Author Topic: Power Jack LF 5000W Inverter Board Swap  (Read 4424 times)

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Offline OTG

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Power Jack LF 5000W Inverter Board Swap
« on: August 30, 2015, 09:11:23 PM »
Hello All,

As noted in Oztules EPIC "guess who bought a power jack inverter" thread, my Mainboard popped a bunch of mosfets and I'm now installing replacement Main/Control boards. I've hit a few bumps however, which I've asked the supplier about per the below 4 points and corresponding images.

If anyone out there in anotherpower land can share their own advice/experiences on these points or board swaps in general that would be greatly appreciated!

Also, a few notes that might help others...
- If you had old boards (i.e. LW-CONTROL-REV 1 and LFPSW-MAIN-BOARD REV:1.4) and are replacing them with new ones (i.e. V2.2/V2.2a boards) you will need to drill new mount points into the aluminum chassis as they don't align with the old boards mounts.

- You'll also want; a good scalpel/hobby knife set to cut all that horrible red glue off the various sockets/plugs; and a hot glue gun for reattaching the Bty Volt/ LED board to the chassis front panel (a pain I know... screw mounts would have been much simpler!  ::) ).

- Interesting to note the old Mainboard had 3 Caps (18000uF-50v) whereas the new board had 4...  ???

- Finally, when I removed the end panel containing the battery teriminals/cooling fan, I found burn marks on the bottom screws/aluminum chassis!!!  :o  It appears to have had a short across the terminals/through the chassis at some stage. Could that have been the root cause of my fet-pops? Any ideas on how best to prevent this in future (strips of electrical tape on the chassis, cover the bottom terminals in some non-conductive coating)?

ila_rendered

1. I can see the Thermistor/Thermostat transformer connections on the new control board, however there a third connection thats soldered to the middle of the board with an eye terminal on the end of it (per the ? ? ?) . This wasn't on the old control board and it's not obvious what it's for. Can you advise what this is for and where it's to be connected to?

2. Per the photo's the old Thermistor/Thermostat wires were soldiered directly to the control board and then held with a hot glue gun. Then they were stuck to the transformer with a black glue/resin. Also the wires on the new Thermistor/Thermostat are too short to actually reach the transformer. How would your engineer recommend I make this connection?

My thought is the easiest way would be to use the existing Thermistor/Thermostat glued to the Tranny, cut the wires connecting them to the old Control Board, then crimp these wires to a new set of the small white 2 pin plugs used on the new boards. Then I can simply plug them in.

Does your engineer see any issue with using the existing Thermistor/Thermostat in this approach and/or would he recommend another approach? Also can you tell me what those small white 2 pin plugs are called so I can order some off e-bay, or could you ship me a new pair?

3. My final hurdle is with the cables connecting the terminals. The new Mainboard has 4 x strands of 8AWG power cable
soldered to the board and then paired off and crimped into 2 x eye terminals for screwing down to the 2 x negative (-) battery terminals. The same existing positive (+) power cables however are 10AWG. This mismatch could obviously pose issues. Can you ship me a new pair of 8AWG positive power cables?

4. I also note that the two cable bundles coming out of the transformer each consist of 3 x strands of 10AWG power cable. One yellow the other black. Can you engineer advise if there will be any issues here considering the new Mainboard's use of 8AWG cable for the battery terminals? Any advise appreciated.

ila_renderedila_renderedila_renderedila_renderedila_rendered

Thanks all!!!  ;D

Offline oztules

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Re: Power Jack LF 5000W Inverter Board Swap
« Reply #1 on: August 31, 2015, 05:20:39 AM »
Can't help with board swaps specifically, as i don't use the carcass.... nor the trnasformers, nor the cooling system..... hmmm... so we will try to answer some of your questions

My latest card is only the 1.4, the older ones are 1.2.
The fan systems have changed, but with the 5000w I assume only 1 fan,,, so extend the leads that don't get to your transformer... cut and join old onto new... very surprised the new ones can't make it to the front of the board to the tranny.... but...

