do not compute well when the load terminals are turned ‘on’ when there is no load present. While I hesitate to call it “normal” I would describe it as typical.
 
Thanks, I can attribute this to my fat fingers and poor eyesight I think. I had no reason (or load) to turn on, so now that its corrected I think I will keep my fingers off the programming!
 
This is behavior I have seen over several Epever SCCs. They do not compute well when the load terminals are turned ‘on’ when there is no load present. While I hesitate to call it “normal” I would describe it as typical.
I would often leave load on with no load attached at night to avoid the high pitched buzzing sound they make.
 
Mine is dead quiet also, but not running any loads yet, so we will have to see. Still in the tweaking phase.
 
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