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Charge Controllers and Clippers => The "Classic" charge controller => Topic started by: Resthome on November 08, 2014, 02:02:02 PM

Title: Classic Stuck measuring VOC ??
Post by: Resthome on November 08, 2014, 02:02:02 PM
It appears my Classic 150 got stuck in a mode where it was measuring VOC of the panels. I’ve never seen this before. Not sure of the situation that caused it but when I arrived and checked the Classic it was in Float. I turned on the inverter and my wife used the uWave for about two minutes. This is the biggest load I have on the boat and is usually drawing 150A from the invertor. The uWave shut off and I went to check the Classic MNGP and the Main Status display was show PV In around 40v Amps 0 the VOC reading was also around 40v. The battery voltage was showing 13.4v and Float but also 0 Amps.  The WBjr status was showing -3.4 Amp.  I checked the solar breakers and everything looked fine. I then got my clamp on amp meter out and check the amps at the batteries and it was -3.4 Amps the same as the Classic was showing. I decided to put the Classic in Equalize mode to see if it would come out of whatever mode it was in because it was no long charging the batteries. The MNGP status showed batteries voltage at 15.3V and Equalize was flashing on the MNGP. The 15.3V is my Equalize set point. But the Amps from the PV and Batteries were both showing 0 Amps still. So while scratching my head I went to my Link 10 meter and the voltage was showing 12.5V and -3.4 Amps. Running out of ideas after checking various settings and knowing I was only going to be there a few hours I decided to reboot the Classic and do a VMM. The Classic rebooted and I turned on the PV breakers and the Classic went to Bulk MPPT mode with the Battery Voltage climbing and the Amps around 45 Amp.   The voyage quickly settled in around 14.4V which is my Absorb set point and went to Absorb.  PV was showing around 37 v and the Amp now around 18 Amps.  The WBjr was now showing around 41 Amps.  The only thing I can think of was the Classic somehow got stuck when it went to open the PV circuit to measure the VOC. 

boB any clues to what might have cause the Classic to get stuck in this mode?  What really takes place software and hardware wise when it measures VOC?

The Classic definitely was not in resting mode. It was in Float mode when it happened and it definitely was not charging the batteries and would not come out of that mode. I did not think to turn the Solar Mode to Off to see what would happen. Would have tried more troubleshooting if I was going to be staying but that was not the case yesterday. Hopefully it doesn’t get stuck in this mode again since we are not going to be making another trip until around the end of December.  :-\
Title: Re: Classic Stuck measing VOC ??
Post by: Westbranch on November 08, 2014, 02:23:33 PM
RH, I am wondering if you had pressed the < key to see the if Classic had captured a RFR (reason for resting)..????

I had a problem that I investigated, and wiped out the needed  RFR (I believe)  by doing a VMM too... The only RFR I found was 'low light'.

boB will probably ask for the RFR if you saw/remember it...
Title: Re: Classic Stuck measing VOC ??
Post by: Resthome on November 08, 2014, 06:08:24 PM
Quote from: Westbranch on November 08, 2014, 02:23:33 PM
RH, I am wondering if you had pressed the < key to see the if Classic had captured a RFR (reason for resting)..????

I had a problem that I investigated, and wiped out the needed  RFR (I believe)  by doing a VMM too... The only RFR I found was 'low light'.

boB will probably ask for the RFR if you saw/remember it...

Yeah, I didn't get the last RFR but I don't think it would apply because it definitely was not resting according to the MNGP anyway. It was displaying Float and when I switched it to Equalize it changed to flashing Equalize like it normally would but no Amps out from the panels per the MNGP. And it had plenty of PV voltage for a 12v system in fact to me it looked like it was measuring VOC for the PV voltage but maybe not. The panels are 5 strings of 2. Voc is 22.1V  and Vmp is 17.7V.
Title: Re: Classic Stuck measing VOC ??
Post by: Resthome on November 09, 2014, 06:12:47 PM
The LA did catch some of this. So I will attach that data here.

Title: Re: Classic Stuck measing VOC ??
Post by: Resthome on November 09, 2014, 06:21:08 PM
And the WBjr Graph during this event.

Title: Re: Classic Stuck measing VOC ??
Post by: boB on November 09, 2014, 10:29:57 PM
Well John, you got me there !   I could see the Classic maybe getting off on its current setting but
not the voltage reading unless it STAYed wrong.

What I have seen before is a full (or bad) battery that takes little current to keep it at
float voltage and then when the charger is turned off for a couple minutes and turned
back on again it would come back up in Bulk/Absorb (higher Vdc) and pull lots of current
for a little while or few moments.

Also, if there are other charging sources keeping the battery at float, the Classic won't
push any power out to keep it there.

So, I'm not sure what's going on without actually seeing it.  I can usually figure things out
if I can see the system.  I will look at your XLS file.

boB
Title: Re: Classic Stuck measing VOC ??
Post by: Resthome on November 10, 2014, 04:14:53 PM
Quote from: boB on November 09, 2014, 10:29:57 PM
Well John, you got me there !   I could see the Classic maybe getting off on its current setting but
not the voltage reading unless it STAYed wrong.

What I have seen before is a full (or bad) battery that takes little current to keep it at
float voltage and then when the charger is turned off for a couple minutes and turned
back on again it would come back up in Bulk/Absorb (higher Vdc) and pull lots of current
for a little while or few moments.

Also, if there are other charging sources keeping the battery at float, the Classic won't
push any power out to keep it there.

So, I'm not sure what's going on without actually seeing it.  I can usually figure things out
if I can see the system.  I will look at your XLS file.

boB

boB, No other charging sources. The invertor does not have a built in charger. The batteries were full and take very little current to keep them at the float voltage. The only thing that I can think of is the UWave pulling 150+ Amps for ~2 minutes should have thrown the max solar amps at the time to help keep it at float voltage. Either I didn't have the LA running at that time or it was already in that state and stayed there  during the uWave use. Not sure as I didn't look at the Classic MNGP until after the uWave use. What baffles me is and you can see it in the LA data dump is even when I put it in Equalize the voltage changed instantly from 13.6 to 15.6v but showed no current and it would have taken some current above the 0.4 Amps shown to get the voltage up. Later after the reboot and in equalize it was taking ~20 Amps. The WBjr also showed a -3.6 Amp which would have been about right for the load with no solar. This was verified with a clamp on amp meter.

Will see if you see any thing in the data. I'm also at a loss of why there doesn't seem to be a gap in time on the data during the time while I rebooted. The time at 11:05:13-11:06:41am I believe is after it rebooted and I had the PV breaker off for a minute while I changed the Classic settings. The raw time code is hidden in col B. I did not cycle the PV Breaker before powering the Classic off. I did however cycle the 5 breakers in the combiner but they all looked good. And I would think if the PV breaker had a problem there would be no little PV voltage showing not the 40V.