Power-One solar Inverter driving me NUTS!!!

[truclacicr]

Re: Power-One solar Inverter driving me NUTS!!!

That Meder device appears to be a 12V reed relay.

https://cdn.badcaps-static.com/pdfs/...147bd57807.pdf

[truclacicr]

Re: Power-One solar Inverter driving me NUTS!!!

Look at page 4 of this document:

https://cdn.badcaps-static.com/pdfs/...95a1307f0b.pdf

Notice that the positive and negative PV conductors pass through a detection device that senses the net current and produces a GFCI interrupt to the controller if the sensed net current is non-zero. That's the way that an RCD / ELCB works.

[CapLeaker]

Re: Power-One solar Inverter driving me NUTS!!!

I think we are on the right track. Now its to figure out on what board the problem is. Then go from there.
Leakage could be on FET's, diodes, IGBT's, some burnt crap somewhere, a chaffed wire etc.

[mitsu2k]

Re: Power-One solar Inverter driving me NUTS!!!

I went over these pictures again and maybe I found something or not. LOL
If you look at that spot I marked, it looks like a dark area (like a light burn mark) compared to the others.

Take your DMM in diode mode and check the 3 legs of all the IGBTs and diodes on this board. See if they are shorted or leaky.
How to IGBT? Here: https://www.incbtech.com/circuit-ben...s-ins045e.html

I also need to mention that this area circled showed signs of heat as well. All that rubber silicone coating stuff was really really brown in this area and especially underneath that blue relay. I cleaned it up and checked all the components in that area such as diode, there was a couple vets, a PNP, and NPN, and some resistors as well as the relay itself although they showed significant signs of heat, they all tested just fine. I actually remove them and tested them so it's to avoid any misreadings from in circuit testing. Not sure why this area was getting hot. I wish I would have taken a photo before hand, but I got ahead of myself and cleaned it up.
I found a phot with that blue relay removed and photo taken during the cleanup process.

[mitsu2k]

Re: Power-One solar Inverter driving me NUTS!!!

PVI-3.0 3.6 4.2-OUTD-US Manual

https://powertripenergy.com/wp-conte...4.2-manual.pdf
https://ressupply.com/documents/abb/...-US_Manual.pdf

CASR series Current transducer

https://www.lem.com/sites/default/fi...asr_series.pdf

LEM's product range

https://www.lem.com/en/product-list?keys=



As I see it, we should be looking for a fault on the PV side.

I believe that GRP is Photovoltaic GRound.

The CASR/25/SP3 transformers are measuring the current in one leg of each PV circuit. Ground fault detection requires that the differential current be sensed, ie we must sense the current in both legs. Therefore we must look for a detector on the PCB that has the bulk capacitors. This detector must be connected to BOOST1, BOOST2 and GRP.

The CT...SP4 transformer appears to be sensing the AC current, so I don't think we should be looking here.

Thank you, so I can understand, would we be looking for a leaky cap or a bad CASR/25/SP3? When you say "Bulk Capacitors" do you have an idea of which ones those might be? I can take more and better photos if need be.
These caps in the photo are connected to both boosts and GRP. I have never removed these caps but I did check them and they did read the 30 uF as expected. However, they could certainly be leaky. They did test OK with my ESR meter but I know that is not a proper test for leakage.

[mitsu2k]

Re: Power-One solar Inverter driving me NUTS!!!

I went over these pictures again and maybe I found something or not. LOL
If you look at that spot I marked, it looks like a dark area (like a light burn mark) compared to the others.

Take your DMM in diode mode and check the 3 legs of all the IGBTs and diodes on this board. See if they are shorted or leaky.
How to IGBT? Here: https://www.incbtech.com/circuit-ben...s-ins045e.html

Great, I will do that as soon as I get home. Thank you.

[truclacicr]

Re: Power-One solar Inverter driving me NUTS!!!

PVI-3.0 3.6 4.2-OUTD-US Manual

https://powertripenergy.com/wp-conte...4.2-manual.pdf
https://ressupply.com/documents/abb/...-US_Manual.pdf

CASR series Current transducer

https://www.lem.com/sites/default/fi...asr_series.pdf

LEM's product range

https://www.lem.com/en/product-list?keys=

The red 'GFI' (ground fault) LED indicates that AURORA Inverter is detecting a ground fault in the DC side of the photovoltaic system. When this kind of fault is detected, the AURORA Inverter disconnects from the grid and the corresponding fault indication appears on the LCD display. AURORA Inverter remains in this condition until the operator presses the ESC key to re-start the grid connection sequence. If pressing the ESC key doesn’t clear the ground fault check the ground-fault, fuse located in the switchbox. If AURORA Inverter does not reconnect to the grid, contact Power-One Technical Service.

