abysmal poor sun performance

[zoneblue]

And 15 minutes later, it's up to 45W, while the tristar is at 133w

Arent we talking about stuff in the noise floor. I wouldnt call that thrashing.

[boB]

Mike, if you want to try PV U-Set %   I would set it to 76%  because this is what I calculate (from your pic)
that value to be from the MS screen.  That's what it was doing based on Voc = 102V and Vmppt = 76V

I couldn't tell what the Voc was on the Classic when I saw the 1400 or so watts at 116V input but
did see 145V at 0 watts which would be at or close to its Voc at least at that time of the day.
That would be 80%.  Doesn't seem that far off but you can try that.

Here is another thing to try when you think the 200 is putting out too low of power compared to the MS.
When the Classic is putting out some power, from the MNGP main status screen, press the soft-left key
(upper-left key) to reduce the PV input voltage.   Press the upper-right key (soft-right key) to increase
the PV input voltage.   It will change voltage if you just hold it in but you might want to just tap it
for about 1/2 second each press to get it to walk down or up in voltage by little steps.

This will adjust it so that you can play with that tracking and see what it is doing wrong.
I think we can get it to work better but either Legacy, Dynamic or VOC% should work
OK if SOLAR mode isn't going to cut it for this array.

thanks,
boB

[boB]

If all is good in that case, then you may want to try either dynamic mode or Legacy P&O mode.

boB, as long as we're on the subject, what is supposed to be the difference between the Legacy P&O and Dynamic?  I tried both and couldn't really see that they did much different from one another.  I did try a wind turbine once with both too, and the Classic did a pretty good job of tracking the turbine on Dynamic.  Not so good on Legacy P&O.  But with solar panels I couldn't see much difference between them.

Chris, the Dynamic mode is supposed to slowly and continuously track the max power point but the Legacy every once
in a while moves the PV voltage below and then above the last MPPV found.  I would not expect either one to harvest
as much energy in a given amount of time compared to wind tracking mode.  It will certainly get it semi-close with
a fairly constant wind speed but as we know, wind never sits still.

boB

[mike90045]

Mike, if you want to try PV U-Set %   I would set it to 76%  because this is what I calculate (from your pic)
that value to be from the MS screen.  That's what it was doing based on Voc = 102V and Vmppt = 76V....

Thanks boB..  Where do I find the place to set U-Set %  Can't find it in the local app.

[Vic]

Hi Mike,

I do not use the Local App ...

Believe that you have a Standard Classis,  with an MNGP.
The U-Set %  is in the Mode menu,  after Dynamic  (see Classic Manual - Page 34).

Scroll down to U-Set,  and use the Right Soft key to access the U-Set setting page ...  you may know this,   just FYI.   Good Luck,     Vic

[mike90045]

The U-Set %  is in the Mode menu,  after Dynamic

got it. Bummer to have to do it on the graphic panel. That's a 600' walk to get to it (around a 20' deep ravine)

SOLAR mode is for sure no good in cloudy weather, P/O does work much better in mornings and evenings.   I'll have to get
another DC breaker, to wire in as a "jumper" to cross connect the array for testing.  Otherwise, I think I would be learning arc welding.

[boB]

The U-Set %  is in the Mode menu,  after Dynamic

got it. Bummer to have to do it on the graphic panel. That's a 600' walk to get to it (around a 20' deep ravine)

SOLAR mode is for sure no good in cloudy weather, P/O does work much better in mornings and evenings.   I'll have to get
another DC breaker, to wire in as a "jumper" to cross connect the array for testing.  Otherwise, I think I would be learning arc welding.

You should be able to use the Local App to adjust things.   Here's what you might want to try...

If you have Wi-Fi at your place and somewhat of a line of sight distance to the controller building, you could
connect up a Wi-Fi Bridge and then you could talk to the Classic over the network.

