Author Topic: guess who bought a power jack inverter  (Read 196465 times)

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Offline oztules

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Re: guess who bought a power jack inverter
« Reply #30 on: July 26, 2014, 01:25:59 pm »
e core close to you... http://www.ebay.com.au/itm/E6527-Kaschke-E65-E-EE-Ferrite-Cores-High-Frequen-Power-transformer-AL-7900-1set-/370597734866?pt=LH_DefaultDomain_0&hash=item564958a9d2

These units are pretty efficient... 800 amps would be only 30% efficient, and need to loose 14kw as heat...... does not sound right unless you are talking 12v units.

Battery amps are best read with a 300 amp current shunt and digital or analogue meter. You don't need to mess with the unit itself if you don't want.

You need the ecore and the unit to run the grid tie... nothing more.... but you would have to limit your solar to maybe 2800 or so watts  to keep the temp down in the inverter....... and some way of turning off the grid tie when full, or a big dump load... or if your an animal, just let the batteries over voltage and the power jack will shut down anyway.

To go further you need more transformer core or better cooling. Grid tie is high power for long periods, that you would normally never see in off grid standard uses. Pulling multi kilowatt loads for 10-14 hrs at a time would be harsh on the batteries in off grid life..... more usually 500w/ hour  on average.

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

Offline lighthunter

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Re: guess who bought a power jack inverter
« Reply #31 on: July 26, 2014, 04:54:45 pm »
 :) Hi please dont let me interrupt ur conversation, i just hav a quik question for Oztules, do you kno how to adj. Ac output voltage on pwrjk inverter? I just got my2200w solar running, works great but i hav a 76 meter power cable run and my pwrjk regulates at 110v would like to bump up to 115 or 120. right now i can sag 3 to 4 volts over 2kw. Thank You
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Offline oztules

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Re: guess who bought a power jack inverter
« Reply #32 on: July 26, 2014, 05:57:00 pm »
No I have not looked at the acv regulation... may soon.

Are you using HV solar and a grid tie on this unit, or LV into batteries near the array... if using HV and grid tie, take the PJ back to the house, and transmit the 400VDC from the array, and lower the losses that way.

Please interrupt and describe your system, and post pics too if you could..... do a story etc..... more the merrier.


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

Offline lighthunter

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Re: guess who bought a power jack inverter
« Reply #33 on: July 27, 2014, 06:28:53 am »
 :) OK you talked me into it!  Both, to post my project and to move the inverter to the house!
Actually i started to do information post yesterday but got interupted. It may b a bit before i get it posted and ive never posted a pic b4 so hav to figure that out.

In ans to your question, im using low voltage not grid tied batteries at panel yet i love ur idea of moving inverter to house so it isnt exposed to moisture, temp xtremes etc.

Since you posted idea to run HV for long cable run i havent been able to sleep thinking about how to downconvert 270v to 29 at 95% efficiency without spending 1500 on a xantrex. There are 2 reasons i did the low voltage at panel. I foolishly bought 2 different types of panels and i wanted to omit expense of fancy charge controller. Since panels are different 5pnls max pwr current of 8.84A while the other 5 are mpI 8.4A. If i series connect these i loose .4A x 5 panels at mpv 22 v is just about 50 watts. Not a terrible sacrifice to get inverter inside. Or i could do 2 separate series strings. One at mpv 22v x 5= 110v and the other mpv 30v x 5 =149v. Since you mentioned this i have been thinking about modifying and paralleling several LED power supplies. I think they would down convert 150DC to 29 nicely if i feed high v dc onto board at high v caps, then modify volt regulation to match ideal mppt of panels, a bit difficult but possible yet im not impressed with efficiency of those pwr supplies i think they run at about 85%.

B4 i plunge into another sinkhole of time investment and fix something that isnt broke i cant forget this setup has been working beautifully for a week now with no adjustments,maintenance or tweaking and just passed the 60kwh mark. I have it set up to add and shed loads. Its been running 2 freezers and 2 fridges pretty much constant every day and when it has extra it runs a 6kbtu ac unit or the 650w water distiller. When i come home from work often there is a full gallon of distilled water in it.

