Trace SW5548 Problem - Which Board/What Controls the Inverting?

Re: Trace SW5548 Problem - Which Board/What Controls the Inverting?

Hi boB,
Thanks for the reply. Yes, this is one of the inverters from the SMUD project (mfg in 96') and because it's a bit unique I would really love to get this online especially because of my set up. The PV array does connect directly to the battery input and yes, there is a large capacitor on the input. So it is basically a 48VDC in, 240VAC (split phase) out, batteryless grid-tie inverter which is hard to come by. And I don't need to stack two to get the 240VAC to feed into the house/grid. The only other inverters I can find to replace this thing are those Chinese made extruded aluminum ones that will likely only output half of their rated power efficiently. Even the hydrid ones which take 48VDC in (outback, Xantrex XW) require at least 100AH battery capacity to function properly.

So I got the power MOSFET board to the point where it keeps the magical smoke in and like I said before, everything powers up and seems to work fine except it does not start the inversion process. I did not understand what you meant by:

"What I forgot was if it could operate as a regular inverter but you said it did before it broke so I guess so."

but this IS grid tie only and the way it is suppose to operate (which I imagine is simialar to a regular SW unit) is that is powers up on DC input and immediatly it will start to generate the sine wave and will search for AC1 in. If it gets a good AC input, the green light comes one for AC1 good and it will begin the sync process. I see the AC1 voltage cycle up and down as it will tries to get a lock and once it does, the large output relay engages and connects the inverters sine wave withe grid and starts feeding back into the grid. The issue I have is when I power on DC input, the inversion process does not even start (no humming). If I scroll through the "meters" menu, it is verified that there is no AC Volt output from the inverter as it displays 6 to 10V which is likely just random noise on the display. I can connect the AC1 input and it will get a lock and will sync, but because there is no AC Volt out, the relay never engages. So that's where I'm at, trying to figure out what tells the drivers for the MOSFETs to start working. Is this inversion process controlled via one of the replaceable fast pic chip on the control board? Is this even controlled by the control board or is it done on the MOSFET board? Could the MOSFETs that fried have taken out the drivers on the MOSFET board or does this sound more like a waveform control issue?

Are the 48V SW control board unique, or is it just the 5 swappable ICs unique? The control board looks like it only gets low voltage through the ribbon cables, does the MOSFET board step the DC voltage down to 12V, thus all of the control boards are the same other than the 5 ICs? The extra board I have is from a 2512 (so 12v version), however the part number on the board is the same and looked almost identical so I swapped out the 5 ICs and like I mentioned previously, it acted exactly the same so that board seemed to work which makes me wonder if the original board is also fine and whether one of the ICs may be bad and just not initiating the inverting process. This at least suggests to me that the control board are the same. The only difference I noticed is that instead of showing 52VDC in on the display, it showed like 76VDC which I'm guessing is due to a slight difference of the boards...but the fact is powered up and did the same thing as the original board leads me to believe the actual original board is fine, but maybe one of the ICs is bad.

Attachment not found.
Can you identify which of the ICs on the board may be compatible from board to board (i.e. if I used the chip from the 2512 board) to see if maybe the chips are bad? The stickers had come off of all but two of the chips. If I was to identify the chips from left to right, the lower left chip that still has a sticker would be #2, as #1 would be 3 chips to the left of #2 and is missing it's sticker. #3 is in the center of the picture and has a sticker, #4 is just to the right of #3, and #5 towards the right hand side has remnants of a sticker still, but no numbers. If I could figure out whether any of the ICs from the 2512 board are compatible with the 5548, then I could try those chips in it's place. My guess is that I would have to at least keep the chip that has the main program difference with the UPV version otherwise potentially more smoke. Anyone have a control board from an SW5548 or have any chips from an SW5548 control board? Maybe I am barking up the wrong tree, please let me know...maybe it is not the control board or the chips at all?

I have to hand it to you, you have a great memory considering the details you are providing. Please keep posting, it is the only way us newbies will gain this information in hopes of keeping these things alive. As Cariboocoot said, replacing it is likely the most logical choice (which may happen), but I would really like to get this going considering my options and it would be nice if I can revive an 18 year old beast.
Thanks for the information. If you can think of anything else or if anyone else reading this has suggestions, please post!