15000W LF, 48volt to 240 volt, what wattage?

[Bear]

Hello all, I bought my inverter via ebay, from a guy called David from Taiwan. 

As David was less than pleasant, and after I had the inverter delivered, I decided to re-check what I had bought on Youtube.

In this Youtubers inverter there are 20amp fuses. 20ampsx240volts=4800watts, the video backs up the 4800watts.  💩

My inverter is 240volt no split load, and has 25amp fuses, so 25ampsx240volts=6000. As I haven't got my batteries yet (and plenty of work to do) I haven't tested it yet.

Has anyone else bought this model; what watts have you?

If this is only a 6000watt, what would be a reasonable wattage to take it to?

It makes me angry that I was ripped off, and now laugh at that ridiculous 60000 on the sticker.    

Thank you for any input you can give.

PS is this inverter any good with Lifepo4 batteries?

 

[Sid Genetry Solar]

2 hours ago, Bear said:

Has anyone else bought this model; what watts have you?

If this is only a 6000watt, what would be a reasonable wattage to take it to?

It makes me angry that I was ripped off, and now laugh at that ridiculous 60000 on the sticker.    

Thank you for any input you can give.

Rule of thumb:

• A Power Jack inverter has a sticker wattage of at least double what it can actually sustain.
• A U-Power branded inverter is a Power Jack inverter with a sticker nameplate doubling the PJ nameplate.  In other words, at least 4x what it can actually sustain.  There are no internal changes between an "8kw" PJ and a "15kw" U-Power that I am aware of.  Just the sticker on the top.

 

You basically have an "8kw" PJ that is very likely going to overheat at 2-3kw continuous.  (I know, I know.  Chinese sales tactics!)

Cheers...........yes, that's how it works (or not!)

 

 

2 hours ago, Bear said:

PS is this inverter any good with Lifepo4 batteries?

In what capacity?  Can't recommend the charge/ATS functions, but for discharge you might be able to tweak the "voltage adjust" knob...

....wait, the inverter doesn't have one.

Don't count on the inverter's UVP (under-volt protect) to shut down before overdischarging your batteries, unless you can verify that it does shut down at a decent voltage (with a bench supply).

[dochubert]

Back in 2015 one could safely expect to get 4000 continuous and a few minutes of 6000 to 7000 watts of fairly reliable output from a 48v/15kw powerjack inverter.  We bought them knowing that we weren't getting 15kw. But we were pretty sure of the 4kw continuous, and at a price no one else could match.  Sadly, those days are long gone.  Reaity is that the newer the inverter, the less power you will get out of it.  Cutting corners, sloppy work, no reliable benchmarks, almost no support,  outright lies and great difficulty getting repair parts seems to sum up powerjack's current business model.  There are several companies making inverters loosely copying powerjack's basic low frequency design, which they copied ultimately from Trace/Xantrex.  Growatt, Aims, Genetry, plus a few much more expensive names.  Any of these would be an improvement over powerjack.  Price is the key.  You still can't get a working low frequency inverter at anywhere close to powerjack's price. 

I personally won't buy another new powerjack inverter (and I own several now!)  I will continue to use and repair the older model powerjacks as long as I can keep them working.  I was hoping for awhile to use a Genetry control board to revamp my older powerjacks, but have given up on that idea.  If I could just find someone as smart and talented as Sid to copy and build 4 or 5 version 3.4 powerjack control boards, I could probably make my powerjacks last the rest of my days.

When I just HAVE to buy a new inverter...  Currently watching the reviews for the Growatt low frequency 12kw and 8kw off grid inverters.  The 12kw and 8kw ratings are continuous ratings, and reviews seem to back up that claim.  I've seen no horror stories so far, but they are still kinda new.  Not as cheap as powerjack, but then they're not as CHEAP as powerjack either.   Also I like that you can buy a set of replacement boards right alongside of your inverter purchase.  Now all I have to do is win the lottery....  (probably be tomorrow....)

[Bear]

10 hours ago, Sid Genetry Solar said:

very likely going to overheat at 2-3kw continuous.

Thank you so much for your help.

My wife has just gone ape. HOW MUCH???

Well at least 8000watts is better than the 6000 I thought it was. I suppose adding more cooling fans wouldn't help the situation?

The other inverter I was looking at was the Power Star LW 6000W. I believe this was made in China and not Taiwan; any thoughts on this brand, model?