As I see it, we should be looking for a fault on the PV side.

I believe that GRP is Photovoltaic GRound.

The CASR/25/SP3 transformers are measuring the current in one leg of each PV circuit. Ground fault detection requires that the differential current be sensed, ie we must sense the current in both legs. Therefore we must look for a detector on the PCB that has the bulk capacitors. This detector must be connected to BOOST1, BOOST2 and GRP.

The CT...SP4 transformer appears to be sensing the AC current, so I don't think we should be looking here.

[CapLeaker]

Re: Power-One solar Inverter driving me NUTS!!!

I went over these pictures again and maybe I found something or not. LOL
If you look at that spot I marked, it looks like a dark area (like a light burn mark) compared to the others.

Take your DMM in diode mode and check the 3 legs of all the IGBTs and diodes on this board. See if they are shorted or leaky.
How to IGBT? Here: https://www.incbtech.com/circuit-ben...s-ins045e.html

[mitsu2k]

Re: Power-One solar Inverter driving me NUTS!!!

put the boards back into the chassis with all the wires disconnected in between them. Make sure you use all the screws on the boards!!! Then probe the DC Inputs labelled side (4 connectors) against earth ground and note things down. then go to the other end of the board where the wires with connectors plug in and test there. That would be the other side of the relays.

Go for the low hanging logical fruit first. Don't go too test crazy with the megger, because you can damage circuits that aren't meant to run 250v. Stick with testing the DC power inputs only.

You got it buddy. I will report back tomorrow. Thank you!!

[CapLeaker]

Re: Power-One solar Inverter driving me NUTS!!!

put the boards back into the chassis with all the wires disconnected in between them. Make sure you use all the screws on the boards!!! Then probe the DC Inputs labelled side (4 connectors) against earth ground and note things down. then go to the other end of the board where the wires with connectors plug in and test there. That would be the other side of the relays.

Go for the low hanging logical fruit first. Don't go too test crazy with the megger, because you can damage circuits that aren't meant to run 250v. Stick with testing the DC power inputs only.

[mitsu2k]

Re: Power-One solar Inverter driving me NUTS!!!

Be careful what you test. You can't use the megger like that on low voltage things. So just stay at the high voltage DC power rails for now.
Put that inverter back in the box and just test around on the high voltage DC rails (there are 2) with the cables disconnected between the boards. We don't know if the problem is on the first board with the bad relays, or the other board with the transformers and the caps.

Ok good idea isolating the boards. Just so I am clear, when you say "rails" can you please circle them on my photo? I am assuming you are referring to the DC inputs but I want to be sure.

[CapLeaker]

Re: Power-One solar Inverter driving me NUTS!!!

Great info there. The string voltage is 250v. The inverter specs state that input voltage can be up to 600v dc. However I know I get the error at 100v so I will start at 100v and work my way up. The megger I will be using has I believe 125, 250, 500, 1000v settings. I think I will probably stay at 250 max because many of the caps are only rated for 305v. The biggest issue is going to be testing on either side of the relays. The issue being that there are many "GP" ground pole screws. 12 to be exact. This is where the board gets its ground. Only problem is, all those ground poles have no continuity to each other unless they are screwed to the bottom plate. I will attach photo. So I will have to come up with something creative to get around this.

Be careful what you test. You can't use the megger like that on low voltage things. So just stay at the high voltage DC power rails for now.
Put that inverter back together in the box and just test around on the high voltage DC rails (there are 2) with the cables disconnected between the boards. We don't know if the problem is on the first board with the bad relays, or the other board with the transformers and the caps.

[CapLeaker]

Re: Power-One solar Inverter driving me NUTS!!!

It's true, a Megger test for like 5 seconds is worth nothing unless it comes up with a basically short straight away. Gotta be at least one minute to test and if your MOhms value rises during that time, that's good and the end value at the one minute mark is used.

Yeah, go straight for the 250V rating on the Megger for this inverter high voltage rails. Don't even think on pussyfooting with a 100V or 50V.

I think you got too much voltage on the DC input from the panels to the inverter. You should have taken one or 2 panels off. On a cloudy day with sun peaking through a lot, you will be surprised how much peak power you get out of your panels. I've got 9.5kw worth on panels and I've seen over 11kw on these days.
10kw worth on panels on a 10kw inverter isn't a good idea. You'd be begging for trouble.

I've got a Fluke 1587, it tops out at 1000V. I don't use it often, but it surely comes in very handy for troubleshooting odd shit, like wiring, GFI, motors, generators, heat pumps, deep well pumps etc.

