Author Topic: guess who bought a power jack inverter  (Read 196502 times)

0 Members and 1 Guest are viewing this topic.

Offline oztules

  • Moderator
  • Hero Member
  • *****
  • Posts: 1177
  • Karma: +105/-8
  • Village idiot
Re: guess who bought a power jack inverter
« Reply #15 on: April 21, 2014, 05:22:14 am »
No.
The powerstar needs better transformers... the choke will not help with those lossy monsters.Torroids give the best results, but EI transfromers with decent laminates do well also..... but not the powerstar ones I'm afraid.


.............oztules
Flinders Island...... Australia

Offline lighthunter

  • Sr. Member
  • ****
  • Posts: 323
  • Karma: +13/-0
Re: guess who bought a power jack inverter
« Reply #16 on: May 04, 2014, 03:21:56 am »
@ oztules or anyone who has pwrjack. I recently puchased 6000LF
Very happy with so far your review helped to make decisions.
Thanks so much for your post!!!!

 I only loaded it to 1500w so far and ran ac unit great. It only has 1 toroid
Unlike the 2 in your 8000LF. That makes sense of course however the.
Fuse leading to outlets is only 25amp. Maybe i've forgotten ohms law.
But wouldnt that make max load 3000watts at 120v? Thought just
Hit me maybe if it was 220 volt it would b 6kw? Anyway im happy price
Was right at 405 shipped. Idle current is 1.63A at 26v around 40watt.
Do you think id gain much efficiency at idle with ecore mod? Maybe.
22 watt like yours?
Health Warning: May contain traces of nut!
LH

Offline lighthunter

  • Sr. Member
  • ****
  • Posts: 323
  • Karma: +13/-0
Re: guess who bought a power jack inverter
« Reply #17 on: May 04, 2014, 03:43:09 pm »
Ok i couldn't wait. The :o ecore i ordered rom ebay hasnt arrived yet.
 i took the cover off again.... measured no load idle current at1.63A then noticed low voltage toroid wdg lead had a ferrite donut surrounding the 3 wires. There was just enuf room to unscrew.
The terminal and loop those 3 wires through the ferrite again. Measured no load current again.
Now its .92A. I then checked values under load, 945W output input
22.1V@41.3A took the extra wrap out of donut measured loaded 946W.
Output input 22V@45amps. Efficiency gain of a clear 4 percent. Wow
I dont completely understand it but good job in figuring that one out.

This unit is definately only a 3KW as configured to 120v but am happy.
With it maybe they figured i got it too cheap and boxed a 3K in 6Kwrap.
I drew out circuit and fets are irf3205 6x4 H-bridge what i dont understand
Is how u can power the toroid backwards and charge a battery since the.
Fets have freewheel diode i would think battery chg would b uncontrolled thru.
Diodes. By the sound of charger it sounds like fets are switching at high freq for
Charging. By the way im from Minnesota USA ..reason for 120v i know 220 is.
better in every way.
Health Warning: May contain traces of nut!
LH

Offline Norm

  • Sr. Member
  • ****
  • Posts: 475
  • Karma: +26/-0
  • Today is the day you worried about yesterday.
Re: guess who bought a power jack inverter
« Reply #18 on: May 05, 2014, 06:38:08 am »
I'm new at the term power jack inverter.....is this what you need for emergency
power to run freezer and refrigerator....and what would be the practical size ....
just to run the two assuming the largest size for a 2-4 member family ?

Thanks for answering . :)
Norm.

Offline oztules

  • Moderator
  • Hero Member
  • *****
  • Posts: 1177
  • Karma: +105/-8
  • Village idiot
Re: guess who bought a power jack inverter
« Reply #19 on: May 05, 2014, 02:05:06 pm »
The 6000lf should have two transformers in it. Powerjack transformers are a bit small for continuous duty at full power, so they limit it via software.
This tends not to be problematic in 99% of cases, as most folks don't have the batteries to run them for extended periods at full power... ie 6kw would be 240 amps plus losses continuously.... never seen  a 6KW single transformer one. 5kw unit has only 1 tranny.

My 6000 has two "3kw" transformers. Transformer wattage is dependent on the heat  only. A small tranny well cooled is equivalent to a big one not cooled at all( plus some voltage sag).... so it should be good for 3-4kw most of the time.

If you want more continuous, you will need to use bigger transformers, and fool the current transformer into thinking less current.....ie bypass some of the current around the CT.
The mystery of the lower idle current seems to revolve around the inductance ( current lags) giving the mosfets time to turn on fully before the current comes on fully, so our switching losses in the fets diminish rapidly, and so does the heat.... It certainly seems to run cooler.

