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Charge Controllers and Clippers => The "Classic" charge controller => Topic started by: Resthome on March 30, 2015, 09:45:55 PM

Title: Classic stops output when large load applied and then recovers.
Post by: Resthome on March 30, 2015, 09:45:55 PM
I am seeing what looks like a partial reset issue with the Classic 150 with the latest production firmware. This has happened twice now. Here is the sequence and a question for boB.

First the question for boB, what happens when the Classic is running as a 12v Solar and the battery voltage drops to 11.7 volts. What is the lowest operating voltage for the Classic to maintain it’s charging function?

Now the issue...

1.   Classic is in Float at 13.5v. Sun is late in afternoon.
2.   A 150 A load is applied from an Inverter when a microwave is turned on.
3.   ReBulk is set to 11.5v the Classic Charge Stage goes from 6 to 0 and the Classic output current goes to 0 and the daily kWh resets to 0
4.   At 14 sec the Classic is still at 0 output current but the WBjr begins too show the -150v load.
5.   At 24 sec the Classic is still at 0 output current but goes from charge stage 0 to 4.
6.   At 28 sec the Classic begins to show output current of 66.9A and the Battery voltage goes to 12.7 V
7.   The 150A load from the Inverter was on for a total of 2 minutes or slightly less.
8.   The Classic is now charging the batteries but the daily kWh have been reset and other daily parameters like float time may have also reset.

I’ll attach the data from the Local App as soon as I can. Is this just a case of the initial hit dropping the voltage too low for the Classic to function? Doesn't seem like it is as it stays with that load for 2 minutes and the Classic starts applying output around 28 sec.

Added Local App Live Data Output.

I know I should have grabbed the RFR number but I didn't. If I have to I will try to duplicated it when I return.
Title: Re: Classic stops output when large load applied and then recovers.
Post by: kitestrings on March 30, 2015, 10:44:01 PM
Any chance you're seeing an "OCP error" when, or just after this occurs (and/or a red screen on the local app)?
Title: Re: Classic stops output when large load applied and then recovers.
Post by: Resthome on March 31, 2015, 12:30:17 AM
Quote from: kitestrings on March 30, 2015, 10:44:01 PM
Any chance you're seeing an "OCP error" when, or just after this occurs (and/or a red screen on the local app)?

Did not see either.
Title: Re: Classic stops output when large load applied and then recovers.
Post by: Resthome on April 01, 2015, 10:47:41 AM
Quote from: Resthome on March 30, 2015, 09:45:55 PM
I am seeing what looks like a partial reset issue with the Classic 150 with the latest production firmware. This has happened twice now. Here is the sequence and a question for boB.

First the question for boB, what happens when the Classic is running as a 12v Solar and the battery voltage drops to 11.7 volts. What is the lowest operating voltage for the Classic to maintain it’s charging function?

Now the issue...

1.   Classic is in Float at 13.5v. Sun is late in afternoon.
2.   A 150 A load is applied from an Inverter when a microwave is turned on.
3.   ReBulk is set to 11.5v the Classic Charge Stage goes from 6 to 0 and the Classic output current goes to 0 and the daily kWh resets to 0
4.   At 14 sec the Classic is still at 0 output current but the WBjr begins too show the -150v load.
5.   At 24 sec the Classic is still at 0 output current but goes from charge stage 0 to 4.
6.   At 28 sec the Classic begins to show output current of 66.9A and the Battery voltage goes to 12.7 V
7.   The 150A load from the Inverter was on for a total of 2 minutes or slightly less.
8.   The Classic is now charging the batteries but the daily kWh have been reset and other daily parameters like float time may have also reset.

I’ll attach the data from the Local App as soon as I can. Is this just a case of the initial hit dropping the voltage too low for the Classic to function? Doesn't seem like it is as it stays with that load for 2 minutes and the Classic starts applying output around 28 sec.

Added Local App Live Data Output.