[sam_sam_sam]

Re: Power-One solar Inverter driving me NUTS!!!

First off, a Megger test is done over time

This was an interesting explanation of how to use a megger on an inverter

The highest voltage megger I have used is the 500 volts version before which has the difference color LED lights tell you what megohm range you are in

[mitsu2k]

Re: Power-One solar Inverter driving me NUTS!!!

First off, a Megger test is done over time. So pressing the button for 5 seconds doesn't count unless its a short.
What is your string voltage of the solar panels? Since your inverter is going into ground fault with like minimum turn on voltage, I suspect you should read almost a short.
Usually 6 figures reading like 100 -1000 or better MOhms is good. once you get low readings like 1Meg that's no good. Some Meggers actually will tell you the voltage it can put out. So you want the max voltage rating it can put out for the selected voltage setting.
Example: Megger set at 250v, open leads: You get something like 261V 275MOhm. Great!
set at 250V and you get 1 MOhm.... well thats garbage.
Ideal would be the OL or the highest reading the megger can do.
What to expect? Hopefully that highest MOhm reading for the rated input voltage rating of the inverter. MOV's etc should test practically like OL. MOV not reading like OL, its garbage in my book.

Great info there. The string voltage is 250v. The inverter specs state that input voltage can be up to 600v dc. However I know I get the error at 100v so I will start at 100v and work my way up. The megger I will be using has I believe 125, 250, 500, 1000v settings. I think I will probably stay at 250 max because many of the caps are only rated for 305v. The biggest issue is going to be testing on either side of the relays. The issue being that there are many "GP" ground pole screws. 12 to be exact. This is where the board gets its ground. Only problem is, all those ground poles have no continuity to each other unless they are screwed to the bottom plate. I will attach photo. So I will have to come up with something creative to get around this.

[CapLeaker]

Re: Power-One solar Inverter driving me NUTS!!!

First off, a Megger test is done over time. So pressing the button for 5 seconds doesn't count unless its a short.
What is your string voltage of the solar panels? Since your inverter is going into ground fault with like minimum turn on voltage, I suspect you should read almost a short.
Usually 6 figures reading like 100 -1000 or better MOhms is good. once you get low readings like 1Meg that's no good. Some Meggers actually will tell you the voltage it can put out. So you want the max voltage rating it can put out for the selected voltage setting.
Example: Megger set at 250v, open leads: You get something like 261V 275MOhm. Great!
set at 250V and you get 1 MOhm.... well thats garbage.
Ideal would be the OL or the highest reading the megger can do.
What to expect? Hopefully that highest MOhm reading for the rated input voltage rating of the inverter. MOV's etc should test practically like OL. MOV not reading like OL, its garbage in my book.

[mitsu2k]

Re: Power-One solar Inverter driving me NUTS!!!

I think this inverter is advertised for 3.6kw. This being said, I think it's only good for 2.5kw tops.

Let's see what happens when you get that Megger. Then go for the high voltage positive and negative DC to earth ground before and after the relays.

What kind of readings should I be looking for with the megger? Meaning approximately how many megaOhms would you think should be normal? I do understand the higher the better.

[mitsu2k]

Re: Power-One solar Inverter driving me NUTS!!!

Great idea! I did suspect that the relays not being clicked on would not give me accurate readings but your idea solves that problem.

[CapLeaker]

Re: Power-One solar Inverter driving me NUTS!!!

I think this inverter is advertised for 3.6kw. This being said, I think it’s only good for 2.5kw tops.

Let’s see what happens when you get that Megger. Then go for the high voltage positive and negative DC to earth ground before and after the relays.

[mitsu2k]

Re: Power-One solar Inverter driving me NUTS!!!

relay joints shouldnt burn unless the relay pins are getting hot - are the relays burning inside?

There are 4 relays that have exhibited this issue. This occurrence of the contacts burning out has happened to me about 4 times. Each in a different relay. Usually one relay at a time. It is a common issue with this inverter. If you Google “Aurora inverter E031 error” you will find several youtube videos on it. The first 3 times it happened the relays were still ok. The last time it happened one relay actually burned up and stopped functioning. I have a photo of it above in post #23

Under normal operation of this inverter, the relays can be heard cycling every couple seconds or so but obviously not now with the GFI error.

The GFI error may or may not be as some kind of side effect of the last relay burnout. I cannot be sure. However usually when the relays burn out, I get an E031 error but this last time, there was no E031 error. I only found the inverter with the GFI light lit and no error code. Very puzzling.