1. Eye terminal to neg batt post... No .. no-one really knows what it does, we think it stops the over voltage shut down when using pwm solar chargers... but don't know for sure...... EDIT: just saw Seans post, PJ use a 1m across R14 to stop this o/voltage problem... so what does it do????now I have no idea.

2. Cut and extend if they don't get to the front of the transformer at least.

3. The wire size won't negatively effect you. They are only 6 inches long, so voltage drop will be insignficant. In free air those four wires can carry 200 amps combined, and with the fan... more. You only need 100 amps-120 for shorter periods. The unit won't do 3kw for too long without transformer being better cooled or upgraded. My 8kw boards use the same wire.

4. Can't see a problem here, as the fets control the current ...not wire size. There could be more wires or bigger, but i don't think it would alter the performance any.

The splatter marks look to be made from the caps discharging, as a battery short across there would destroy the bolt heads, and dig a very decent hole in the Al.
Do you have corrosponding marks on the terminal bolts?
From memory they are much higher than the floor, which means floating material inside or more likely, back plate removed before discharging capacitors at some time in the past ( factory ???testing... ????)

Doubtful they contributed to the demise, but check everything around there... were they loose, anything to suggest it happened in your posession? etc.

I would expect that kind of short would just result in a restart ( under voltage lock out )... but you can never really know.... but check your terminals anyway to see.

Perhaps others using the powerjack body can help out more.


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

Offline OTG

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Re: Power Jack LF 5000W Inverter Board Swap
« Reply #2 on: August 31, 2015, 07:14:40 PM »
Thanks as always Oz - you're a bloody electrickery legend!

Per point 1. I guess some things are just meant to remain a mystery...  :P Thanks on points 3 and 4 too!

Yes only 1 fan for 5000w, it reaches the Control Board fine. But the new Thermosat/Thermistor wires are too short to reach up-round where they are currently glued on the tranny. So yes I'll need to cut and extend both.

New Questions
a. Would you use the existing Thermosat/Thermistors that are glued to the tranny, or do you remove/replace them with the new ones (and if so how?)?
b. Also does polarity matter for either of these wires? I can figure out the thermistor, but you'll see the old/new thermostats are wired differently (Old - Red to left pin, White to right pin; New - Red to right pin, Black to left pin).
c. One final conundrum... per below, the old (with glue all over it) and new Battery Voltage dial's are set differently - The Old one has the notch aligning up to 1 and 6. The new board has it pointing to 3 and 8. So... does it matter? Should I change the new one or leave it? Any guidance most welcome!

ila_rendered

Otherwise yes Oz, those splatter marks were directly beneath the bottom + - terminal screws and both screws had corresponding burn marks. Everything inside the inverter was secured super tight, and this is my first time inside of it (long after it died/caps discharged), so I expect this will remain another great mystery of the universe!  :P

When my 8000w units arrive I'll definitely be double checking the innards before use. 

Offline oztules

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Re: Power Jack LF 5000W Inverter Board Swap
« Reply #3 on: August 31, 2015, 07:46:44 PM »

a. Use the new ones in case they are different temp/resistance thermistors.... originals were 10k@25c.....
 temp switch is solid state, so it will pay to keep the wiring consistent with the manufacturer.

b. keep to the new scheme from plug to device as original..... so that they can't say that you didn't.

c. read yourbooklet, it will tell you which settings are for what batteries... set it to zero for no charge or the other numbers for differing battery technologies. It is only the set point switch for the battery charger routines. As I don't use the charger, I don't recall which number is for what.


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

Offline OTG

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Re: Power Jack LF 5000W Inverter Board Swap
« Reply #4 on: September 01, 2015, 04:41:26 AM »
Ok, ta.

I assume it's just that black resin'y kinda' stuff that's holding them both to the tranny? Should I just use a hobby knife to cut the existing ones free, then just slot the new ones into the same place? Should I then also glue (would a standard hot glue gun be ok, or does it have to be that black stuff for thermal reasons or something?) or maybe just tape them down?