Might have to place the antenna and bridge in a good location so it can work but then you could have all
sorts of neat communications with that area of your site.

boB

[phxmark]

I have been messing with the mode setting on my girlfriend's house Classic and found that the Legacy P&O works quite well.  Her panels face a more Southwest direction so they don't get any morning sun.  Solar mode stays in resting until there is enough sun hitting the panels to bring it out of resting mode, but the Legacy P&O mode comes out of resting a good 45 minutes before Solar mode.  Dynamic mode is somewhere between Solar and Legacy for coming out of resting.

I have Legacy set at 4 minutes at 12% depth.

[mike90045]

.... If you have Wi-Fi at your place and somewhat of a line of sight distance to the controller building, you could connect up a Wi-Fi Bridge and then you could talk to the Classic over the network....

Yep, I've got a 300' wireless connection for the local app.  It just does not have all the settings that the on-board graphic panel does.  It is pretty handy to be able to change settings, re-start absorb and such remotely.

So, the P&O mode seems to be the best I've found. If I have full sun, I have no problem, it's the gray days that I need every watt squeezed out of those expensive panels & mounts.  Arrays are set for winter tilt, summer, a little lost harvest is nothing.  Too bad the default algorithm can't manage it.   And that nasty sticky stuff on the coin cell holder, got to get in and clean that off,  the new controller has a gob of it in there too.

[zoneblue]

Im just not getting this. The Wh produced by a PV array and charge controller is the area under a bell curve. There is almost neglible area under the margins, so tuning a system for the margins doesnt benefit. Ok so for poor weather. you might want all you can get. The onyl way to tell if any of this turning has any signifcant effect is to compare perfomance curves for identical arrays on identical batterys etc. Theres precious little of this sort of testing around.

[dgd]

SOLAR mode is for sure no good in cloudy weather, P/O does work much better in mornings and evenings.

Sorry to disagree but this is just not what I see. Solar mode works fine in cloudy and misty weather AND it generates more PV power in such weather compared to P&O and Dynamic.
Same in early mornings and evenings.

I have eleven Classic 150s at different locations all in solar mode and have spent time with each switching modes in cloudy and misty weather and also near sunset to test which mode is the optimum.
Every time solar mode wins out.

Legacy P&O seems to be able to work better when the PV input voltage is getting closer to the battery voltage usually because the PVs have not been configured to allow a decent voltage headroom for solar mode mppt. Especially in early morning or later afternoon where there may be partial shading issues or just very low angle insolation.

In your case where charging voltages are so high (for NiFe cells) then the PV input voltage may need looking at, perhaps increased, and solar mode revisited.

I agree with Zoneblue's comments.  Some more meaningful comparisons with less variables would be nice

dgd

[mike90045]

Gotta head to the city for about a week for Dr stuff, Dentist, warranty work on the backup genset and shopping .  Things will be set for P&O while I'm gone.

re headroom.    Yeah, NiFe batteries need high voltages, which is why array is wired for 160V and Classic 200. That planning seems to be ignored by the classic 

I'll try to remember to get the spare 200VDC breaker while I'm out too.

[boB]

Mike.  I don't understand about that sticky stuff around the coin cell battery.

We ship a piece of paper to insulate it when shipped but that shouldn't be sticky ?

Those holders are surface mount so shouldn't have any flux on them.

Maybe someone is adding bubble gum to them ?

[vtmaps]

Mike.  I don't understand about that sticky stuff around the coin cell battery.

We ship a piece of paper to insulate it when shipped but that shouldn't be sticky ?

Those holders are surface mount so shouldn't have any flux on them.

Maybe someone is adding bubble gum to them ?

Mike has been around the block with sticky stuff around the coin battery:

I would mention there has been a few occasions of the glue holding the "Remove" tag to the battery staying balled up on the battery and causing it not to make connection.

Ryan

I just spent about an hour mucking around with this yesterday, and finally got the glue off the inside of the battery holder. Easy to get the glue off the battery.   And of course, got FW upgraded and now a new set of weirdness.

--vtMaps

[Halfcrazy]

Yes I have seen that a bunch of times the glue on the remove tag stays behind effectively insulating the battery