It is a function of H bridge switching that the current will run back through the fets if the potential is higher than the drive. This turns up in most DC pwm motor controllers and is touted as active breaking... ie charge the battery with the braking energy. The switches are switches, and can run the current either way once the N channel is turned on... so through the transformer and backwards through the switch to the battery.

When we use it as reverse grid tie ( off grid), the same thing happens, but now the micro does not know we are doing it, so it cannot control the charge, and it needs a dump or cut off switch for the grid tie unit. The micro is still responsible for the sine wave... thats why it cannot control the reverse current for the batteries.

In normal charger mode, it bypasses the inverter function, and powers the load from the generator/grid, so is not responsible for the wave form of the output. This leaves the micro free to control the gates to feather the charge to whatever it wants, and does not have to worry about output waveform.

The fuse is about right for 3kw continuous. It will blow in about 2 seconds at 6kw. The micro won't let it run that hard for that long, so it is probably about right for a 3kw continuous unit, that will start very heavy loads for short times.... ie compressor motors etc..... It looks like it has the bigger brother stickers on it..... but still a great unit for the price.

You will get it down to about 16 watts or so  with some inductance on the input to the trannies.. maybe 18 uh or more....only 1 transformer mass to magnetize.

Power jack do themselves no favors with this type of behavior,they build to price from the looks of it... buy cheap, smaller trans, buy the dearer one on auction, may get bigger transformer... I don't know, but I bought a very cheap 8000lf, but it had 2x 3kw trannies ... with black  texta over the 3kw sticker on the torroid itself..... they should have been the 5kw ones like my original one.... but I paid more for that one too..... the smaller trannies work as well as the 5kw ones do, but it has tighter software control.... less minutes at full power....

But they are still brilliant value anyway, and plenty tough too. Can replace the 3205 with irfb4110 and bypass the CT and push for 8kw 80% duty cycle.... if you can keep the tranny cool that is.

In Australia, there is a heap of very very cheap torroid transformers on the market at the moment, and this makes it very interesting as what to build next.. sky is the limit.

Norm, the 3kw units will do that easily. Powerstar have the same electronics, but slightly different software, and their continuous output is higher, as the software allows for bigger ( though less efficient) trannies. They won't respond to the inductance trick either..... only high quality transformer laminates will do that.



.....................oztules

Flinders Island...... Australia

Offline Norm

  • Sr. Member
  • ****
  • Posts: 475
  • Karma: +26/-0
  • Today is the day you worried about yesterday.
Re: guess who bought a power jack inverter
« Reply #20 on: May 05, 2014, 05:53:11 pm »
yep aat the moment the neighbor doesn't bother with all that
Lot of money and the stand by emergency generator does that
without a lot of know how on his part  :)
so I'll just let it go at that
I don't have a freezer but a lot of ice in my big freezer in refrigerator
to keep it cool enough for eggs, milk and butter , etc.
thanks for the answer
Norm.

Offline lighthunter

  • Sr. Member
  • ****
  • Posts: 323
  • Karma: +13/-0
Re: guess who bought a power jack inverter
« Reply #21 on: May 08, 2014, 06:15:13 am »
Wow! Im amazed at your explanations Oztules, not many who understand.
All that stuff. The charging reference to dynamic braking helped.
Me understand it. For some reason braking always has made sense to.
Me but i never connected the two (bkg and chg) as being the same function.

Yeah pwrjk is great value but it would be great to know specs for.
Sure when u purchase. Thanks for pointing out simple mods to.
Increase output if needed. Split phase 120/240 would be great.
Addition too! by the way i noticed that pwrjk has sold a few split phase.
Units lately not often though!
 
THANKS AGAIN for excellent infomative post! :)
Health Warning: May contain traces of nut!
LH

Offline lighthunter

  • Sr. Member
  • ****
  • Posts: 323
  • Karma: +13/-0
Re: guess who bought a power jack inverter
« Reply #22 on: May 16, 2014, 12:02:09 am »
I finally got ecore,also ordered a couple of 2" ferrite.
Toroid cores like these
 http://m.ebay.com/itm/181410431240.
I was able to get one of these inside the box with.
2 turns. Idle current went from original 1.63A down to.
.54A. roughly 42watts down to 13-14watts. My meter could.
Be off a bit too but i'm very happy with it and impressed thanks.
To your help, much appreciated! :)    (i only went with toroid core.
Cuz i could fit in box without lengthening lead wire.) This unit.
Wont be idling much anyway as i have programmable relay switching.
It off when no loads are transferred to it. I noticed that adding the inductance.
Not only helps idle efficiency but it also improves losses under load.
Health Warning: May contain traces of nut!
LH