I dont use the bty charger either so I'll prob just leave that bit alone.

Offline oztules

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Re: Power Jack LF 5000W Inverter Board Swap
« Reply #5 on: September 01, 2015, 05:05:48 AM »
The temp rate of change is pretty slow, so even hot glue would probably do ok.... it is fairly non conductive, but the rate of change will probably allow it to work fine... provided it does not remelt.....

or......  perhaps loosen the top nut, and push them under the rubber a bit, and retighten and that way they are physically held too the transformer body.

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

Offline OTG

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Re: Power Jack LF 5000W Inverter Board Swap
« Reply #6 on: September 01, 2015, 04:14:46 PM »
Gotcha, thanks OZ.

I'll give it a crack and will update the thread with results.

Offline lighthunter

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Re: Power Jack LF 5000W Inverter Board Swap
« Reply #7 on: February 08, 2016, 01:07:32 PM »
Hello! I have an LF6000 in use, it works ok but sometimes has a sharp cackling noise (60hz) coming from transformers. When this problem first occured i had found pressing on the opto chips would make the sound go away. I have since replaced optos and solderd directly to control board. The problem isnt anywhere near as bad as it has been... when it is really bad the dc ammeter flickers wildly when it gets in a spell. the problem isnt completely gone though, it fades with some loads, others its louder. The grid tie connected to it will sense it and drop offline which happens at least a couple times a day.

Nothing has catostopically failed or burned on this unit, all original except for optos. I took control board out today and removed masking tape on bottom (why on earth would they???) I also scrubbed board with alcohol and toothbrush then removed opto sockets and soldered on board. Not even a bit of improvment

This inverter did go through a battery charging episode. It tripped the breaker feeding it that was thethe last time i ever used the charge feature. Could this problem be something on the main board like wounded fets or bad caps? Resistors??? Anyone else have this problem???? I have another cmplete unit identical to this one and i would swap parts but that one has same problem only worse, last i used it, it would start up normal and run moderate loads until it warmed up and then look out. The sound would start becoming audible then amp meter starts flickering and it created enough havoc merely connected to battey bank to make noise through other pj running loads and grid tie and kick it offline. System all works well except for that. Sometimes you wish it would just explode so u know what is ailing it
LH

Offline dochubert

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Re: Power Jack LF 5000W Inverter Board Swap
« Reply #8 on: February 26, 2016, 04:08:54 PM »
 Hello lighthunter,
You definitely have a puzzling problem.

If both units do the same stunts, what common sense I have left tells me its not in the units themselves but in something common to both.  That leaves batteries, charging system?, the connected grid tie inverter, and ac loads.

Have you run the powerjack without the grid tie connected and still had the problem?


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Offline lighthunter

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Re: Power Jack LF 5000W Inverter Board Swap
« Reply #9 on: February 29, 2016, 06:57:38 PM »
Hi dochubert, thanks for your ideas. In fact shortly after i posted, i thought the same thing. Heres an update... "have you run inverters without gti?" Yes, one of them runs perfect no sounds, no issues. I then proved noise in xfmr was coming from GTI. Its a hf transformerless 3.5kw unit. The sound comes and goes depending on loads tied between them. When PJ is putting gti pwr in batteries its loud. The gti must be using pretty hard switching. Its all normal i just misread it. The other inverter defenitely has a problem. It hasnt blown up yet but cant b used either. Cold startup result in loud rattle of xfmr. If try starting enough times it will run and idle current declines to fairly normal 1-2 amps. If you preheat large heatsink connected to positive with hairdryer, it will start and run fairly normal. I ordered new 4110 fets like Oztules had suggested, hope that does the trick.