If u know of a circuit that can downconvert at high eff letme know. I think 150 to 29 exceeds abilities of common buck circuit doesnt it?  I will post more on layout of project soon hopefully today! Gotta go do yard work at the moment.
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Offline oztules

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Re: guess who bought a power jack inverter
« Reply #34 on: July 28, 2014, 05:00:22 am »
If it is working well, I would not be in a rush to change it. There is no right way or wrong way, as all the theory has to be couched in the practical circumstances... or horses for courses...... 3 or 4 volts is not problematic

Remember, in your current setup, the watts being transported the 70 meters is probably  lower for the AC than the DC..... ie your average power used up by the fridges and freezer will be in lower quantities than the 2kw you will  be bulking during a daylight period... well it has to be, as your daylight does not last 24hrs, so at least less than half on the drain side as the charge side.... just my guess, so any improvement will have to be decent to be worth while...... or if you use power in high shorter bursts, then the opposite may be true.

A big buck converter is the DC transformer you seek, and i don't have any circuits on bucks.... have only built boost.

In this country, galvanically isolated big grid ties are cheap as chips, and would have solved your problem for peanuts, and happy to 450vdc.

If your a bit of a ratbag, you could buy the  PJack 240v or 220v 60hz control card, series the transformer outputs, and transmit 240vac and use a big transformer... probably from a big welder with split phase transformers that you folks  have over there, and bring it back to 110v.

If your even more of a ratbag, you can just series the transformer outputs, and let the unit sample only one of them for it's 110v, but you can use the 220v as your AC drive to a step down transformer....... ac coupling will need to  be carefully polarised or damage will occur... you will also have doubled the power output so beware..

You may not want the batteries at the house either.... everyones situation is different, and every voltage conversion costs a bit of power too.

"650w water distiller. When i come home from work often there is a full gallon of distilled water in it. "
I have built a solar powered reverse osmosis unit... runs on about 90 watts, and produces over 800 liters of water/day  @1ppm in summer, and 400 liters in winter.... seems a better way to make pure water.... and stills should be used to make other things... hic....hic


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

EDIT: Noticed from your older posts, you have only 1 transformer to play with... oh well, the idea was there.


Flinders Island...... Australia

Offline lanyho

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Re: guess who bought a power jack inverter
« Reply #35 on: July 28, 2014, 06:39:12 am »
Hi friend, I bought the inverter LF-5000-24-220, works perfectly.
But I have a little problem with overvoltage protection. When my epsolar 3215 recharges the battery, voltage rises to 29V (checked with a multimeter). My PowerJack but triggers alarm with overvoltage protection. It should start alarm up to 31-32V. You advise me how to easily fix alarm to 31V? Thanks

Offline lighthunter

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Re: guess who bought a power jack inverter
« Reply #36 on: July 28, 2014, 02:42:30 pm »
I had a very similar problem a week ago. I could not figure out where the high voltage was coming from . Finally i caught it in the act, it was my charge controller doing an automatic battery maintenance/ equalize charge on a schedule. Bumped my voltage to 32. The powerjack will lock out when it sees this. Check your charge controller settings and manual.
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Offline oztules

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Re: guess who bought a power jack inverter
« Reply #37 on: July 28, 2014, 03:17:22 pm »
Yes it seems the inverter is very susceptible to current spikes.

If you have a pwm charger, then you will probably get a lot of this nonsense. I have tried to understand why the batteries are not capable of squashing the current spikes from the PWM of the controller.... but maybe 70 amp pulses originating at 72v is hard to squash.

The multimeter does not show it, but the CRO does..... and the inverter is looking at the peaks.... drat...

It will happen in the absorb/finishing state, as that is when you start to PWM... before that the fets are switched on fully ( so no spikes here), but it is when it throttles back near end of charge this quirk starts to inflict it's problems on us.... and what you see on your dvm is not what the chip sees... it sees the pulses.

I decided I did not ever want the inverter telling me when it wants to switch off from high voltage in the bank.... turning off won't help the battery...