Thank you again for your help, I appreciate it.

[Sid Genetry Solar]

1 hour ago, Bear said:

Well at least 8000watts is better than the 6000 I thought it was.

Well, an 8kw sticker on a (max) 4kw inverter anyway.  I will be surprised if it can do 4kw without overheating.

 

1 hour ago, Bear said:

I suppose adding more cooling fans wouldn't help the situation?

Unfortunately not.  Sean has seen PJ repair inverters cross his desk where the transformer had caught fire due to overheating...because the customers had unplugged the temperature sensors.

I personally bought a "9kw" PJ several years back (that's what got me connected up with Sean and started the Genetry journey)...it would overheat at 3kw.  I replaced the fans with much faster ones (200CFM), and even mounted the transformer sideways with the fan blowing directly through the center of that hot donut.

...it didn't improve the maximum load before overheating.  Currently am using a transformer that a friend wound by hand...it's SO much better.

 

2 hours ago, Bear said:

The other inverter I was looking at was the Power Star LW 6000W. I believe this was made in China and not Taiwan; any thoughts on this brand, model?

PowerStar W7-series inverters: might do closer to what they claim (I haven't personally used one), but according to TheBackShed forums, their no-load amperage is atrocious.  Expect 2-3 amps no load @ 48v (i.e. 100-150W).  Interestingly enough, the only no-load spec PowerStar provides is "Power Saver Search Mode" (i.e. inverter off, in the 'off' delay timeout before checking for power): "<25W". 

In other words, when the inverter is not producing any output power...it uses less than 25W.  They don't list the on-state no-load power usage, probably because it's so bad.

Power Jack inverters are manufactured in China, not Taiwan.  Gotta love that advertising again...

 

Genetry Solar 6kw inverter for comparison?  I just measured my test bench inverter with the latest Rev. C control board: no-load is 0.4A @ 50v (inverter running 240v out, LCD backlight on, WiFi connected, no fans running)--or 20W no load.  When in software off (LCD on, backlight lit, WiFi connected), it runs 0.06A @ 50v (3W).

 

 

If you just want the absolute cheapest inverter money can buy...any of the Chinese options will probably work (for at least a little while; you should not expect long-term reliability out of any of them.  I've heard several times on this forum that Aims inverters aren't as reliable as people think they are.  Never used one myself though.)  Chinese options being Aims, Sungold Power, Yiyen (manufacturer of most of them!), Powerstar, Solinba, Felicity Power, Must Power, etc., etc. They all have basically the exact same internal design and functions, as you can read on this thread.

 

Now, if you want FEATURES?  (Yes, as the designer, I'm biased 🤣.)  Genetry Solar inverters are LOADED with features and settings that you definitely won't find with any of the "bargain" Chinese inverters on the market.  (Some of the top-of-the-line inverters may have a large number of the same features...at several times the cost.)

For example, how do you change the undervoltage (or overvoltage) shutdown?

• Chinese inverter: You either get a single switch with 2 options...or you don't have any option.
• GS inverter: go to the LCD, and adjust that setting exactly where you want it to protect your batteries.  While you're at it, also adjust the alarm setpoint (where the inverter will start beeping/flashing the LCD and power LED)

How about changing the ATS threshold voltages (when the inverter auto switches to grid or back away from it)?

• Chinese inverter: You're out of luck.  We already gave you a switch to choose between UPS or ATS mode, that should be enough for you.
• GS inverter: go to the LCD, adjust the ATS settings to what you want

Battery charge setpoints?  (Float / Bulk / charge current)?

• Chinese inverter: Best case, you get a 10-position knob to choose between a handful of presets that can't be changed
• GS inverter: go to the LCD, adjust the settings to what you want.  Not to mention being able to manually turn battery charge on or off...

Determining what's going on inside the inverter?

• Chinese inverter: Varies from unit-to-unit...PowerStar W7 you get a series of lights, Power Jack you get nothing...or a simple output load meter
• GS inverter: That little 3.5" LCD has 6 main TABS, with pages, and sub-pages (most of them scrolling)...to access all the stats/settings.  Inverter power stats / temp stats / diagnostic stats, etc.

WiFi connectivity?