The grid tie and the good pj run fine every day for the most part but i do have trouble when the GTI output and AC loads are too close to equal...the pj fet current goes to nearly zero and within a short bit the gti will go offline. I suppose if i had more than one gti then that would never happen. As it is the solar output and loads in use always match at some point each day. I will have to put a bit more into the control program to avoid that condition. Be interesting to know if anyone else has that problem with a single gti/pj pair. Come to think of it, is anyone else besides Oztules pairing a pj with grid tie? I think he uses more than one gti so that problem may not exist.

Cheers, Lighthunter
LH

Offline dochubert

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Re: Power Jack LF 5000W Inverter Board Swap
« Reply #10 on: February 29, 2016, 11:36:27 PM »
Maybe a dump load or two set to kick in just before things equalize?  Keep it off balance

I hope you keep us up on your progress. I hope to try the gti/pj setup when I get to my off grid location and am very interested in how yours works out.  I've got a xantrex gt3.0 gti  I plan to use for that.  It has large transformers and has been working as a normal gti for me for more than ten years now, so have high hopes for it paired to my pj.

Btw, how is your solution for raising the ac output voltage holding up? (something else I'm very interested in)  Any chance that mod is contributing to the other problem?  Just a thought ( and hope its not)

cheers

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Offline lighthunter

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Re: Power Jack LF 5000W Inverter Board Swap
« Reply #11 on: March 02, 2016, 08:01:57 PM »
Hi again :) I will keep you up on progress, its awesome there are others who like this kinda stuff. My wife is the artist type and really has that blank look whenever anything with numbers or electricity is mentioned but she is an awesome painter..does that 5 min painting stuff with aerosol cans like on u tube.  Anyway, the pairing of a grid tie with another inverter is way more fun than a single inv and battery charge control, its almost like an engine, has some fun challenges too!
Good idea on the dump load to offbalance.

I ditched my first pj voltage mod and put things back to original. What im using now seems to be flawless. A pic will follow post to help describe it. My voltage needs were to match a gti of 240/120 60hz with the 6000lf single phase 112vac. The gti monitors phase to neutral on each side as well as the phase to phase. Those parameters were vph130 vpl107 vh266 vl177 it also watches for rate of voltage change.

I removed cover from pj and removed toroid, then removed bat leads from 2 of the bat terminals and connected those two (now unused) terminals to where the toroid primary used to connect. The PJ box is empty except for the boards and fans. Some time ago i had snagged a powertronix 3kw medical toroid with ratings... sec 37v pri 235v @12.5A. So after carefully checking phase relationships with a meter (light bulb works too) i paralleled the high current windings together onto the pj hbridge terminals now on the end of the inverter. The secondaries were then wired in series.  One of the secondary leads were also connected back into the pj box through another canibalized terminal in front. (the white plastic terminals) keeping all original xfmr phase relationships, connect the one lead back to maintx (the one that didnt have current sensor). The other lead gets bolted together and heatshrinked with all of its original wires but not to the boardl anymore. This way the board can still monitor current but not voltage. Then I found an efficient 20lb transformer with many secondaries and a240v primary, plugged it into grid mains 240v and probed and seriesed secondaries till i got 112v. This procedure will verify your output regulation voltage before you even hook it up :) next (observing phase relationship) tie this 240v primary to the 240v output of the two toroids, then bring the 112v leads back to the pj cntrl board on maintx L and maintx N.
Turn on and test, if all is correct, connect the grid tie to the 240v output of series toroids and connect any 120v loads to the original outlet plugs. ( i used 112v because thats what my pj regulated at originally. Before making the modification, its helpful to measure the toroid primary while idling. Mine was 17vAC (use Trms meter). After the modification the primaries(now two) measured 18vac. This is caused by the control board having to run the primary harder to get the 112v back that it needs to be in balance, the significance of this is now your batteries have one less volt of headroom for voltage sag. There are 3 ways to correct this, stay away from heavy loads, add a few turns to the secondaries of each transformer, or order LiFePo4 batteries. I have been avoiding long term heavy loads and recently ordered lithium iron bats, i havent received them yet.

