Felix Posted November 16, 2021 Share Posted November 16, 2021 Hello everyone, I'm running my Powerjack 8KW LF inverter for almost 6 years now without any big problem. This said, I got new appliances who are sensitive to the frequency that my inverter generates (50hz at the moment). Anyone here found and adjustment screw on the main board to tweak the generated frequency from 50hz to 60hz? Unfortunately, I do not have the model revision number. Here are pictures of my actual model: Hope someone can give me a hand on this. Thanks!! Felix Quote Link to comment Share on other sites More sharing options...
Sid Genetry Solar Posted November 16, 2021 Share Posted November 16, 2021 Looks like you got an oldie there--and the old ones just seem to keep running. Frequency is determined by the "CPU" (it's an MCU, but I digress!) Control boards with the Microchip CPU have frequency adjust with a button (switching between the 2). I can't tell for sure, but I'm guessing on that inverter, you'll need @dochubert to chime in. What's the control board version on that inverter? Quote Link to comment Share on other sites More sharing options...
Felix Posted November 16, 2021 Author Share Posted November 16, 2021 Thank you for this nice answer. Much appreciated. Where exactly can I find the board revision number? On the board itself? Quote Link to comment Share on other sites More sharing options...
Sid Genetry Solar Posted November 16, 2021 Share Posted November 16, 2021 Yes, it should be printed on the board somewhere. "LF BOARD REV[xxx]" Quote Link to comment Share on other sites More sharing options...
dochubert Posted November 16, 2021 Share Posted November 16, 2021 Hi Felix, You're control board revision number will be right next to the black relay that has a 'DC 12v' sticker on it. Looks like a v3.4 to me (guessing). Sorry but there is no adjustment to change frequency on the older control boards like yours. Quote Link to comment Share on other sites More sharing options...
Sid Genetry Solar Posted November 17, 2021 Share Posted November 17, 2021 If it uses the Microchip PIC main processor, I am relatively confident we should be able to get it to run 60Hz...though it may take tracing pins on the CPU to connectors to find the required pins for the frequency adjust button. (If it uses the older Motorola/Freescale processor, you might be out of luck though.) @FelixWhat we need to know is the control board version number and/or just a better closeup of the PCB (we can read the number right off it then / check CPU manufacturer). Once we know what version control board it is, I might even be able to ask Sean for info. Quote Link to comment Share on other sites More sharing options...
dochubert Posted November 17, 2021 Share Posted November 17, 2021 I looked through some forums' posts but found nobody had converted an older powerjack from 50hz to 60hz. That said, since powerjack made both versions, the control board should have someplace to make the choice. A solder pad or a resistor that gets removed. Looking at an old v2.2 control board I saw a solder pad labeled "Adjust" next to connector CN4 on the transformer end of the board. There is a resistor soldered to it that reads 13 ohms with my meter. Note that control board has nothing connected to it. No power, transformer, or other connections. Readings with anything connected could change the value of the reading in ohms. Caution! Take no ohm readings with ANY power source connected! Felix, if your 50hz control board has either nothing (open connection) or some value different from 13 ohms across the Adjust solder pad, we may have our selection point. Please check and let us know. Quote Link to comment Share on other sites More sharing options...
Sid Genetry Solar Posted November 18, 2021 Share Posted November 18, 2021 3 hours ago, dochubert said: Looking at an old v2.2 control board I saw a solder pad labeled "Adjust" next to connector CN4 on the transformer end of the board. There is a resistor soldered to it that reads 13 ohms with my meter. Any chance this has something to do with the battery charge current / overload protection (one and the same, heh heh)? Up until v9, they would adjust the resistors on the board; at v9+ they added a small SMT "DIP" switch to make it easier to adjust the "gain" of the current feedback circuitry. The resistor's placement next to a 2-pin connector AND an LM358 makes it look more like a current sense transformer load resistor. Quote Link to comment Share on other sites More sharing options...
dochubert Posted November 18, 2021 Share Posted November 18, 2021 37 minutes ago, Sid Genetry Solar said: The resistor's placement next to a 2-pin connector AND an LM358 makes it look more like a current sense transformer load resistor. I'm sure you are probably correct. I'm just trying to find something likely, as there should be something for the frequency selection. Actually just found something else. Check this pic of r14 and r12. Below r14 it says "cut if low" My 60hz board has no r12 resistor. Above r12 it says "cut if high". If Felix's board has a resistor in r12 but none in r14 that might explain it. What do you think? Quote Link to comment Share on other sites More sharing options...
dochubert Posted November 18, 2021 Share Posted November 18, 2021 The left sides of r12 and r14 are common and the right sides go to different pins on the processor. Seems to support the theory. Quote Link to comment Share on other sites More sharing options...
Sid Genetry Solar Posted November 19, 2021 Share Posted November 19, 2021 I definitely concur that this could very well be a frequency adjustment 😉. Quote Link to comment Share on other sites More sharing options...
dochubert Posted November 19, 2021 Share Posted November 19, 2021 So now we wait for Felix to let us know if his control board has an r12 resistor or an r14 resistor. Or anybody else with an older 50hz powerjack using a control board older than v4 could give us the same info. Sean might know if he has worked on any 50hz older boards. 1 Quote Link to comment Share on other sites More sharing options...
Felix Posted December 10, 2021 Author Share Posted December 10, 2021 (edited) Guys the inverter is at a remote location. Really sorry for this long delay. So here is pictures of the inside (I know it's dusty...). Hope you will find the info (rev) that you are looking for. It says "HCJ v2.2" close to the Power Mosfets modules... With the picture that you see, is it possible to tweak it from50hz to 60hz? Edited December 10, 2021 by Felix Quote Link to comment Share on other sites More sharing options...