I know I should have grabbed the RFR number but I didn't. If I have to I will try to duplicated it when I return.
Any comments from boB or Ryan on this?
Title: Re: Classic stops output when large load applied and then recovers.
Post by: boB on April 01, 2015, 07:46:34 PM
RH, I don't suppose you could re-create that and video the MNGP screen ?

>>>.   ReBulk is set to 11.5v the Classic Charge Stage goes from 6 to 0 and
the Classic output current goes to 0 and the daily kWh resets to 0 <<<

Sounds kind of like that load is dropping the voltage to the Classic's battery side and is making it reset ?
That is one reason for it to reset its kW-Hour reading of course.

The Classic's auxiliary power supply should operate down to around 6 volts or so.  Maybe you could
try wiring the Classic's positive wire (at least the + wire) more directly to the battery positive
terminal just in case that large surge load is pulling too much current through the Classic wiring.

We have seen OCP's happen because of this and it ~could~ also cause the Classic's input
voltage to drop significantly.  Kind of like a car's starter motor drops the voltage.

The RFR number would show if the Classic reset or not as well.  But you say that the
WB Jr. was working ?  Maybe that was from the Local App ?  If so, you may need to look
at the MNGP display or video it if you can re-create this problem.

>>> 6.   At 28 sec the Classic begins to show output current of 66.9A and the Battery voltage goes to 12.7 V <<<

Went to 12.7 V but from what low V  ?  I don't suppose you were able to catch the lowest battery
voltage during this 2 minute time ?  And does that 150 amp surge start out higher than 150 amps or
just 150 A ?

Re-Bulk won't cause the Classic to stop charging.  An OCP could but that wouldn't reset the kW-Hours.

I think that if the Classic does a reset, the Local App will not necessarily show you that but it would
disconnect from the Classic I would think and that in itself might be a giveaway.
boB
Title: Re: Classic stops output when large load applied and then recovers.
Post by: Resthome on April 01, 2015, 09:11:57 PM
Quote from: boB on April 01, 2015, 07:46:34 PM
RH, I don't suppose you could re-create that and video the MNGP screen ?

>>>.   ReBulk is set to 11.5v the Classic Charge Stage goes from 6 to 0 and
the Classic output current goes to 0 and the daily kWh resets to 0 <<<

Sounds kind of like that load is dropping the voltage to the Classic's battery side and is making it reset ?
That is one reason for it to reset its kW-Hour reading of course.

The Classic's auxiliary power supply should operate down to around 6 volts or so.  Maybe you could
try wiring the Classic's positive wire (at least the + wire) more directly to the battery positive
terminal just in case that large surge load is pulling too much current through the Classic wiring.

We have seen OCP's happen because of this and it ~could~ also cause the Classic's input
voltage to drop significantly.  Kind of like a car's starter motor drops the voltage.

The RFR number would show if the Classic reset or not as well.  But you say that the
WB Jr. was working ?  Maybe that was from the Local App ?  If so, you may need to look
at the MNGP display or video it if you can re-create this problem.

>>> 6.   At 28 sec the Classic begins to show output current of 66.9A and the Battery voltage goes to 12.7 V <<<

Went to 12.7 V but from what low V  ?  I don't suppose you were able to catch the lowest battery
voltage during this 2 minute time ?  And does that 150 amp surge start out higher than 150 amps or
just 150 A ?

Re-Bulk won't cause the Classic to stop charging.  An OCP could but that wouldn't reset the kW-Hours.

I think that if the Classic does a reset, the Local App will not necessarily show you that but it would
disconnect from the Classic I would think and that in itself might be a giveaway.
boB

boB ... 

I only noticed this after reviewing the Local App data that was recorded during this period. I do not believe the voltage went any lower that what is shown. In the data I provide in the Excel sheet. The inverter never kicked off and it would have at about 11.3 V.  It was a microwave turning  on under inverter power so I don't believe there was a surge above the 150A. The lowest voltage is shown as 11.7 V before the Classic recovered and the voltage went back up. See data.

The Classic is wired directly to the battery as is the inventer. So don't believe that the current was being pulled through the Classic wiring. I don't see any gap in the time stamps ( every 2 sec) of the locL app data if there was a reset I would thing the local app disconnect during this period would show in the time stamps.

