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.
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.
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