Author Topic: Output voltage adjustment  (Read 4645 times)

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Offline dochubert

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Re: Output voltage adjustment
« Reply #15 on: April 25, 2016, 10:20:55 AM »
Thanks for the info lighthunter.  I will test for secondary polarity as you said before next full test.  It didn't matter when both maint wire sets were floated, but with the one side still connected, resulting in a primary and secondary lead (of new transformer) connected to same point electrically, it will matter.  My theory at this point in the experiment  is that the maint N conn has to remain connected as original or you lose the feedback loop.  Can't float em both.  That was the main difference between my hookup and yours, besides the step up 115-230 transformer instead of a straight one to one 230-230 model.   With secondary turns removed, its now a 115-222 transformer, which is likely still a bit high.  When I see what it does to output I will probably take off a few more turns to get 115-220.  The goal is powerjack output of 120/240 at no load or light load
Eventually will replace the 115-230 transformer with a 230-230 model anyway so that primary connections can hook directly to the maint leads.  Neater and don't have to worry about the ratios because of the step up.  Also want to get one small enough physically to tuck into the case and still be able to close the lid for proper airflow.  I'm looking at a 50 watt model that is small but should be enough power handling to do the job here.
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Offline dochubert

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Re: Output voltage adjustment
« Reply #16 on: April 25, 2016, 11:44:46 AM »
Getting old really sucks sometimes.  For any close up work or looking at really small stuff I now need strong reading glasses.  Even with glasses I get small writing wrong sometimes and it leads to me doing something wrong or just backwards.  In this case my thinking was backwards as I misread the maint N and maint L connections points.  Maint L is L1 and maint N is L2 actually and not the other way around as I stated in an earlier post.  Also I have been referring to maint L as maint X.  Poor eyesight again.
All this is leading up to my mis-connecting the polarity test and likely frying my transformer. Fried the wire anyway.  Powerjack is undamaged, luckily.
I will be waiting for a 230-230 transformer before any more experimenting with this as the step up version is just too likely to be part of the problem.
Now that I have thoroughly confused the issue, lighthunter which connection did you float?  maint N or maint L?
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Offline lighthunter

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Re: Output voltage adjustment
« Reply #17 on: April 25, 2016, 04:05:03 PM »
Quote
"which connection did you float? maint N or maint L?"   

(MaintL)

So the 120/240 split phase Pj samples the 220 i take it?!..

The nice thing about connecting 3 leads of the new transformer while.
Leaving the pj all original is you get to fine tune it all and make sure it works before.
you actually make the change.  In other words the add on transformer is powered
by pj output of your choice 120 or 240 , the output winding can then be meaaured with voltmeter and compared with maintxn and maintxL. the new transformer then should ideally measure only a few volts less than the maintx leads and yes in phase.

Then you can make the changes to the pj circuit. Too much at risk to do it any other way. They are tough though. I'm still on the original fets in both of mine.

Hang in there it will work out perfect!

LH
LH

Offline dochubert

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Re: Output voltage adjustment
« Reply #18 on: April 25, 2016, 08:00:32 PM »
Yes, my control board is 230v, so voltage measured across maint L to N is around 230vac.  Ordered an isolation 1 to 1,  230v-230v transformer yesterday so will be waiting for that to arrive.  Still bothers me that we're connecting the transformer primary to the still connected maint N and the floated maint L wires, then connecting one secondary lead to the same point we just connected a primary lead to, the still connected maint N and the other secondary lead to the now vacant maint L terminal.  Shorting primary to secondary, at least on one leg.  I realize its working for you or I wouldn't even consider doing that. 
Prior to that, for polarity testing, without floating the maint L leads, same connections except leave secondary lead that would have connected to maint L terminal open, not connected to anything. 
Measure from open lead to Maint L.  If small voltage then polarity is correct, if large voltage, reverse secondary connections and retry.
When verified correct polarity and proper secondary voltage reduction, go to hookup as above for full output test.
Does that all sound correct?
After today's smoke test I have to admit  I'm a bit apprehensive.  I don't mind too much frying a relatively inexpensive transformer or 2 but would hate to do damage to the powerjack.  A good thing they're pretty tough.
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Offline lighthunter

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Re: Output voltage adjustment
« Reply #19 on: April 26, 2016, 04:13:13 AM »
I'll try to post a drawing, I agree,  Somehow the commu ication on what wires to hook where is not working out.

