Aux 1 Waste Not High, Float High or PV High not turning off

[phxmark]

I have an inverter that charges the batteries when the sun goes down.  During the day, the inverter/solar run the house loads.  At night, the inverter goes back on-grid and can charge the batteries.

I was using PV High for Aux 1 control, but discovered that if Aux 1 is on when the inverter goes to resting, Aux 1 will not turn off unless I manually turn it off.  If Aux 1 was already off when the CC went to resting, Aux 1 stayed off.  Problem is, when the CC goes to resting, the PV Voltage in rises to Voc causing Aux 1 to turn on.

I really want to be able to trigger Aux 1 when the CC isn't resting and the CC is in Float mode.  The Float High mode triggers off battery voltage, too when the CC isn't charging and is in rest mode.  This may be by design or just an overlooked bug.

[dgd]

I really want to be able to trigger Aux 1 when the CC isn't resting and the CC is in Float mode.  The Float High mode triggers off battery voltage, too when the CC isn't charging and is in rest mode.  This may be by design or just an overlooked bug.

This does not seem right to me. The FLOAT HIGH (or low) mode does not trigger off the battery voltage, at least not in my Classic. If this was the case then when the controller is in BULK MPPT on its way up to ABSORB voltage and passes the FLOAT set voltage then the AUX FLOAT HIGH would be enabled. But that does not happen, the FLOAT HIGH is only enabled when the Classic actually goes into FLOAT mode,
I used this to enable DC water heating only when the batteries were in FLOAT.
As the sun goes down and FLOAT moves to FLOAT MPPT then the AUX float HIGH is disabled and goes LOW.
It doesnt matter what other battery charging source there is, once the Classic goes to resting it will not start up again until there is power input from the PVs the next day.

Unless its my Classic that has a problem then there must be some other reason why your CLassic is not disabling the AUX FLOAT HIGH when it drops out of FLOAT mode.

dgd

[phxmark]

Hi dgd.  Are you using the latest firmware on your Classic?

Mine doesn't behave this way when I set Aux 1 to Float High.

[phxmark]

Classic 200V (rev 4)
Firmware:
- MGNP Rev: 1608     
- Classic Rev: 1609
- Network Rev: 1597

[dgd]

Hi dgd.  Are you using the latest firmware on your Classic?

Mine doesn't behave this way when I set Aux 1 to Float High.

My 150 is using a previous 1401/1194 with Float High on AUX1.
I uploaded the latest firmware and left everything else the same and it appears that AUX1 is behaving as before.
I also wired in a spare 150 which has no input, no PVs and I set it to Float high on AUX1. This 150 was always in resting mode (0:unknown) and although it showed the battery voltage increasing as the other Classic charged the batteries through bulk mppt to Absorb then back to Float it never triggered AUX1. This sort of proved that AUX1 float high will only trigger when the Classic is actually in float and NOT based on battery voltage.

I could not find any way in the Classic setup to stop AUX1 from going off when the Classic dropped out of float.
Maybe I'm missing something here    as I could think of uses for a latching type control of AUX, once a condition is met to enable an AUX then another user defined condition has to be met to turn it off.
ALthough that would probably require some logic table type of setup for AUX  (we almost had this at one stage in the
MyMN exception reporting system)

I assume you have done all the obvious things like reloading the Classic firmware, factory reset then reprogram, check the SSR is seeing the proper levels of ON/OFF voltage, etc..

dgd

[phxmark]

Just for grins and some testing, I placed the Classic in Perturb and Observe Mode.  Waste Not is now behaving the way I want it.  Must be a firmware issue.  If I had the Classic in Solar or Dynamic Mode, Aux 1 wouldn't do what I wanted it to do.

[Vic]

Hi phxmark,

Good that you are trying a different MPPT Mode in the Classic (IMHO).

In looking at the specs for your PVs,  seems that they have a Vmp of about 30.2 V,  IIRC.   This is on the low side,  if you do have strings of only two PVs -- 60.4 Vmp fort the string.

AGM batteries would do better in this low-ish input voltage configuration,  as AGM batteries usually do not need a real EQ.  However,  in the summer heat,  you may not have enough input voltage to get the most out of the CC.

Just my opinion.   Good Luck,       Vic

[boB]

Phxmark,

  Maybe you could try re-programming that same Classic and see
if it acts differently ?  I haven't heard of a Classic having to be re-programmed
after it was updated, (I don't think ?), but maybe it didn't update quite
right ?

boB

[phxmark]

That is the only thing I didn't try after the update.  I did reset it to factory defaults after the update.

Aux 1 is working the way I want it now.  It turns off when it goes to resting.  For some reason, Aux 1 behaves differently when in P&O mode.  If I have the Classic in Solar or Dynamic mode, Aux 1 will stay on when the Classic goes to resting mode.  I actually seem to be getting more power from my array when in P&O mode, too.  Go figure.

I am way happy now that things are working the way I want.

[boB]

Great !  Glad that it is working well now.

I guess it doesn't hurt to put more modes than one might think they would
need in there !

Merry Christmas, folks !

boB

[dgd]

Phxmark

That's an excellent observation Vic made as with only 2 panels of 30v Mpv in series that is not likely giving the classic enough voltage headroom to be doing mppt effectively.
And in not perfect conditions they may be at lower voltage .
I suspect that's why p&o mode is working much better than normal solar mode.
Have you considered reconfig the PVs into two strings of 3 in series and perhaps trying solar mode again. It would be interesting to see if this also maybe fixes the aux behaviour as well
Just a suggestion...

Dgd

[phxmark]

Phxmark

That's an excellent observation Vic made as with only 2 panels of 30v Mpv in series that is not likely giving the classic enough voltage headroom to be doing mppt effectively.
And in not perfect conditions they may be at lower voltage .
I suspect that's why p&o mode is working much better than normal solar mode.
Have you considered reconfig the PVs into two strings of 3 in series and perhaps trying solar mode again. It would be interesting to see if this also maybe fixes the aux behaviour as well
Just a suggestion...

Dgd

I rewired the panels to be 3 in series for 90v per string.  I set the Classic to Solar mode.  I let it run and monitored it for a couple of days.

Observations:
Aux 1 stopped working the way I wanted it to.
Power production was not as much from the system as it was in P&O mode.

I have since gone back to the Legacy P&O Mode and set it for 15% and I am getting better power production from the array and Aux 1 is back to working the way I want.  I left the panels configured for 2 stings of 3 panels.  Right now Watts on the app is hovering around 1300 Watts.

So far today(as of 4:45PM AZ Time, the system has generated 8.1kwh using Legacy P&O Mode.  I have only been able to get a maximum of about 6.8kwh under solar mode.

[dgd]

I rewired the panels to be 3 in series for 90v per string.  I set the Classic to Solar mode.  I let it run and monitored it for a couple of days.

Observations:
Aux 1 stopped working the way I wanted it to.
Power production was not as much from the system as it was in P&O mode.

There is still something wrong but at least Legacy P&O mode seems to work for you, and the Classic hardware seems good. Solar mode should be more efficient than LP&O.
But you have already reloaded the firmware?
dgd

[phxmark]

I reloaded, reset and reconfigured the Classic.

I have checked all the connections from the panels to the Classic.  All are good.  I have a 50ft run of 8Ga wire from the panels to the Classic.  Voltages at the panels are within a few tenths of a volt at the Classic so the wire run doesn't appear to have much, if any, losses.

[Halfcrazy]

Is there any shading? Legacy P&O does better when the array presents multiple MPPT voltages that would typically be found with shading or mismatched panels. It also performs better when the arrays MPPT voltage is at or below battery voltage.

Ryan