Hi Doc Hubert!
Yeah i thought about the 120 vs 240 version difference. It shouldnt matter unless they were monitoring the 220v to the maintx terminals. Quick verification, put all leads back where they were b4 you started and turn pj on. Verify output voltage is correct. Then place ac voltmeter on maintx terminals and measure. If this voltage on board terminals measures 220 then you need to keep that voltage (near 220). You may or may not need a different transformer. I suspect the original design brings in 220v to the board, if so, switch the windings around.
1.Start by leaving everything connected as original verify normal operation then power off.
2. jumper connect 120v winding to the 120v leads that go to a 120v outlet or cut cord off a discarded appliance and drive the 120(low volt wdg of your xfmr) then jumper(connect) only one of the 220(high voltt) wdg to maintx-N. Leave the 2nd lead disconnected from anything.
3 now power it up. Measure with ac voltmeter between both of the 220v xfmr leads, hopefully it will read 210v. Now measure between the unconnected lead of your new xfmr and maintx-L this voltage should be less than 10v AC, if it measures like 210 or 250 then power off and swap the two leads of your new transformer. Now power up again and verify only a small volt difference. Ideally if your voltage was 224 between maintx N-L, you will want maybe 208. That will cause feedback to increase output to target 224 again and add 16v to the highv winding 224+16=240v which will bring 110 output to 120v,
After verifying this, then shut power off and rewire the 120v side of your new xfmr to a permanent location near pj transformer, not outlets because if fuse blows you would loose feedback. Then connect the 240 or should i say 208 side of your xfmr to maintx-N and maintx-L. Of course remove all terminals that were on each and bolt wires together creating two separate maintx terminals that do not touch the board. you can float 1 or both of them its up to you, i mainly just did one because i only had 1 bolt small enough to go through those rings and it makes it neater to leave maintxN original. Im not sure theres any benefit in floating the second lead.
Sounds like u will be fine though, you almost had it. Im wondering thougb didnt u say you had an original turns ratio of 120 to 208? I think that would hav been perfect unmodified. Better test and see first, maybe its perfect right now. I'm thinking you dont want higher than 120/240 output as you will drive up idle current and reduce headroom for battery voltage sag. Then you will have to alter turns ratio of the toroids. I'm with you though the 109-112v was just too low. I had trouble with that when i had it out at the solar panel and ran 100' wire to the load center in basement then by the time it got to the garage where freezer is
. I have since with oztules advice acquired an awesome 3.5kwgrid inverter that can do 400v mppt and put in basement so i dont loose with long cable run. Next to load center the 112v wasnt a problem and wouldnt have increased mine but i couldnt adjust parameters of my grid tie and wanted to run voltage centered between 120v parameter which was 107-130 (dont know why UL1741 makes em monitor the 120 when its supposed to feed on L1-L2
Back to your situation, I think you just about have it whipped, the power meter i mentioned is the one on the pj faceplate, it does this by the phase angle of power factor and the current transformer, somehow I inverted it?
Maybe i switched the toroidal transformer leads and its reading a negative power factor instead of positive one?
i will figure it out, thats why i wanted you to be sure to keep polarity of lead wires original.
Regarding the power control, i havent corrected mine but did have a look at the board and the metal current transformer. Looks like i could desolder current transformer from board and mount it on a new board which would allow isolation while leaving secondary side connected to control board. This should restore normal power control including fans. I was wondering why my fans.
never came on anymore. Kind of missed it. I ender up doing my own cooling thing like everybody else. I couldnt complain about fan control on this one, before i bypassed current control it used to come on low speed then faster and a high speed when it went over 2kw. I have no toroids in the box anymore and the fet sinks barely get warm to touch running 1.5-2k all day