• Chinese inverter: either this isn't possible, or you have to buy a dongle
• GS inverter: built-in out of the box.  I shouldn't mention the local network screen mirroring function, where you can control the inverter as though you were literally right there at it. &nbsp;(RV'ers really like this one!)

Auto-restart?

• Chinese inverter: nope, you'll have to manually flip the power switch off and back on to restart it
• GS inverter: go to the LCD, and you can flip on UVP/OVP (voltage) error restart, overheat restart, and overload restart options.  Inverter will automatically restart after the specified delay (assuming the error cause is gone).  Or...you can reset it via the command menu on the LCD...or via the remote WiFi interface (handy for that remote cabin).

Automatic AC input voltage selection (i.e. 120v or 240v)?

• Chinese inverter: never heard of that ability
• GS inverter (with Rev. C control board): built-in.  Yes, I know this isn't fair at all--and most people could care less about it.  But for RV'ers...now we're talking!

Feature requests/updates?

• Chinese inverter: if you can get a feature request actually implemented, let us know: you've accomplished something nobody else has.  Best case, they'll have to send you a new control board, and you'll have to manually replace the one in your inverter.
• GS inverter: OTA (over-the-air) firmware updates to address possible issues / provide new features, etc.  Can update your inverter without turning a screw.
  • I literally added an option to the "Appearance" configuration tab for a customer who lived out of their van--and the flashing power light (Power Save mode) was making it difficult for them to sleep.  So now you can literally turn the power button light off if desired.

 

Yes, I'm aware that we might be tooting our own horn.  But hey, it's the Genetry Solar forums 🤣

[Sid Genetry Solar]

I should be working on soldering together more Rev. C boards for Sean, but...

 

Here's a page on Sigineer's website indicating the "no load" and "power save" consumptions for THEIR inverters: https://www.sigineer.com/features/power-save-mode-power-saver-off/

Of particular interest to me were the 6kw and 12kw lines...

Quote

Model | Power Saver Off | Power Saver On
6KW    |         90W             |           25.0W
12KW  |         180W            |           40.0W

I would expect most similar Chinese inverters to have similar quiescent power ratings.  From what little I've been able to read, PowerStar losses might be double the Sigineer ratings.

 

But then let's do a comparison to the GS inverters as tested currently:

Model | Power Saver Off | Power Saver On
6KW    |         20W             |           3.0W
12KW  |         ~30W            |           3.0W

 

And of course, how about this for the "coup de grace"??

Quote

 

Note: The minimum power of a load to take inverter out of sleep mode (Power Saver On) is 50 Watts. For split phase models, the power threshold of sleep mode is 50W between Hot1 and Neutral and 200W between Hot 1 and Hot 2. There is no load detection between Hot2 and Neutral.

Note: The minimum power of a load to take inverter out of sleep mode (Power Saver On) is 25 Watts.

 

GS inverters?  True split-phase power monitoring AND load detection.  GS inverters will detect (and properly measure) a load on any combination of output phase usage.  L1-N, L2-N and L1-L2...

GS inverter minimum load wattage?  You decide...configure it anywhere from 5-320W.  (And that's only because I've limited it to said range--actual range can be anywhere up to the full rated load of the inverter.)

 

Yeah, I'm biased 😉.

[Bear]

Thank you all for your help.

What a downer. 🙁

It does supprise me that there are none for sale second hand on ebay, or even as spares and repairs.

Hey Ho.

[Sid Genetry Solar]

5 minutes ago, Bear said:

Thank you all for your help.

What a downer. 🙁

Hey, I'm just trying to be realistic, so you aren't disappointed or caught off guard in the end by something the manufacturer didn't mention.

I actually sold the first inverter I bought (a high-frequency Meanwell TS-3000) for one reason: I couldn't adjust the OVP (over volt protect) level above 58v.  Here I am with lead-acid batteries and the inverter datasheet indicated max of 62v.  And it was shutting down at 58v, with no way to change it.

 

5 minutes ago, Bear said:

It does supprise me that there are none for sale second hand on ebay, or even as spares and repairs.

Of what?

[InPhase]

What is it that's going on inside those Chinese inverters that keeps their no-load draw so high?

[Sid Genetry Solar]

42 minutes ago, InPhase said:

What is it that's going on inside those Chinese inverters that keeps their no-load draw so high?

What I can't figure out is how their "power save idle" current is so high.  Even if they properly calculate the wattage while keeping the "on state" to "off state" ratio in mind...I still don't know how they can burn so much power in idle state.