Offline lighthunter

  • Sr. Member
  • ****
  • Posts: 323
  • Karma: +13/-0
Re: guess who bought a power jack inverter
« Reply #23 on: May 16, 2014, 10:23:33 pm »
Just want to update results from 2"toroid. While under a 1kw load the inverter started
Screeching really loud. I took cover off to see what racket was all about and found when i
Squeezed toroid core the pitch of sound changed then it started getti g hot. I turned off switched to the ecore and it was fine. The toroid core mustve been broken inside or maybe not ferrite at all but rolled tin and it had shorted turns
Health Warning: May contain traces of nut!
LH

Offline oztules

  • Moderator
  • Hero Member
  • *****
  • Posts: 1177
  • Karma: +105/-8
  • Village idiot
Re: guess who bought a power jack inverter
« Reply #24 on: May 17, 2014, 05:40:13 pm »
The torroid core will saturate very early  on in the power range, thats why an ecore is better with a gap.... it will saturate too ( I ran it at 10kw the other day for a short time (5 mins) ... but it will still keep the magnetising losses to a minimum, and this translates into a 300w plus saving for a 48v system.. right through the power range as you have found.



I find that if I super glue the ee's the heavy battery cable wound through it stops any noise.... otherwise it is very noisy.

That torroid looks fairly light, do you know the inductance of it? 18-20uh seems in the right area.

I may have to do another story on these things, as lots has been learnt since writing this.

If you wind your own transformers like I have done, it is important to get the phasing around the right way for the ac coupling to work properly... or it gets very untidy quickly.

These power jacks have a very nice control card that lends itself to very high power if you have the transformers to take it, and the fans to keep it cool.
They are simple and very very tough. You need to stick a screwdriver in the wrong place to get them to fail.

Bypassing some of the current around the current transformer gives you access to lots of grunt..... and I mean lots.


.......oztules
Flinders Island...... Australia

Offline BerryG

  • Newbie
  • *
  • Posts: 1
  • Karma: +0/-0
Re: guess who bought a power jack inverter
« Reply #25 on: May 21, 2014, 08:46:16 pm »
Good day everyone, I stumbled on your forum while looking for a way to solve issues with my PSW7 5000W inverter.  I've had it since Nov 2013, and I use it on a solar system 48v input, 220V split output at 50Hz here in Jamaica. Just recently it started to shut off after 5mins of use, no fault lights or anything, just seems to be running as normal, but no output, even when I restart it.  Correction, it  actually didn't shut off, it just stop sending power after 5 mins or so. Now it will not work at all. It needs a new control board and I should be all set, but my second issue is that I don't know how much power its using at idle, but based on my read up, its quite a lot. So first thing is that I need help finding parts and second is how to get it to use less at idle. otherwise I'm gonna have to get one of those magnum units at lots of $$$$...
 
Can anyone help on these issues, especially parts.
Its a PS W7 type inverter, 5000W 48V, 220v split output at 50Hz. Two IE transformers.
No display on the unit, just status LEDs.

 Thanks, Geoffrey.

Offline oztules

  • Moderator
  • Hero Member
  • *****
  • Posts: 1177
  • Karma: +105/-8
  • Village idiot
Re: guess who bought a power jack inverter
« Reply #26 on: May 22, 2014, 01:51:36 am »
Check your reset switch for continuity.
Is the fan running at the transformer end
Is the small fan running at the front end
Do any lights come up.
Are the heat sinks warm.

If the big fan at the rear is working, it is making power, as that fan runs on the output AC
If the small fan is running, it means the pwm power supply for the control board is working, and so are the two high side drive power supplies. All run off the same transformer.
A faulty tacho output signal in the small fan will stop it dead too.

Tell me as much as you can as to what bits run, , what fans are running if any, what lights are showing if any.

It is a good solid performer normally, but high power overheads.
If you can use it on search for intermittent loads then it is about 25 watts, if running full time, it will consume 4 amps of your 48v battery all the time, on top of any loads.

You need high quality transformers to stop this power loss.

You may find them in old welders, as they seemed to be better built back in the day, but they will be better than the ones in the unit.... you may get it down to 60 watts or so with them

The ideal is to get a torroid transformer with about 30v input and 220v output. This can be very expensive, unless you can find some grid tie inverters of the heavy kind. They use huge torroids, and can be rewound to do whatever you want.... usually we keep the inner winding and just rewind the primary with battery/welding lead  cable.
With a decent torroid the power loss can be as low as 20 watts.
Try to get this one working first..... but if you need new boards and can't find them, then the powerjack LF control boards can be used with small changes... they are on Ebay for about 45 USD plus shipping.

But first .... how does it start up step by step, and what is actually running if anything.

