If you do it now, with no pv available it might be easier to test, no?
Looking for a schematic for Growatt MIN series of inverters for repair
- Thread starter lapsmith
- Start date
I'm assuming the grid breaker is disconnected so no chance of backfeed?
I tried it and the only difference was that the real time data screen shows off grid instead of standby. The voltage on the off grid terminals is still 0 and it is 240 on the grid terminals.
Correct. I misspoke earlier. I wasn't worried about backfeeding during the test since the breaker would be off. It would only be a problem if I left it hat way and there was an outage.
MajicDiver
Solar Enthusiast
Southeast Tennessee. Do have a lot of battery capacity - I lay that all out in my profile.
We have mini splits we use for heat, then we still have an older seldom used central heat/ac system that has propane heat - we use that when batteries get low during cold periods and cloudy days. We had several days of <10 degrees this winter and used propane a lot more than I would like, so I’m installing more panels because they are really cheap now.
We would not have made it thru late December and early January off grid without the propane system. But we still saved > $1,000 on propane as compared to winter before solar.
MajicDiver
Solar Enthusiast
That’s weird. To make sure I understand what you are saying: with PV available if you open the grid breaker the app shows the inverter in standby. But if you open the grid breaker with PV unavailable the app shows the inverter in off grid mode?
MajicDiver
Solar Enthusiast
I assume you left the grid breaker off a substantial amount of time? When I do that it takes about 2 minutes for the inverter to drain capacitors and power off.
MajicDiver
Solar Enthusiast
Also, every time Growatt loaded new firmware on mine I had to completely power off the inverter then back on for stuff to work right - I realized that, they didn’t tell me
MajicDiver
Solar Enthusiast
Something is wrong then. If that is the case the ATS would not work (if connected) because in an outage it would not transfer because it would not see grid go away.
In earlier threads you discussed connecting a generator I seem to recall.
Are you absolutely certain you are actually removing all external ac sources when you test? Have you tried lifting the grid input wires at the inverter and see if the same thing happens?
Something weird is wrong.
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MajicDiver
Solar Enthusiast
One time I was playing with battery settings and ended up sending 5kW to the grid for almost an hour before I realized what I had done, never heard a peep from distributor- it showed up in my usage chart on their app and of course it was billed.
MajicDiver
Solar Enthusiast
I just checked mine, when the inverter is in off grid mode the grid tied input terminals are dead, no voltage whatsoever.
I assume you have noticed the pre-wired terminal on the right? There are actually 6 terminals not five. Is it possible you are getting off one when checking voltage?
MajicDiver
Solar Enthusiast
See attached photo - with grid connected and batteries connected and batteries in “solar only backup” mode, the backup output is always live.
Separately, if I unplug the battery communication cable with or without PV the backup output goes dead.
So, that tells you that if they are not handling the battery communication to the LG battery correctly it could impact the backup output.
Attachments
Sorry for the confusion. It was night time (maybe too late to be messing with this stuff) so no PV. I enabled off grid as a test and when I switched the grid breaker off, the real time data screen showed off grid. However, the voltages were as noted.
Yes. I've seen where it takes a few minutes for the inverter to power down when everything is off, but with the battery still on, the inverter stayed on for as long as I was changing settings, well over 15 minutes.
They weren't able to remotely upload firmware this last time for some reason. I had to do it with a USB. But yes, I'm aware I need to reboot.
I don't have a generator connected yet, but will have a selector switch when everything with the inverter is resolved. Yes, absolutely certain. The only inputs to the inverter are the AC from the main panel breaker, 4 solar strings, the battery, and the smart meter (powered by the same breaker as the inverter), One thing I noted is that during an "outage" the smart meter is still powered since it is getting power from that weird 240v on the grid terminals. So I tried disconnecting the smart meter during my simulated outage, but no change.
Something is certainly wrong, but I'm not giving up.
Good to know about the grid terminals. Yes, that pre-wired terminal is there on mine as well. Anyway, I wish it were that easy. I am measuring the voltages at L1 and L2 and also the two "backup" terminals.
MajicDiver
Solar Enthusiast
This could be an indicator of a problem- I suggest you sketch the smart meter power circuit and upload. My smart meter is on a completely separate circuit and its own breaker in the main panel.
Yes, it is an indicator of a problem with the inverter that it is outputting on the grid terminals. Anyway, I will do that but have to run out now. In the meantime, here are some other things and questions:
Sometimes the LED's on the smart meter are all green, sometimes L2 is red, sometimes both L1 and L2 red. I don't think the run LED was ever red. Also, if I enable off grid function, the meter run blinks orange.
What is dry contact? Mine is off. Should it be on?
Some options I can only seem to find on the shine phone app, but not shine tools app. Is that the way it is, or just that I haven't found the right page? Also, I've been making all these changes through the app. They seem to stick, but would using a computer better?
The countdown to grid connection takes a long time, is it possible to change? It is a pain having to wait so long when making setting changes. Is there a setting for when the PV starts connecting? Mine seems to take 5 minutes or more.
Finally, I am getting battery wiring error messages again from the inverter. I thought I had that problem solved. I had contacted LG and they approved a return, but I was thinking I wouldn't have to return it, but now, I'm going to do it since all these issues may be a problem within the battery.
Battery