Likely the biggest cause has to do with either the fact that they're using low quality square transformers (instead of a toroidal transformer like GS, PJ, and reportedly Victron)...and/or that they don't have any ferrite choke between the FETs and transformer.  (I haven't seen any ferrite choke in internal photos of PowerStar or other inverters.)  Basically, this ferrite choke absorbs/filters the 24KHz SPWM carrier, leaving more of a 60Hz fundamental for the main transformer--instead of letting the transformer burn up that carrier in heat (and wasted power).

If I remove the ferrite chokes on a GS 6kw inverter, I believe it will go from 0.4A no load to well past 3A no load.  Haven't tried it, but I wouldn't be surprised.

[TheButcher]

5 hours ago, Sid Genetry Solar said:

Yes, I'm aware that we might be tooting our own horn.  But hey, it's the Genetry Solar forums 🤣

 

Toot away as loudly as you can.  It's the only way to overcome the din of the Chinese manufacturers, point in case this very thread.  People keep buying them because they either don't understand the problems they all have, or don't care.

Yes, Victron uses toroidals, very neatly wound ones at that.  I think their most recent slim case designs use two in parallel to allow the form factor.

[Sid Genetry Solar]

10 minutes ago, TheButcher said:

Toot away as loudly as you can.  It's the only way to overcome the din of the Chinese manufacturers, point in case this very thread.  People keep buying them because they either don't understand the problems they all have, or don't care.

My point was to be up front that I'm not speaking from an unbiased position.  Truth in advertising, if you may.

 

Yes, most people buying cheap Chinese inverters normally do so solely from a price perspective, without considering the realities or fine print of said products. 

To be honest, so did I when I bought my first (and only) 9kw v9.0 PJ several years back.  Bought it not expecting much--and boy was it so much better than the SwiPower 3kw HF inverter it replaced.  (Cost 3x as much though, though ending up only providing the same wattage output!  Still: you get what you pay for!)

[TheButcher]

4 hours ago, Sid Genetry Solar said:

I would expect most similar Chinese inverters to have similar quiescent power ratings.  From what little I've been able to read, PowerStar losses might be double the Sigineer ratings.

Certainly the case for sungold power.  There's been a spate of 'reviews' recently on social media of this brand.  99% of them are complete fluff, even the longer reviews, but every now and then someone does do a basic proper review with actual test measurements and finds idle draw to be north of 100W for a 6kW model.  Inverter might be cheap, but not so cheap overall when you need to add on another 1.5kWh of storage just to run the inverter overnight.  But it has a 20W 'low power mode', I hear people cry.  Well that's nice, but still only bringing it into the run mode draw of decent inverters and a mode of operation that most people can't use anyway since the typical use case requires AC power on at all times.

[Sid Genetry Solar]

39 minutes ago, TheButcher said:

But it has a 20W 'low power mode', I hear people cry.  Well that's nice, but still only bringing it into the run mode draw of decent inverters and a mode of operation that most people can't use anyway since the typical use case requires AC power on at all times.

Power Save mode is pretty much a vestigal dinosaur function these days.  I've hacked my house appliances to run all the CPU stuff on 12vDC...and so yes, I can use power save mode on my inverter.  But the average Joe with a solar system will find that their refrigerator won't run, their microwave clock always resets, etc., etc., etc.

I still have a hard time figuring out where they're burning 20W in off state (which is the no-load power of a RUNNING Genetry Solar 6kw inverter!)  Figuring out the 100W isn't hard...it's the 20W I can't figure out.

 

100W quiescent current is pretty sad.  That's the ENTIRE amount of power my 3kw solar array puts out on a really cloudy day here in Ohio.  (I have 11kw total, but the single 3kw I started with is still a pretty good benchmark.)  Not to mention that a 5' chest freezer (or 29 cubic-foot French door 'fridge) each use just over 120W to actually do something useful.

[TheButcher]

The only thing I can come up with is a linear regulator and a total LV side draw around 1A.  24 Vbatt, 5W to the circuitry, 15W to heating up the air.  That would also explain the increased idle draw for higher batt voltage models.  At nom 48V, about 50W dissipated, 5 to the load, 45 to heating up the air.  I can't see a regulator with sufficient heatsinking in the pictures of the ones I've seen though.  It might also be that they use a bypass resistor to provide must of the current with a linear regulator supplying the remainder to keep regulation.  If there is a chunky power resistor on the board that would be a likely candidate.