So I put  4V zener across the resistor near the chip that says "cut if high"...... now it will not ever turn off from OV just like I like it.

If there is any turning off to do.... I'll do it....... not it.


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

Offline lanyho

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Re: guess who bought a power jack inverter
« Reply #38 on: July 28, 2014, 05:22:25 pm »
Yes, this is a problem in finishing charging. Epsolar 3215 is a MPPT controller. Voltage pulses are a good idea. It might help a large capacitor at the output of the controller.

oztules: please do foto zener diodes, if possible.

Thanks

Offline lighthunter

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Re: guess who bought a power jack inverter
« Reply #39 on: July 29, 2014, 12:18:30 am »
Hi Again! :)  Thanks for overvoltage info. Great ideas on power transport. I did snag another 6K inverter identical to the one I already have. Do you think it would help to remind them  I need both transformers this time? If not I'm happy anyway, from what I've seen so far this unit has been a workhorse. It runs mostly at 800 to 1200 but sometimes I see it at 1945 continuous and 2200 on load starts. It will get a 48 volt board eventually and 2 transformers to make it a true 6K unit.  Yes, thankyou, watch phasing (polarity) when connecting transformers.

Like you said, improving efficiency of this setup may not be that easy to do but I love the idea of only panels outside.

"Galvanically isolated big grid ties" ??   Are you talking about a voltage boost on each panel into a commo 450v buss all connected to 1 larger grid tie inverter?  The small grid tie inverters on each panel didn't appeal to me because I want ability to run without grid if I want to. I remember you mentioned something about several single panel grid tie inverters all running into your pj acting as grid. That sounds neat however the small grid tie inv are not pure sine are they?  Maybe they are, Ive never looked at them much.



"stills should be used to make other things" He He ;D yeah, I doubt water was the first use for a still. It does beat buying
it at $1.20/3.8liter. Unless of course you are a genius and you can make anything ;)

Great idea on RO unit I might like to try it sometime. Right now before I try to describe project what do you think about
series connecting all panels, send to house at 270v dc. Purchase a 5KW VFD and wind a ferrite core with 3 primaries and a secondary, vary frequency of VFD to match MPPT and rectify output to batteries.   A home built buck circuit wouldnt be difficult either.

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Offline lanyho

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Re: guess who bought a power jack inverter
« Reply #40 on: July 29, 2014, 06:27:18 am »
oztules: you should  this resistance over the mind?

3101-0

Offline oztules

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Re: guess who bought a power jack inverter
« Reply #41 on: July 29, 2014, 03:02:40 pm »
Yes Lanho.... thats the one.

It will stop the thing ever stopping from over voltage.... thats the pro...

The con is that your charger has no longer any idea of when to give up and move out of bulk charge, as it can't judge the SOC at the high end of the charge.

If you take more interest in this part of it, then time spent getting the right zenner combination  may give the best of both worlds.

I don't use the charging  except for rare occasions.


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

Offline oztules

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Re: guess who bought a power jack inverter
« Reply #42 on: July 29, 2014, 03:19:53 pm »
Lighthunter,

No I use AS4777 approved inverters as found on normal 400vdc home solar installs.
The box i built the inverter in is from one of them ( they were 1.5kw inspires from CEHE tech in China. beautifully built too.... but best of all have huge 3kw torroid cores in them, which we rewire to our specs..... these are not single panel inverters as they take up to 150 - 450Vdc for the input, and can do 1.7kw each output.
Here they are again:

This gives you some idea of the size of these things.
3103-0


once again with the internals on the prototype ( so cheap you just keep making a few spares... have 4 now)
3104-1


For those interested, here is the screen shot on the scope of the wave form of the input to the transformer secondary from the low switch fets. ... don't panic it comes out the other end as a pure sine wave @ 240vac 50hz... no they are NOT square waves, but a pattern of very very close individual pulse waves of varying widths, that look to us like a square wave unless you magnify it up, then you can see each pulse width making up the "square looking wave"... they are as they are supposed to be for pure sine operation.
3105-2

This is the effect of a slightly larger choke on that same input wave. The curved short waves are actually the tops and bottoms of the  fine pulse width waves from before,
3106-3

How that small of inductance makes that big a change is difficult to understand......, and when you see the output.... is is a pure sine wave with no distortion.... amazing really...

