Yes you are probably correct. I will try and test all components in that area to the best of my ability. So far I did not see anything that was shorted. That silicone type coating all over the board makes it difficult.
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the lamp circuit will be fine i guess . what i am trying to see is what turns it on and then see what tells it to come on . there must be something that measures the resistance to earth ground from panel outputs and i suspect something there is amiss . datasheet for the mcu might help a bit .Comment
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Not sure which one is the MCU for this circuit. I do know the alarm relay is on this corner of the board. Do you think this might be the MCU? Sorry for the upside down pic. it’s the only way I can get it under my microscope.
edit: looks like that one is a USB to serialLast edited by mitsu2k; 11-23-2023, 02:30 PM.Comment
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TUSB34101 USB
to Serial Port ControllerComment
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The strange part is that the GFI LED comes on instantly before the unit has time to go through its checks. I have seen videos online where the LED did not come on until after the checks.Comment
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from what i can make out its behaving correctly its only the "A" models that dont halt at this fault . unless yours is an "A" modelComment
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Not sure what the “A” model is but here is the labelsAttached Filesif you find these attachements useful please consider making a small donation to the site
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OK now I’m thinking there is really a ground fault. When I connected it back up to the array and turned it on, I tried to measure current from positive, DC, negative DC, to earth ground. I was not able to measure any current, but when on the positive and touching the earth ground with my probe, I noticed very slight arching. I don’t get this arcing on the negative side.
I don’t think that should be the case. When I measured for voltage between the positive terminal and earth ground, I get approximately 149 V. Between the negative and earth ground I get approximately 87 V. The array itself positive to negative measures approximately 256 V. When I disconnect the array from the inverter and just measure the positive and negative coming from the array to earth ground I get very low transient voltage, like 5 to 10 V.
but the question is, where could this leakage be?
edit: when I remove the 4 red MOVs and perform the above test again, I get practically no voltage from negative to earth ground but the voltage from positive to earth ground jumps up to about 191vLast edited by mitsu2k; 11-24-2023, 03:25 PM.Comment
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leakage is on the negative if indeed there is any leakage .. the measurements suggest there is . maybe a cable is damaged or got water inside it .Comment
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Are you referring to the cables coming from the array? I tested those disconnected from the inverter and they seem to test fine. I tested them with a mega and the resistance was in the high mega ohms on both the positive and the negative to earth ground. The inverter itself measures them above 20 mega Ohms when it performs it start up test.
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That sounds like a real ground fault all right. I would start again bare ass from square one. This time take as sheet of paper and make nots want you did, how you did it and what the result was.
i do have a document that comes with a different inverter that deals with this on the solar side.Comment
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I have a question about the MOVs. None of them look discolored or show any signs of heat. They test open with DMM. I know this is not a proper test but should I just not worry about these?Comment
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These are 3 legged MOVs. The middle leg on the positive terminals seems to be connected directly to earth ground.Attached Filesif you find these attachements useful please consider making a small donation to the site
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The third leg is a thermal fuse.Comment
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2 is the middle leg. Number 3 is the closest leg to 2. Number 1 is the furthest away from leg 2 (middle pin).
leg 2 to leg 3 is the thermal fuse and should read a dead short.
leg 1 to leg 3 is the MOV and it should be either OL or full scale resistance on the Megger.Attached Filesif you find these attachements useful please consider making a small donation to the site
Last edited by CapLeaker; 11-24-2023, 09:29 PM.Comment
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I tested between the first and third legs in my photo. Here are the results.
500vdc test
#1
175 mOhms
#2
205 mOhms
#3
215 mOhms
#4
239 mOhms
I also tested the two blue ones on the AC side and those tested over 4000 mOhms. (full scale on megger)
Not sure what these results mean. Could all 4 of them be bad?Last edited by mitsu2k; 11-24-2023, 09:43 PM.Comment
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Hello,
I need help to find the value of 2 missing capacitors ( C102 and C117) on my Easun SMH-II mainboard (solar hybrid inverter). I circled it in red on the close-up picture. The 2 old capacitors are completely missing, so I have no reference. Does anyone have this board and can tell me the value or make an educated guess based on the location ?
My model is : EASUN SMH-II 7 KW
Mother Board : P/N 18947-002401250250
Maybe the EASUN SMH-II 4.2 KW have the same capacitors
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My parent's solar inverter died after 5 years of good service.
It's a called hybrid inverter:
- It can go with or without batteries
- It has 2 MPPT (8 330W panels in 2 strings) -> 5280Wp
- A 20kWh lithium battery previously used in a Nissan leaf (14S at 4.1V max) -> 57.4V
Panel is showing error 17 and the battery connection has disappeared. On the other hand, is delivering load, MPPTs are working and it's exporting energy to the GRID. Not that "bad".
Let's open it......
I see that 150A fuse is gone and the... -
I just seen this item is this a good idea if why and if not why not
Here is the website link to it
https://www.ebay.com/itm/40599879518....c101465.m3507 -
My cheap crappy 1KW grid tie inverter (GTI) seems to keep blowing IGBTs. When I first got it, it had two failed IGBTs. It used four 60N100's (TO264). I bought 5 from a dubious source (fleabay) and replaced just the two that were dead. The GTI worked for almost two years but recently one of the two that I replaced failed. Since I had three spares, I replaced the dead one. Then a few weeks later it failed again. Weird. Well since I bought dubious China-sourced IGBTs from fleabay it could very well just be a mixture of fakes. I replaced it, but then a day later it failed again! I put in the last...
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I just got this tv today and it appeared to have no backlight on. After taking off the rear cover and checking again in the dark I can see that MAYBE one quadrant is lit.. But still it's quite dim. I was going to check the LEDs with my tester, and I found LED 1 and LED 2 + pins on the wire from the inverter, but I couldn't identify a ground. Nonetheless I tried using a mounting screw on the inverter board and also the chassis as ground but regardless my tester reads 300 which is what it reads when there is no voltage draw.
I don't know how exactly to test the inverter itself. Is it...
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