Power-One solar Inverter driving me NUTS!!!

[CapLeaker]

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

Aaargh shiiiiiiiiiiiiiieeet! Sorry, I lost my long post. So I got to write again and this one is shorter.

The test you did on the first board negative to earth GND ringing it at 24MOhm is good, that is what I would expect.
The test with positive to earth GND at 3.2 looks kind of suspicious, but at the same time it could be normal for this thing.
The 1MOhm tests on the other board, I am not buying that this is any good.

As more voltage you got, the more MOhm or isolation you need! My solar inverter has three strings at 800V, 800V and 700V DC. IF my isolation in the inverter would be only 1MOhm, my house would be burnt to the ground. Period.

I also think that the numbered GRP screw holes are GRound Points. However I don't think they are connected together if the board is out and you measure from one numbered GRP hole to another one on the opposite side of the board. What I am getting at is that the ground is only fully working, if all screws are used to mount the board to the chassis AND providing that they make proper connection between the PCB and the chassis too! Otherwise you end up with one GRP pin floating which makes the unit not work either.

I am suggesting following tests board installed and out of the chassis:
-> With the first board out of the chassis check the numbered GRP screw holes against a different one throughout the board. Probably most are open.
-> Measure the same thing installed in the board and you should have continuity on all GRP points.
->With the first board installed (but no wires connected) check the continuity between earth ground and the GRP plug on the back where the wire plugs in.
then go earth or GRP plug one by one over to the Boost1, Boost2, Bulk etc.

Once you figured out the grounding or GRP point situation, install the second board (with the big caps)into the chassis and don't hook any of the wires up.
-> earth ground to GRP plug on the second board. If they are connected, do:
-> earth or GRP plug to Boost1, then over to Boost 2, Bulk etc. one by one.

I know this is painful, but lets see what this does. Over all I say the problem is on the second board with the big capacitors ringing it at 1MOhm. That can't be right.

[mitsu2k]

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

Dies anyone know what GRP means? Is it something like Ground Return Path or Pole? Just wondering if this is the case then it may be some kind of loop connection which might render my narrowing the issue it to the second board invalid.

[CapLeaker]

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

I think in the chassis they are all connected. Out of the chassis they are not. Its just a GRound Point to me.

[CapLeaker]

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

Can we have a picture of the second board the bottom? Haven't seen that yet. Thx.

BTW, I wanna figure out what the deal is between the GRP plug and the GND, there shouldn't be continuity there. Something is a miss somewhere that involves the GRP plug, the HVDC positive and negative and earth gnd.

Some numbered GP screw holes don't look good in the pictures.

[mitsu2k]

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

I am such an idiot. I put the second board back in without taking pics of the bottom. I will remove it again and get those pics uploaded. Sorry for my oversight. I am getting worn out.

[mitsu2k]

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

I took several pictures at different angles of the bottom of that second board.
By the way, I read your post about losing everything you had written. I know how frustrating that is. I just want to thank you again for taking the time out to rewrite it.

[mitsu2k]

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

I am suggesting following tests board installed and out of the chassis:
-> With the first board out of the chassis check the numbered GRP screw holes against a different one throughout the board. Probably most are open.
-> Measure the same thing installed in the board and you should have continuity on all GRP points.
->With the first board installed (but no wires connected) check the continuity between earth ground and the GRP plug on the back where the wire plugs in.
then go earth or GRP plug one by one over to the Boost1, Boost2, Bulk etc.

Once you figured out the grounding or GRP point situation, install the second board (with the big caps)into the chassis and don't hook any of the wires up.
-> earth ground to GRP plug on the second board. If they are connected, do:
-> earth or GRP plug to Boost1, then over to Boost 2, Bulk etc. one by one.

I know this is painful, but lets see what this does. Over all I say the problem is on the second board with the big capacitors ringing it at 1MOhm. That can't be right.

You are correct in that all of those grounding screws must be installed into the chassis for the ground to be continuous throughout. I did check for continuity between earth ground and all of the plugs that go to the second board and I found no continuity. Which is puzzling me because I don’t see any other ground points on that second board. Unless the screw in the center of the second board labeled “GP3“ is connected to ground through a center layer of the board.

I have both boards out right now. I will leave them out for a while, while I take a break to get my head straight and in case you need better photos or testing.. Then I will proceed with the tests you outlined above.

[mitsu2k]

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

on another thought, I wonder if that main board is also a 3 or 4 layer PCB. If so, I may have a problem with connection on the pins that the relay burned out.



Edit: that main board does not appear to have any layers within. Just top and bottom that I can tell.