Who would use linear regulation in such a situation?  Someone that only knows how to copy things and make the occasional idiot design change, just like the typical manufacturer of these things ...

[Sid Genetry Solar]

1 hour ago, TheButcher said:

The only thing I can come up with is a linear regulator and a total LV side draw around 1A.  24 Vbatt, 5W to the circuitry, 15W to heating up the air.  That would also explain the increased idle draw for higher batt voltage models.  At nom 48V, about 50W dissipated, 5 to the load, 45 to heating up the air.  I can't see a regulator with sufficient heatsinking in the pictures of the ones I've seen though.  It might also be that they use a bypass resistor to provide must of the current with a linear regulator supplying the remainder to keep regulation.  If there is a chunky power resistor on the board that would be a likely candidate.

Who would use linear regulation in such a situation?  Someone that only knows how to copy things and make the occasional idiot design change, just like the typical manufacturer of these things ...

Very fair assumption, it'd make a lot of sense.

However, ALL of the LF Chinese inverter control boards I've seen (covered on another thread) use the EXACT same switching transformer-based power supply for the +12v supply (same as PJ, mind you).  The transformer has 4 secondaries: 2 for the high-side FET drive supply, 1 for "main 12v", and another for negative voltage (used for the op-amps.)  But PJ puts a heatsink on the drive FET, indicating significant losses there, so........

...though it seems the older PJ designs used a zener diode across the 2 high-side FET drive supplies to limit the voltage (said zener diodes simply nonpopulated on the current boards).  If the little transformer is pretty lossy, that'd explain a decent amount of loss--but not more than 2-3W (because said diodes can't dissipate more than that!)

[TheButcher]

It'd be interesting to see what a thermal camera shows.  Those watts have to be going somewhere.  Unless it's a lot of somewheres 15W is going to make that thing quite toasty.  Exceedingly poor design for the LV switching supply?  I guess they could have ultra bad drive for the FET (presumably they use a FET there) and it's running in the linear region instead of hard on / off?  Losses in that transistor, the switching transformer, slow rectifier diodes, the clamp diodes on the FET drive supplies.  I guess they might actually get to 20W if they tried hard.  An achievement of a type, but not something to admit to!

[Sid Genetry Solar]

7 hours ago, TheButcher said:

Exceedingly poor design for the LV switching supply?  I guess they could have ultra bad drive for the FET (presumably they use a FET there) and it's running in the linear region instead of hard on / off?  Losses in that transistor, the switching transformer, slow rectifier diodes, the clamp diodes on the FET drive supplies.

That's highly possible--PJ uses an IRF630 (9A) or IRF640 (18A), directly driven by a UC2843.  I don't see why the FET should need a heatsink, unless something's really wonky with the drive.

 

7 hours ago, TheButcher said:

I guess they might actually get to 20W if they tried hard.  An achievement of a type, but not something to admit to!

Hehe, agreed 😉.

[Paul]

I know people love to slag off the powerjack/upower inverters (often quite rightly so!) but my experience has not been so bad.

My first foray into off-grid power started in 2018 when I obtained from a friend's deceased relative a 2013 PJ 8k 24v-230v inverter (not split phase). Inside it had a V3 (I think) control board, two AS2 ( I think) transformers in series, and a few modifications including 45C thermoswitches bolted to the FET heatsinks to operate the fans, and a manual fan override switch. This inverter is still working today although no matter what chokes I have tried it still draws about 2.5A (~50W) at idle. The inverter function worked well but the charging function went wookie unless the fans were running. I discussed this in another post... I've since changed the fan override switch to run fans at about half-speed until the thermoswitches turn them to full power. This unit produces a very clean sine wave output all the way up to at least 3.6kW before the overload LED comes on. I've not ran it at this power for more than 20 mins and not tried to go above this as it meets my needs and as it has survived 8 years already I don't want to blow it up for the sake of testing loads which I will never run it at. I used it throughout this summer but the idle consumption is an issue during winter here where there is little sun.

Shortly after this I obtained a 'ProMariner' branded 2kW PS unit. This was insufficient for our needs and although I didn't have an oscilloscope at the time it was noticeably weaker than the powerjack e.g. the microwave would take longer to cook stuff than when running on the PJ.