This PJ is now very solid 117/239 VAC split phase under 2kw load, the two toroids are almost identical primary and secondary voltages open circuit. That wouldnt be necessary but it makes things simpler. one nice thing about this circuit is that when the GTI is pushing high power into the secondaries, at 240 and you have loads connected to the 117v (only one of the toroids) the other unloaded toroid passes its magnetic current to its primary looping to the loaded toroid primary without having to go through the pj fets.

I hope this isnt too hard to follow, feel free to ask for clarification.

Lighthunter
LH

Offline lighthunter

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Re: Power Jack LF 5000W Inverter Board Swap
« Reply #12 on: March 02, 2016, 08:17:14 PM »
That pic is horrible, oh well its good simulator software but i cant edit with text. So the two xfmrs in a pair are the two 3kw toroids in series sec parallel primary. The v source on the left is a gti inverter with a series resistor mostly to force the auto trace routing to make a square corner. The xfmr on the far left is the voltage mod xfmr that samples the full 240 and feeds back 112 to the PJ control board represented by the ctr ic. The h-bridge is representative of the pj main board or fet board.

Hope everyone is having fun,

Lighthunter
LH

Offline dochubert

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Re: Power Jack LF 5000W Inverter Board Swap
« Reply #13 on: March 03, 2016, 12:14:58 AM »
All I can say is Wow!  Very impressive!  I'm a bit slow, but I've read your description 3 times (so far) and am starting to get a glimmering.  I'll keep at it until that lightbulb over my head blinks on.  I actually have quite a few years of electrical and electronics experience, but you and the other guys on this site make me feel like 12 years old with my first multimeter looking for things to measure.  I'm hoping to ride some coattails here long enough to learn enough not to blow myself or my house up building my power system. 
Got a good chuckle reading about your wife's blank look. Could have sworn you were describing my wife.  She has that same look when I get excited and start telling her about my latest project.

I'm looking forward to your next update.  It may be too soon to ask but wondering how you control the system when your batteries are full.
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Offline ClockmanFrance

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Re: Power Jack LF 5000W Inverter Board Swap
« Reply #14 on: March 03, 2016, 02:55:23 AM »
"Be interesting to know if anyone else has that problem with a single gti/pj pair. Come to think of it, is anyone else besides Oztules pairing a pj with grid tie? I think he uses more than one gti so that problem may not exist."


Hi Lighthunter,

Yes, I am running GTI's with PV with my 6kW OzInverter, with the 15kW PJ Boards.

I have 5 SMA SB's, not all installed yet, the low frequency types that are heavy, some are used some our new but old stock. They are cheap as chips as they are small, ie below or at 3kW.

What I have found is as Oz has said, the GTI back feeds to the batteries with out any problems. I also have 5kw of PV DC direct charging through Midnite Classic and Tristar controllers. If the batteries are full the DC controllers back the PV off, but then the AC output voltage of the OzInverter starts to climb, I can shut down the GTI's and their PV if no loads are on, by adjusting the GTI shut down voltage.

The GTIā€¦.. Most come ready set up with the appropriate Country code settings, now with the United Kingdom this code is G83/1.1 this means that the GTI normally at 230vac 50HZ and will only work within a set  AC Grid range of 207vac to 262vac however the SMA Sunny boys are normally set to automatically disconnect at about 247vac. So in general your GTI will shut down anyway if the mini grid it is connected too rises to 250vac. However, the process of the GTI re-starting itself may take several minutes.

Oz reckons that the GTI's can backfeed through the OZInverter at about 8kW, but heck that's a lot of raw power going into the batteries, so hence me using small GTI installations so I can adjust each for different voltage shut downs.

In essence I can now balance the loads being used against the GTI's output with out thrashing the 1300ah C10 48v batteries, and allow the 5kW of DC coupled Controllers to fine tune the batts.

However, if you are using standard torroids then there may be other limiting factors at play. With the OzInverter we wind the toroid to achieve the best and robust functions.

I trust this helps.