That transformer is a little one from a name brand 1.5kw Australian inverter that failed, it has more primary turns than original, as it was 24v, but mocked up to be 48v .

The neighbor runs a power jack ( heavily transformered, current bypassed for 6kw cont and zenner over the resistor etc. It now is the frontline inverter for his house, as it performs better in all aspects than his near $10,000 selectronic.......it has been relegated to standby duty... and to start the genny if needed.....

His PJ takes two big grid tie inverters on it's output from remotely placed solar panels .. one normal setup  on the power shed with mppt controller, a few kilowatts on the house with grid tie unit and another few kilowatts on the main barn with grid tie unit... about 70 meters spacing I guess.

These things are not toys, they are serious contenders



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

Offline lighthunter

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Re: guess who bought a power jack inverter
« Reply #43 on: July 29, 2014, 07:45:00 pm »
Oztules, and anyone interested here is the good bad and ugly of my solar.

The panel ... 2250W, well 2050 to be exact, its missing one 200w panel.
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Offline lighthunter

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Re: guess who bought a power jack inverter
« Reply #44 on: July 29, 2014, 09:28:57 pm »
Ok, the pics are sent, as you can see, I have no idea how to put the text between them so here it is.

The panel is self explanatory for the most part. Its a prototype as of yet.  This arrangement holds it solid for now
but there will be pillow block bearings under each side in the center allowing panel to sweep 30 degrees each direction
from straight up with bearings attached to v shaped end frames.

The next pic, is the back of panel where a (trakmax 40) runs 4 200watt panels as a stand alone charge controller connected to 2 105AH 12v batteries. (24v system). There are 3 dpdt relays beside the charge controller that connect
the remaining 5 panels to the batteries.  These have mpv of 29.8V.

Guardian transfer switch has been modified with 6 DPDT relays serving as active transfer switches steering grid
power or inverter power to each of 6 load groups. The main controller for the panel is an Idec programmable relay with
1 expansion module which switches all 9 relays and the inverter on/off when needed.

There is a picture of the program....
And a picture of the power jack inverter display as its running happily.

And the pic of the circuit board is a gem I just received that will boost or buck automatically at efficiencies of 95 to 98.5%...it is needed to hang the remaining panel as that panel is 22vmp, useless to charge 24v bat without boosting.

How, it works.... At 7AM a clock in the idec relay switches the 5 large panels to the batteries and turns on the inverter. It monitors battery voltage, when the voltage reaches 28v, the first load switches on. If anything is connected to that load group the battery voltage drops as the inverter uses some of the power. As the sun gets stronger and output increases, the voltage again climbs to 28 indexing the count to turn on load #2. and so on all the way to #6 . If after the first load turned on and the voltage did not drop it would simply index to number 2.   If a cloud comes along there is another threshold
trigger that will index the count down and shed a load in sequence. At 5.30 PM the loads all shut off transferring to utility and the inverter shuts off while the panels remain connected to recharge the battery fully for the night. At 10 pm the panels are then disconnected from the batterys.

Lately it has been running without any problems at all, clouds or sun. It runs at about 400watts with heavy cloud cover.
There are always little things that you notice for improvements as you observe a machine running, one of those is I want to add a state of charge meter to the system, either program one into the relay or maybe add one someone else has built.  It is difficult if not impossible to accurately detect state of charge on voltage alone during changing loads and charge conditions through the day.  It does real well but I have caught it running the battery in a 25% SOC in heavy clouds. At that point, i did increase the lower threshold a bit so it would shed loads earlier and separated the loads some so they shed at different lower thresholds instead of all using the same point. This appears to be working great but I know if I want the batteries to last 5 years I better make sure they dont deep cycle too much.

This is all in the testing phase of the project.  The panels will need to be moved once the tracking pivot is done and the sun angle makes it necessary.


 
Health Warning: May contain traces of nut!
LH