In November 2020 I bought a secondhand Victron 3k unit. I wasn't sure of the exact age but it worked perfectly for about 2 weeks after I bought it. It never got loaded much above 2.5kW, and all the cooling fans were working so I am not sure why it failed but it did fail. It started of by intermittently refusing to power up the output stage, giving an 'overload' LED even when there was no load, until a day or two later going straight to 'overload' without even powering up the output stage. I tested the transformers and FETs and they were fine, so I concluded the fault was on the control board. The control board was very complex and antiquated looking with a lot of ancient DIL logic IC's and a lot of very neatly wired, probably factory rework on the back of the board. I contacted Victron but they just said the unit was obsolete and there were no spares or support for it.

So as by now although the old PJ still worked, I still wanted a newer and more efficient inverter, In January 2021, I bought a 'upower' 8kW unit, knowing that at best it would do 3.6kW like the ancient PJ. This had rev 10.3c boards but was slightly lighter in weight than the old PJ 8k as it has a single ASL3 transformer rather than the two AS2 transformers of the old unit. I observed on the scope significant flattening of the sine wave peaks with loads above about 1.5kW but it still tolerated loads of 3.6kW for 20 mins without any alarms or shutdowns. But when spring came I put it aside and resumed using the old 2013 PJ. Recently by removing one turn from the primary windings I have reduced the severity of the flattened peaks, but they are still there. However I can tolerate this during winter as it draws only 0.9A at idle instead of the 2.5A of the old PJ and the difference in 'real world' performance e.g. cooking, washing machine, etc. compared to the older PJ is negligible. As with all my inverters, it gets swiched off during night for the 7 hours where we have cheap-rate grid power (called Economy7 in the UK).

Having since learned about the GS units I would have opted to buy one of those but as they don't ship overseas due to complexities of customs paperwork, cost, etc, PJ/upower units are the best performance per buck that we can get in the UK. I have been lucky, but as has been said many times on this forum it can be pot-luck what you get with these chinese vendors.

As a semi-competent electrical engineer, I bought a complete set of PJ boards (11.1) and using formulae available on other forums wound my own transformer on a 52cm2 toroid core. This gave a near-perfect sine wave up to 3.6kW and the transformer barely got warm even after 20 minutes with no cooling fans (the fans only cooled the main+control boards). However like the old PJ it drew a stubborn 2.5A at idle. I tried two full turns on the late PJ/upower ferrite rings as well as other choke configurations but it was either the same or worse idle consumption. In the end I found the best chokes were some random E-I chokes I recovered from a decommissioned 48v rectifier. One choke would have been sufficient as the copper strip they were wound with was perfectly capable of 150A+ without getting hot. But the lead-in cables were only 13mm2 so these got hot. It was impossibble to replace the lead-ins without destroying the chokes. Therefore I had to put two in parallel. With fan cooling these remain at acceptable temperature with sustained 3.6kW load. And the idle current is about 1A (25w) which is also acceptable. I have the housing for this project but just haven't got around to it yet!

 

[Sid Genetry Solar]

6 hours ago, Paul said:

My first foray into off-grid power started in 2018 when I obtained from a friend's deceased relative a 2013 PJ 8k 24v-230v inverter (not split phase). Inside it had a V3 (I think) control board, two AS2 ( I think) transformers in series, and a few modifications including 45C thermoswitches bolted to the FET heatsinks to operate the fans, and a manual fan override switch. This inverter is still working today although no matter what chokes I have tried it still draws about 2.5A (~50W) at idle.

From what I've heard, the older PJ inverters (< v5 for sure) were very reliable.  Also IIRC they don't use a Microchip PIC MCU...indicating a different firmware.

While the control board circuitry on the latest PJ designs is definitely problematic, I am actually pretty sure that a lot of the "charging" woes on the latest PJ inverters is due to firmware issues.  The core control board design concept really hasn't changed much from v2 all the way through v11...just there's been a lot of added "fluff" that is really just Band-Aids around firmware issues.

[dochubert]

20 hours ago, Sid Genetry Solar said:

From what I've heard, the older PJ inverters (< v5 for sure) were very reliable

The Version 3.4 powerjack control board seems to be the best one.  If someone were to copy that design without 'improving' it, they would have me as a customer for at least two of them.  Probably more.  I can't be the only owner of older powerjack inverters who would happily pay a reasonable price for a truly reliable control board that would restore those inverters to working order (without having to 'update' them).