We are back home so would have to try to record this after we return in a couple of weeks. Just what screen on the MNGP a do you want to see? 
Title: Re: Classic stops output when large load applied and then recovers.
Post by: boB on April 01, 2015, 10:00:05 PM

I would settle to see the MNGP screen when that load comes on.  If you weren't watching
the MNGP, then you may not have noticed if there was an OCP either.
I don't think that the Local App shows this ?  It certainly doesn't log it.

Yeah, the voltage most likely does not drop all too far, otherwise your microwave oven
would not keep running.

Looking for data, now.
THanks
boB
Title: Re: Classic stops output when large load applied and then recovers.
Post by: boB on April 01, 2015, 10:37:45 PM

I see from your data that this is a VERY strange problem that I have no idea of what is
going on. Looks like the Classic did not reset...  I can't see that it did anyway.  I REALLY
wish that this would log the RFR # along with all the other good data.

Will look into this.  Very strange.
Will look to see what version of firmware you are using as well.  I hope that is in here.

A video of the MNGP main screen might help IF you can get it to do this again.


BUT !!!  If it did NOT reset, then WHY does the WB Jr. amps go to zero when your\
microwave oven was drawing  150 amps ???

Here is that little interval where something screwed up.

-13.3
-13.3
-13.3
-13.3
-13.3
0
0
0
0
-60
-60
-149.7
-149.7
-145.1
-145.1

I think the question I have is, what was the Classic doing in that little interval ?
The Local App was definitely reading battery voltage because I see the change
from   11.9  ... 11.8 .....   11.7 volts during that 0 amp interval.

You got a good one here !

You can probably just ignore my last posting.

boB
Title: Re: Classic stops output when large load applied and then recovers.
Post by: Resthome on April 01, 2015, 11:21:31 PM
boB

It's the latest production firmware. It did the same thing two days in a row. The thing that made me notice it was the daily kWh look low. So it went through the logs looking at the kWh a saw it higher that what the daily total was showing that is where I saw it go to zero, along with the current and then I saw the 150A load come back in and realized that was when I started the microwave because it will pull a little under 150A.  Since I had started the microwave the day before when the Classic was in Float I when look at that set of logs and saw exactly the same thing.

Other than this the Classic has seemed to be performing okay at least the limited daily data seems okay. There was one day in February that the daily data was missing though, not sure what that was about, it just did not show that day's data in the log at all. The next day the data was back. Although this is only our second trip up this year where we stayed for a few days to really monitor it with the local app.

I may have seen this a year ago as there was one day that the Classic was showing no current out and I checked the PV array breakes and all was fine and I could not figure out what was going on. I think I reverted to reseting the Classic in that case, but I'm pretty sure the microwave was involved can't be positive but I remember my wife heating her coffee back up. Was only their for one day so don't think I have LA data from then but will go back and look.

Any additional data I can provide let me know. Thanks again for looking at this.

Title: Re: Classic stops output when large load applied and then recovers.
Post by: boB on April 02, 2015, 12:51:47 AM

OK, so while I am looking through code, next time you go to the boat, rack up at least 0.1 kW-Hour and
then start up the microwave to heat some water or something. for maybe 30 seconds.
See if you can repeat that.  If it resets when you do this, do it again and see if it resets the kW-Hours again.

Hopefully you can be watching the MNGP when your wife or whoever turns on the microwave also.

150 (or so) amps /10 is about right for a microwave.  15 amps AC or so ?

Thanks,
boB
Title: Re: Classic stops output when large load applied and then recovers.
Post by: Resthome on April 02, 2015, 12:59:11 AM
Will do, thanks boB..
Title: Re: Classic stops output when large load applied and then recovers.
Post by: Halfcrazy on April 02, 2015, 09:45:18 AM
How big is the battery in AH?
Is it sealed or flooded?
How old is it?

I am wondering if there is a momentary dip north of say 8v on the classics terminals?