..........oztules
Flinders Island...... Australia

Offline steve3

  • Newbie
  • *
  • Posts: 20
  • Karma: +0/-0
Re: guess who bought a power jack inverter
« Reply #27 on: July 25, 2014, 06:13:34 am »
Hi guys Im looking to make the choke three and a half turns 18 mh core you say sounds simple, but I cant seem to get hold of one in England (any help please).
You said running at 8 kw the amps would be about 300 amps is the 8000 LF that good, sounds low to me.
I like the idea of being able to read the battery amps, any help would be great, Email would be brilliant.
Any ideas running 8000 w LF with a 3650 w PV system grid tie.
Fab thread very interesting. best to all. Steve.


Offline oztules

  • Moderator
  • Hero Member
  • *****
  • Posts: 1177
  • Karma: +105/-8
  • Village idiot
Re: guess who bought a power jack inverter
« Reply #28 on: July 25, 2014, 07:02:16 am »
Yes that was my original 24v unit. Normally it ran at 28vdc so 300A would be close.
With a standard power jack, you will do this for 12 seconds and it will beep and shut down...... not because the electronics can't stand it, but the transformers won't do that for long.... I ran that for testing, I now am back to 48v systems.... have 4 of them now, 2 power jack originals, and 2 powerjack control and power boards with serious transformers in the old grid tie boxes.

Nominally it is really only about 3kw continuous... after that it's programming protects it from excessive heat build up in the transformers.
The electronics are good, the programming is to safe for power users, as the transformers are too small for long run high power.

I build much bigger transformers capable of 8kw continuous out of old galvanically isolated grid tie units... they have very good torroids, that are rated and run at 3kw continuous all day with no cooling. I use 2 or 3 of them stacked and rewound for high power continuous. The  failed/ broken aerosharps here are cheap I bought 10 x 1.5kw units for 400 dollars.... the cores are good for 2kw or so continuous...... The inspire ones (1.5kw) have 3kw cores in them, and so rewinding with 2 stacked, gives an easy 6kw continuous..... but you have to fool the current transformer by bypassing some of the current around it with a shunt. That way the thing will do continuous high power, rather than the 12 seconds.... you need a serious battery pack to do that though.

The surge currents are huge for starting stuff up... I mean huge.

If you beef up the transformers, 3-4kw solar grid tie is no problems, we have one here that runs 3 x 1.5kw grid ties every day.... BUT it requires the current shunt, and rigging the fan for continuous operation, as the computer will not see the current draw and so not turn the fan on until it is too hot anyway.

The electronics are good, and by beefing up the tranny, and current bypass and cooling, they will give the bigger name brands a very serious run for the money.

In their native state, they are excellent 3kw units, not 8kw units, although the surge is very impressive. Buying the 15kw control card for 45 dollars is a good lurk for those running 48v, it saves shunting the transformer, so the computer still does a good job with the fan control, but then best to upgrade the transromers, or they will over heat in continuous mode.... 15kw card is good for about 5kw continuous without modification.... the 15kw power board is electrically the same as the 8kw power baord, but physically twice the size to spread the heat better.
I have bought the 15kw power card as well, but have not bothered to press it into service as the 8kw with the changes is easily big enough to run my house including electric hot water unit... it runs the 15kw control card at the moment.

I have seen break down ( explosion of fets) caused by turning off the grid "shore power) while running the grid tie into it without a house load.

So AC coupling to shore power input I think has some further testing and blowing up before I can say for sure why that happened..... at least they mostly  are easy to fix... if you fuse the input properly... then hopefully the fuse will blow during the fet meltdown, and the tracks up on the control card don't get cooked as well. If the fuse blows it will be just the fets, some gate resistors, the totem pole transistors and the 2 opto's, which are plugged in in the newer models........ sometimes it is just the fuse..

Yes i have done some truly horrible things to these unit to see what happens.... and sometimes because of simple stupidity.

They have never blown driving a huge load..... mostly with no load while I have been trying stuff I shouldn't......not too bright.


I will endeavour to answer questions on the board, not privately.... no one else learns anything that way.


.......oztules
Flinders Island...... Australia

Offline steve3

  • Newbie
  • *
  • Posts: 20
  • Karma: +0/-0
Re: guess who bought a power jack inverter
« Reply #29 on: July 26, 2014, 06:35:53 am »
Hi guys I’m looking to make the choke three and a half turns 18 mh core you say sounds simple,
But I cant seem to get hold of one in England, It looks to me like you have used two E s rather than an E and a I ??,  (any help please).
You said running at 8 kW the amps would be about 300 amps is the 8000 LF that good, sounds low to me,
My experience with a modified sine wave unit it would be 700 to 800 amps.
I like the idea of being able to read the battery amps, can this be done without butchering the unit to much, any help would be great.
Any ideas or mods running 8000 w LF with a 3650 w PV system grid tie.
Fab thread very interesting. Best to all. Steve.