Since powerjack copied the design from someone else, shouldn't be any legal issues.  If it is a concern, adding a potentiometer to allow output voltage adjustment, which the v3.4 didn't have, would change it enough to avoid that concern.  And/or just completely eliminate the charging function, leaving off all of the parts related to charging, making it simpler and cheaper to produce.  More powerjacks have likely been blown by people trying to charge batteries than by all other reasons combined.  Serious solar power producers don't use the charging functions anyway.  That's what solar panels are for!

(I know.  I said I didn't want it improved.  Then I went ahead and suggested two or three improvements.  Guess I'm no better than the other guys.)

[Sid Genetry Solar]

1 hour ago, dochubert said:

The Version 3.4 powerjack control board seems to be the best one.  If someone were to copy that design without 'improving' it, they would have me as a customer for at least two of them.  Probably more.  I can't be the only owner of older powerjack inverters who would happily pay a reasonable price for a truly reliable control board that would restore those inverters to working order (without having to 'update' them).

The only significant difference on the FET drive between a GS controller and a PJ inverter...is that one's perfectly balanced and more than strong enough--and the other one isn't.  Yes, the PJ inverters use a floating high side drive method...but that does not figure into the actual performance.

I can technically make a very imbalanced and weak driver for a GS inverter to approximate the same effect...

 

You don't have to go very far to find a "copy" of the older PJ board design: pretty much ALL of the cheap Chinese LF inverters use pretty the exact same PCB.

They also don't have very high reliability marks.

 

1 hour ago, dochubert said:

More powerjacks have likely been blown by people trying to charge batteries than by all other reasons combined.

This likely has to do with the CPU firmware first and foremost, with the AC input handling being second (i.e. split-phase AC backfeed due to the inverter only disconnecting L1.)  A distant third would be the weak FET drive control (i.e. crosstalk / EMI weak-triggering FETs, etc.)

[dochubert]

Sid, you are a much better tech than I could ever pretend to be, so I can't argue with your statements.  All I can do is assert that an older powerjack with a version 3.4 control will run strong with clean output and reliably for years, while that same powerjack 'updated' to newer controls will run much weaker (poorer sine wave over voltage range and lower power handling capability) and generally fail in a much shorter time.

Does it make sense?  I can't explain it.  But it is an observation, not wishfull thinking.  The wishfull thinking comes when I wish for a few more v3.4 control boards.

[Sid Genetry Solar]

1 hour ago, dochubert said:

All I can do is assert that an older powerjack with a version 3.4 control will run strong with clean output and reliably for years

No question there.  I personally believe the "clean output" has a lot more to do with the transformer ratio, than the control board--as on the newer inverters PJ tends to run higher and higher transformer voltage specs.  This causes them to "flat-top" sooner--but according to PJ, it reduces the number of inverters that blow up

 

1 hour ago, dochubert said:

while that same powerjack 'updated' to newer controls will run much weaker (poorer sine wave over voltage range and lower power handling capability) and generally fail in a much shorter time.

Wouldn't be surprised if this has to do with not only FET resistors / FET choices, but also the added "garbage" between the CPU and the driver board in the more recent versions.

[Sid Genetry Solar]

Worth noting: I personally was astounded when testing the first GS boards (and even to this day).  Take a PJ inverter: the transformer has a very definite hum/buzz that we're all very familiar with.  (The newer ones have a double hum...the 60Hz hum with a 30Hz regulator oscillation superimposed on it, which causes flickering in sensitive lights.)

With a perfectly balanced/matched GS driver, etc., etc. the transformer will be almost DEAD SILENT.  To the effect of, "Well, I turned the inverter on, but it evidently isn't working."  Then put a meter on the output and, "Whoops, wait a minute, it IS running!"

Not to mention the 12kw GS inverter when running at high load...the transformer is getting hot and all, but the FETs were basically room temperature at 10kw (obviously, this was with a single high-speed fan blowing through the heatsinks).

 

Maybe I'll be able to work something out to get you a GS setup just so you can see how much of a difference it makes.  Not like I don't have repaired/reject parts around that I can't pull something together that otherwise would just sit around...