Ryan
Title: Re: Classic stops output when large load applied and then recovers.
Post by: kitestrings on April 02, 2015, 10:56:26 AM
"north", or "south"?  Maybe it is relative to which hemisphere you're in ;)
Title: Re: Classic stops output when large load applied and then recovers.
Post by: Resthome on April 02, 2015, 01:02:56 PM
Quote from: Halfcrazy on April 02, 2015, 09:45:18 AM
How big is the battery in AH?
Is it sealed or flooded?
How old is it?

I am wondering if there is a momentary dip north of say 8v on the classics terminals?

Ryan

840Ah 6x2V cell for 2V Flooded - Solar One - New Oct 2012

The Invertor would have kicked off if the voltage went below 11.3V and that did not happen as the microwave continued to run for the full 2 minutes. That voltage drop would have to be quicker than the 2sec voltage interval on the LA data. The lowest voltage recorded was 11.7V by the Classic and the LA. it appears from the LA data that the Classic went from Float, to Float MPPT, Resting, then Bulk MPPT. The question is why RESTING and why did the kWh reset to 0 for the day?? Note in the data I provide in post above there is NO gap in the time sequence. I'm open to all suggestions.

The next time we are up I can attach my Fluke MM and have it record lowest and highest voltage at the Classic terminal during this test.
Title: Re: Classic stops output when large load applied and then recovers.
Post by: Resthome on April 02, 2015, 01:04:24 PM
Quote from: kitestrings on April 02, 2015, 10:56:26 AM
"north", or "south"?  Maybe it is relative to which hemisphere you're in ;)
Classic have been know to do strange things. But I doubt if it cares where it is at.
Title: Re: Classic stops output when large load applied and then recovers.
Post by: Resthome on April 03, 2015, 06:37:13 PM
Okay here is the day I was taking about it happening last year also. And this would have been the firmware before the current production as I just updated it last week.

Note the PV voltage input dropping off, this is what sent me looking at the combiner breakers but they where all okay and the voltage was 40 volts at the combiner. It recovered before I got back to the Classic. This involved the microwave load from Float and the kWh reset to 0 here also. Except it stayed with low PV input for a long period almost like it was stuck in a sweep. But it shows RESTING

See what you think about this data boB. Something sure seems haywire to me.
Title: Re: Classic stops output when large load applied and then recovers.
Post by: boB on April 03, 2015, 10:37:12 PM
Yes, something DOES look haywire there...  But it does not make sense kind of haywire.

There was low watts (5 watts) just before resting (stage 0) so that's OK...

BUT !  Then the kW-Hours reset to 0.0 from 0.1  First strange thing.

What REALLY bothers me is that your INPUT voltage is going from a good 30 to 40 volts
input to battery voltage and then BELOW battery voltage while resting !

It's like your input breaker turned off or there is a bad connection from the PV array...

Bad connections do happen BUT not with the added strangeness of the kW-Hours going
to zero !

AHA !  ALso, I see that right around going to Resting, the FET and PCB TEMPerature jumps
around 10 degrees C !!!  All of a sudden !

FET    PCB

34.2     43.2
34.2     43.2
44.1     52.4
44.1     52.4
34       42.9
34       42.9
33.6     42.6
33.6     42.6
33.5     42.5

I think it may be time for an RMA.
Haven't you done that already once ?

How do you guys come up with all this strangeness ????
boB
Title: Re: Classic stops output when large load applied and then recovers.
Post by: Resthome on April 03, 2015, 11:10:05 PM
Quote from: boB on April 03, 2015, 10:37:12 PM
Yes, something DOES look haywire there...  But it does not make sense kind of haywire.

There was low watts (5 watts) just before resting (stage 0) so that's OK...

BUT !  Then the kW-Hours reset to 0.0 from 0.1  First strange thing.

What REALLY bothers me is that your INPUT voltage is going from a good 30 to 40 volts
input to battery voltage and then BELOW battery voltage while resting !

It's like your input breaker turned off or there is a bad connection from the PV array...