LH
LH

Offline dochubert

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Re: Output voltage adjustment
« Reply #20 on: April 26, 2016, 11:46:23 AM »
Thanks for all your trouble.  I'm sure the problem is with me.  Sometimes things don't sink in quite right, but a schematic always helps.

Btw, the little extra board bolted onto the corner of the control board is for the powerjack power meter and has a red lead and black lead, with red hooked to maint L and black to maint N.  If those connections were reversed, your meter might read backwards.  Just a thought...
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Offline lighthunter

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Re: Output voltage adjustment
« Reply #21 on: April 26, 2016, 05:25:15 PM »
Hi Doc!  :)  Great observation on the wiring of small board, i will check, actually, its not.
Running backward i just thought it was because it displays a million kwh and i know i didnt use it that much. Anyway on to the diagrams. I did this rather quickly with limited function software so here goes.
LH

Offline lighthunter

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Re: Output voltage adjustment
« Reply #22 on: April 26, 2016, 05:50:16 PM »
The previous picture shows original connections on pj toroid b4 change.
Power up and measure AC voltage on maintxN to MaintxL Then power off.

The next (2nd ) pic shows connections for step 1 ... After connecting new xfmr. Notice
original PJ connections are still unchanged the newxfmr is just added.
in this way (leaving) 4th terminal of new xfmr disconnected, power up PJ.
and measure AC voltage between "MaintxL" and the yet unconnected 4th wire of new xfmr.
If you measure small voltage, 5-10v, then good, you are phased properly, if high voltage then its.
phased backwar, power off and switch two wires of either winding of new xfmr.

Now once you have measured a small voltage, proceed to measure the voltage.
of the new xfmr (unconnected lead to the one on maintxN) is this voltage 5-10 v less than you measured on maintxN to maintxL? if so great move on to step 2.
LH

Offline lighthunter

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Re: Output voltage adjustment
« Reply #23 on: April 26, 2016, 07:46:04 PM »
Step 2
LH

Offline dochubert

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Re: Output voltage adjustment
« Reply #24 on: April 27, 2016, 11:49:09 AM »
Thanks so much lighthunter.
I always feel more comfortable when I have a schematic to look at.  You have it drawn just the way I figured it to be.  The L1 and L2 designation is what confused me and probably led to my frying my first transformer. 
I see that you have it reversed too.
L1 should be the lower (in your drawing) connection because that's the one that is in line with Maint L and is also the leg that becomes connection P3 and is fused or breakered by the powerjack for output. 
In 110v control board models Maint N is the Neutral lead connected thru P4, and output L2 (if split phase) comes direct from the toroids.  If not split phase and just a 110v output then there is no L2.  In split phase with 230v control boards, the Maint N is also P4 output but now becomes output L2 (230v leg) with neutral coming from the center tap of the toroids directly with no connection to the control board.
So, in my mind I had it "drawn" correctly but reversed the L1 and L2, thinking Maint N was L1 so my connections were wrong for the 115-230v  transformer, and POOF!  I should have just drawn it out myself instead of assuming I had it straight "because its so simple".  Those "simple" and obvious ones are the very ones that get you, along with poor eyesight and old age.  It did me.
So thanks, thanks, thanks.  Seeing it in front of me cleared it up completely for me.  Can't thank you enough.   I'm very reassured now and just have to be patient until Tuesday when my new transformer is supposed to arrive.

Btw, I'm definitely not an expert in transformers, but doesn't that connection of primary to secondary make it an autotranformer?

Btw number 2;  Since I don't (and never will) use the battery charge "feature" of the powerjack, and since the pj people seem to have no problem putting out an unfused 230v leg (I do!), I have re-purposed the second breaker into an output breaker for L2.  I removed the extra wiring and now have no connections to the input terminals of the control board.  I used the wire that originally went from the second breaker to the input terminal and connected it to P4 instead, then removed the original connection from P4 and cut it short and connected it to the other side of the second breaker, so its P4 to breaker, then breaker to L2 output connector.
You would have to do it differently with a 110v control board, with P4 being neutral instead of L2.   Also completely disconnected that 110v input plug under the breakers.  I wonder how many powerjacks have fried from people plugging 110v into the battery charging inputs?  (Probably trips a house breaker somewhere rather than frying the pj, luckily for them)
While I'm on my soapbox about poor powerjack connecting policies, every powerjack I have looked at (4 so far) have the 110v output receptacle reversed polarity.  That is the hot lead (L1) and neutral are reversed.  This would be for the US - I have no idea what other countries use for standard.  Yes, most things plugged in would not care and you would never know the difference, but some things would, and you could get a tingle or short to ground.  Changing/correcting those connections showed me how chincy(cheap) that universal receptacle is so would never connect anything but a small load to it. Push-in connections are poor at best and these are low quality compared to most push-ins.  Ok, I'm done bitching (for today  ;D)
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Offline lighthunter