[sam_sam_sam]

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

Is there any part numbers on the IGBT module if there is can you please post it thanks

Because depending on the model number sometimes there is a test procedure for that particular one

[CapLeaker]

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

The first board all I can see is a double layer board. The second board is at least 3 layers. No problem for writing that post again. It’s very interesting how this inverter works. MPPT is complicated, but more efficient. Anyway… would be too nice to find a service manual with schematics for this thing.

[mitsu2k]

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

Is there any part numbers on the IGT module if there is can you please post it thanks

Because depending on the model number sometimes there is a test procedure for that particular one

I'm sorry, what is the IGT module? I can take a pic

[mitsu2k]

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

The first board all I can see is a double layer board. The second board is at least 3 layers. No problem for writing that post again. It's very interesting how this inverter works. MPPT is complicated, but more efficient. Anyway… would be too nice to find a service manual with schematics for this thing.

Schematics would be great but I have not been able to find any and the company has sold several times. And yes you are correct. This is one complicated sucker

[sam_sam_sam]

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

I have this happened to in the past working on a board that several relays had bad pin connections and it was a multi layer board the top layer was not getting any solder on the top layer but only the bottom layer because the trace in between was not there anymore and it drove me nuts to figure out why this board was not working properly

I would highly recommend removing all the relays and very closely look at solder traces between the top layer and the bottom layer and see if it looks like there should be one or not

I not suggesting that are but some time when the bottom traces are gone and there is a top trace the solder does not travel to the top trust me I have happened to me several times in the past

[sam_sam_sam]

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

I’m sorry, what is the IGT module? I can take a pic

Most of the time they are module that many pins on it but the only way to be sure that it is a IGBT module is to google it

I forgot the “B” sorry about that

[mitsu2k]

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

Most of the time they are module that many pins on it but the only way to be sure that it is a IGBT module is to google it

I forgot the “B” sorry about that

There are two of these on the board with the 4 large capacitors.
https://cdn.badcaps-static.com/pdfs/...f9e4568a9c.pdf

Also these 7 guys circled in the other pic have no part number on top

[mitsu2k]

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

I removed a bunch of those caps connected to ground and tested them with the megger. Not sure if that is a proper test but they all showed over 4000 megaOhms. Except for the two large white ones (30uF) on the main board. Those initially came back over 4000 megaOhms but after about 7-8 seconds they started dropping. I did not wait to see how far they dropped but they were dropping pretty steadily.

[mitsu2k]

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

On the second board, I installed it without plugging in any of the wires. I checked for continuity between earth ground and all of the wire terminals on the board. Found no continuity to ground to any of the terminals.

[mitsu2k]

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

I have this happened to in the past working on a board that several relays had bad pin connections and it was a multi layer board the top layer was not getting any solder on the top layer but only the bottom layer because the trace in between was not there anymore and it drove me nuts to figure out why this board was not working properly

I would highly recommend removing all the relays and very closely look at solder traces between the top layer and the bottom layer and see if it looks like there should be one or not

I not suggesting that are but some time when the bottom traces are gone and there is a top trace the solder does not travel to the top trust me I have happened to me several times in the past

I know for sure that some of the contact pads on some of those relays are completely separated between the top and bottom pads due to the burning out. But as far as I can tell, the bottom and top are carbon copies of eachother so just the bottom connected should be sufficient. However, I got nothing to lose. I will remove all the relays and check again. It is possible I'm missing something.

[CapLeaker]

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

Out of curiosity: The two 60V PSU's you are using to start the inverter, they aren't earth grounded on the negative? Just saying if you use one or two linear power supplies that have an earth pin on the power mains plug, the negative coming out of the PSU is coupled to earth ground.
Keep this in mind, that you may need a isolation transformer on these power supplies.

[sam_sam_sam]

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

But as far as I can tell, the bottom and top are carbon copies of eachother so just the bottom connected should be sufficient. However, I got nothing to lose. I will remove all the relays and check again. It is possible I'm missing something.

You need to take a meter and check each relay trace that has a connection on the top and bottom on that pin and make sure that you have connection between the two of them if not there would probably be an issue if there is not a lot of current on that pin you can take a strand of wire and put it in the pin hole and solder it to the trace on the top to the bottom trace now if you have a lot of current on the relay pins this is going to be more difficult to do ( unless the traces are some what big enough to enlarge the pin holes and put several strand’s around the pin hole to be able to handle more current )

One solution might be is to put the relay on a separate board and keep the hook up wires as short as possible I personally have not had to do this before so I am sure what kind-a of success rate you would have doing it this way would be

Please take a picture of top and bottom of the board with out the relays in place and I might be able to give you some suggestions for a solution to your problem