Felix Posted December 10, 2021 Author Share Posted December 10, 2021 @dochubert Here is what I've found (picture below). Seems the same board as yours. And I think it contains the fix of my situation. Should I just desolder the R14 "low F" resistor and resold it to the R12 "high F" holes? I think it could do the trick. What do you think? Quote Link to comment Share on other sites More sharing options...
Sid Genetry Solar Posted December 11, 2021 Share Posted December 11, 2021 Definitely the older boards with the older CPU 😉 My unofficial conclusion: yes, try moving the resistor from the "F Low" to the "F High"...see what happens. Quote Link to comment Share on other sites More sharing options...
Felix Posted December 11, 2021 Author Share Posted December 11, 2021 " 9 hours ago, Sid Genetry Solar said: Definitely the older boards with the older CPU 😉 My unofficial conclusion: yes, try moving the resistor from the "F Low" to the "F High"...see what happens. See what happens sounds dangerous 😂 This said, let me give it a shot and let you know. 1 Quote Link to comment Share on other sites More sharing options...
Sid Genetry Solar Posted December 11, 2021 Share Posted December 11, 2021 1 hour ago, Felix said: " See what happens sounds dangerous 😂 This said, let me give it a shot and let you know. Understood, haha. Big problem is that this board is old enough that it uses the older processor, which I know next to nothing about. I can answer just about any pertinent question on PJ inverters using the Microchip CPU, though. Quote Link to comment Share on other sites More sharing options...
Felix Posted December 11, 2021 Author Share Posted December 11, 2021 Seems to work! @dochubert @Sid Genetry Solar Also, the charging system now works on 60hz. Thanks to all! 1 Quote Link to comment Share on other sites More sharing options...
Sid Genetry Solar Posted December 11, 2021 Share Posted December 11, 2021 I guess you CAN teach an old PJ some new tricks 😉 Guesses were a stab in the dark, but it looks like it worked. Strange though, that resistor (if I'm reading it correctly) is a 10Mohm resistor. Very high resistance. 1 Quote Link to comment Share on other sites More sharing options...
dochubert Posted December 11, 2021 Share Posted December 11, 2021 Well, I'm more confused than ever now. All of my older 60hz control boards had the resistor at r14 and nothing at r12. Felix, moving yours to r12 should have changed it from 60hz to 50hz, not the other way around. I was speculating that yours originally had the resistor at r12 and you would be moving it to r14. Why it did what you wanted, I have no idea. Hope it continues to work for you, but I would definitely keep an eye on it. If there was ever anything consistent about powerjack inverters, it is that they are never consistent. 5 hours ago, Sid Genetry Solar said: that resistor (if I'm reading it correctly) is a 10Mohm resistor. That is correct. 10 Mohms. That resistor was key to high dc voltage trips also. When battery voltage (like mine at that time) hovered around 58v, inadvertant high dc voltage trips happened at times. Very annoying. Some folks put a zener diode across it to stop high dc voltage trips entirely. I changed the 10Mohm to 7.5Mohm on mine, which bumped the trip point up a couple of volts, solving the problem without completely defeating the high voltage trip safety feature. 1 Quote Link to comment Share on other sites More sharing options...
Felix Posted December 19, 2021 Author Share Posted December 19, 2021 @Sid Genetry Solar @dochubert Just want to let you know that it is still working fine on 60hz 🙂 Now here is my next challenge: Increasing from 110v to 120v. Anyone as an idea of a starting point where to look for on this old model? Again, thank you very much for such valuable inputs! 👍 1 Quote Link to comment Share on other sites More sharing options...
dochubert Posted December 19, 2021 Share Posted December 19, 2021 1 hour ago, Felix said: Increasing from 110v to 120v. Sadly, there was no set place or way to easily adjust output voltage on these older control boards. That said, a friend I made on another forum years ago suggested adding a resistor to the series resistor ladder (see pic). You open/scrape the trace between two of the resistors in the ladder, then solder in a resistor of approximately the same value as the others across the open trace you just made. This adds one more resistor in series to the ladder. The pic is from my own 230v control board, and it succesfully raised output voltage to approximately 240v. The resistor ladder is not different on a 110v control board so the same scheme should work to raise 110v to 120v. Be aware that some of these 110v boards were actually 115v boards, so you could get higher than 120v. Possibly 125v. Test before loading! You try this at your own risk. I make no guarantees, especially if you are talking about a 110v board, which I never tried to modify. If you find that voltage is too high, you could always try a different value resistor, say half the value of your first try. Good luck and hope it works for you. Glad to hear also that the conversion to 60hz is still doing good. 2 Quote Link to comment Share on other sites More sharing options...
Felix Posted December 19, 2021 Author Share Posted December 19, 2021 @dochubert You're the best. Let me give it a try and come back to you about it. Thanks again! Quote Link to comment Share on other sites More sharing options...
dochubert Posted December 19, 2021 Share Posted December 19, 2021 Taking another look at my sloppy soldering, as well as powerjack's sloppy soldering, it's a wonder anything worked! Reminds me of the question I never got an answer to years ago when this was going on. Why a resistor ladder anyway? Why not just put one resistor of the total resistance of the series string in and forget the complications of having all those resistors to buy and solder in? Never made any sense to me.... And look at the numbering! They're in series but numbered 248, 233, 232, 241, 262, 259, 246, 247, 260, 261, and 240. And the other ladders' numbering is just as screwy. Another screwy powerjack standard I guess! 1 Quote Link to comment Share on other sites More sharing options...
Joe S Posted December 19, 2021 Share Posted December 19, 2021 a variable resistor there would give you some adjustment. 1 Quote Link to comment Share on other sites More sharing options...
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