Bad connections do happen BUT not with the added strangeness of the kW-Hours going
to zero !

AHA !  ALso, I see that right around going to Resting, the FET and PCB TEMPerature jumps
around 10 degrees C !!!  All of a sudden !

FET    PCB

34.2     43.2
34.2     43.2
44.1     52.4
44.1     52.4
34       42.9
34       42.9
33.6     42.6
33.6     42.6
33.5     42.5

I think it may be time for an RMA.
Haven't you done that already once ?

How do you guys come up with all this strangeness ????
boB

Hadn't notice the FET temp jump. Looks like for 4 sec and then back down.

This data was from a one day trip and I arrived at around 10:45am and started the LA. I think the Classic had been in some strange state when I got there. As battery is in float and the WBjr is showing a negative along with low watts and 0 input current. That went for over 15 min before the microwave came into play. It couldn't have been a bleed off from coming out of Absorb for that long.  At least I don't think so. At 11:06:41 when it snapped out of it the data then looks normal. It's stranger than I first thought.

If it was a breaker issue on the PV input it would have to be the main PV breaker before the controller. There are 5 -15 amp breakers in the Combiner with 4 awg to the PV main Breaker.

I bought a touque screwdriver last summer and touque all breakers, Classic, and battery terminals so it's not a connection issue.  And the PV voltage and amperage have been good. Does the PV input go through and other circuitry before it is read for voltage?

Yeah this is a refurbished replacement 07/20/14  Midnite Controller - CL11612. The previous SN was - CL13232.

Maybe they can send this one to your lab not sure what it prior history was. Should I send a note of to Ryan to start the RMA process?
Title: Re: Classic stops output when large load applied and then recovers.
Post by: boB on April 04, 2015, 01:00:20 AM

Yeah, let's talk with Ryan about this and more than likely get an RMA going.

The classic just reads the voltage across the + and - terminals.

It's possible I suppose that a weak negative wire could cause problems.
In fact, that would cause strange problems although not sure if it would
cause this problem for sure.

If the negative line is broken or there is a large voltage drop from main
negative to the Classic's negative, then the positive voltages are referenced
somewhat to the OTHER positive input.  Not saying that is the problem here
but more info to know.

boB



But that should not affect the temperatures.
Title: Re: Classic stops output when large load applied and then recovers.
Post by: Resthome on April 04, 2015, 01:17:11 AM
Thanks boB sent a PM to Ryan.
Title: Re: Classic stops output when large load applied and then recovers.
Post by: boB on April 04, 2015, 02:21:38 AM

Also, notice that the BATTery temperature went up almost 3 degrees when
the FET and PCB temperature jumped up too.  This may indicate an issue
with one of the internal A/D multiplexer inputs.


BATT   FET     PCB

19.2     34.2   43.2
19.2     34.2   43.2
21.9     44.1   52.4
21.9     44.1   52.4
19.2     34      42.9
19.2     34      42.9

Although this does not explain (at least yet) the kW-Hours resetting,
one thing you might check before disconnecting that Classic is to have a look
at the "secret" screen that shows the Reason For Resting (RFR). 

From main status, hold down the left-arrow key and then tap the ENTER key. 

Note all of the values.  You can do this when the Classic is Resting.  If the mux is
part of the problem, this may show which channel is the culprit if indeed that
is part of this.

We chalk this one up as being "interesting" at the very least.

boB
Title: Re: Classic stops output when large load applied and then recovers.
Post by: Westbranch on April 04, 2015, 04:28:31 PM
QuoteHow do you guys come up with all this strangeness ????
boB

Same way hackers do it?  Just test to the max! ::)
Title: Re: Classic stops output when large load applied and then recovers.
Post by: Resthome on April 06, 2015, 12:34:28 AM
Quote from: Westbranch on April 04, 2015, 04:28:31 PM
QuoteHow do you guys come up with all this strangeness ????
boB

Same way hackers do it?  Just test to the max! ::)

Yeah, if it wasn't for the great monitoring capability of the MidNite Classic we would never see all this strange stuff.