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Re: Output voltage adjustment
« Reply #25 on: April 27, 2016, 05:06:14 PM »
Quote

" L1 should be the lower (in your drawing)"

Thank You Doc, I will correct this as soon as i get a chance, To be honest.
I just guessed regarding L1 L2 not thinking it would matter but it does, thanks!
A buddy of mine always says if theres a 50% chance of right/wrong, he gets it
wrong 100% of the time :)  I see what he means:).

I havent read your post through yet, will reply more when i do. Thks!

LH
LH

Offline dochubert

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Re: Output voltage adjustment
« Reply #26 on: April 27, 2016, 11:29:40 PM »


Quote
if there's a 50% chance of right/wrong, he gets it
wrong 100% of the time

That's me!

Despite previous bitching, still love my powerjacks
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Offline lighthunter

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Re: Output voltage adjustment
« Reply #27 on: April 28, 2016, 07:18:45 PM »
Hi Doc! I take it your PJ is still working fine then.
Quote

" doesn't that connection of primary to secondary make it an autotranformer?"

I defenitely see the connection  :) "no pun intended" i suppose the answer is yes and no.
technically, an autotransformer has only one winding. We have two here with both wdgs sharing a common conductor.

I did edit pics but seems like this forum has a time limit for modifying a post. Kinda goes against most of our nature as modifying is always more fun:) Maybe i am missing something?? I could post pics again further down. Let me kgnow if ideas.

LH

I really hope this works out for you! I know you will like it when done, voltage is very stable and has just as much torque as the grid until a fuse or breaker clears .

Question, i just got 4 new solar panels. The shipper poked a fork truck into one of em so theyr gonna replace it. I was thinking about ordering a few more with the deal but before i do i wanted to verify performance. So its very cloudy and rainy. I thought.......i know how i can verify performance, i will look at power output on my existing 10panel setup (it read 300w) and i would unplug and add one of these new ones, the power increase will indicate performance.   After I added panel, power actually went down to 200w!!! How can this be????  The voltage went from 254 to 286 to reflect the new voltage. Very wierd, might mean my inverter couldnt do well at that low output poiint??? Or panels are junk and if im gonna use em at all then they hav to be their own string.?

The original panel string was made up of (5)imp 8.8A 22v and (5) 8.4A 29v panels while these new ones are (8.9A ) 37v.  As long as imp ratings are close i should b able to series connect. Any ideas would b appreciated.
LH

Offline dochubert

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Re: Output voltage adjustment
« Reply #28 on: April 29, 2016, 10:53:46 PM »
Hi lighthunter,
As far as your schematics, reposting is fine with me, if you don't mind. Possibly one of the moderators could allow a post "repair", but probably not worth their time and trouble.  I wondered about that time limit to modify a post.  Seems a little odd.  There's doubtless a reason for it, even if not apparent to me.
 
On your solar string, I wish I could give you an answer that makes sense, but I can't.  My experience is that different voltage and different wattage panels strung together can sometimes fight each other, but not consistently.  Sometimes they play nice and seem to put out what you would expect, and then the next day with possibly different sun levels they put out significantly less than the expected total output.  Probably why almost all the solar installers I've heard from strongly suggest buying your string all at the same time and with the same ratings.  Even identical panels added to an existing string that's a few years old can give the result you experienced, but not always.  Sometimes you can add a few panels and they work great; no issues at all.
It seems to be a crapshoot.
Separate strings will probably work better for you, but nothing is definite with mismatched strings.  You might have to experiment some to get it producing proper output.  A diode in each string might help.
Wish I had better info for you.
Almost everybody on this forum is smarter than me, so hopefully someone here can give you a better answer.
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Offline lighthunter

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Re: Output voltage adjustment
« Reply #29 on: April 29, 2016, 11:00:06 PM »
Hi! just wanted to communicate what I found out with new panels.
Even though my 10 old panel array is same IMP rating :o.

The problem was the two diff panels did have same imp rating but.
the power curve was quite different. The new panels work fine above 3 amps.
But the old panels do better by comparison under 3.   Amps ...solution,run 2 separate
strings.

LH.
(Right on Doc!)  ;D
LH