Input voltage from panels stays at 5vdc regardless of solar panel voltage

[TomW]

Craig;

Don't be discouraged. This type of remote troubleshooting is tough to do. We never know the knowledge / skill level of the poster. With many years of experience, many of us forget the raw basics because it would be the first things we do without even conscious thought.

Finding missing voltage is usually started by tracing back at every connection from the point it is "missing" to the source. It was my first thought when I read this but I figured someone would mention it but the over thinking got started and I left it  alone. They were all trying to help.

Bad or improper  connections are a cause of many problems.

Just saying...

Tom

[tecnodave]

Craig,

There is a procedure that is referred to as a VMM, (Vulcan Mind Meld),  to do this turn off p.v. input breaker, then battery breaker to Classic, wait 20 seconds , press and hold left arrow and right arrow buttons, and while continuing to press both arrows turn on battery breaker ,continue pressing both buttons until you see the greeting screen that will ask you to confirm battery voltage.  At this point you have done a factory reset and all values that you have programmed will be gone and need to be re entered.

Just turn off power will not reset to factory values as there is a small battery in the MNGP control panel that remembers values programmed in such as voltage charge rate, etc,etc,.


Rule number one when troubleshooting,  start with the absolute minimum , make that work , then add devices , programming , all else one step at a time. This will make it much easier to diagnos than trying many things at once.

Suggestion try just one 250 watt panel by itself, then the other......I.e. Little steps.......way easier to see fault mode when it happens


td

[wa_desert_rat]

Rule number one when troubleshooting,  start with the absolute minimum , make that work , then add devices , programming , all else one step at a time. This will make it much easier to diagnos than trying many things at once.

Yes, I had been doing that when the issue of zero volts indicated arose. I am a newbie on this forum but not in real life. My first solar panel project was in 1982. This, however, is my first go at a series installation with such a sophisticated charge controller.

I didn't think that the topic heading could have been more clear. Early on I asked for a way to reset the 150 but things descended into questions designed, apparently, to solve some other problem. But I do understand how forums work so I should not have been surprised.

The Vulcan Mind Meld procedure is good to know. Thanks for that tip. Software driven devices can sometimes benefit greatly from a chance to re-think plus I had hurried through the original wizard and was wondering if I had managed to tell it something that it didn't need to know. I just thought it would be quicker to ask you guys than try to find it in the manuals.

Craig
[/quote]

[Vic]

Hi Craig,

Will sure try to second what TomW mentioned.   All of the posts in this Thread came from a number of people,  all of whom were trying to help YOU.

Your Subject is clear.  BUT there may not really be nearly enough data from which to draw many conclusions.  So,  many of those like me,  try to guess the nature of your system in an attempt to keep from asking you a series of questions,  before mentioning any of our guesses.   The guessing approach often gives a poster more answers or at least some things to check,  and allowing the OP to fill in some real data on the subject system.

In the post above,  you mentioned "ZERO volts indicated" as a situation that arose.   If this is in reference to having zero input volts input indicated on the Classic status screen,  then this can be a different situation than an indication of 5 V in.

I have a new guess ...  you did mention that one morning,  you noted 5 volts input read on the Classic,  and 55 V measured at the PV in busbar "behind" the Classic.   It could be possible that if this was very early in the AM,  that what you were measuring on the busbar was Voc,  and the Classic was resting due to insufficient current available to justify running the Buck Converter that would charge your battery.   Also,  if there is any shading,   there can be a huge reduction in power available,  and this could cause a CC to Rest,  and so on.

In general PV voltage readings can be misleading,  as indications of available power.   Particularly when bright sun is not directly illuminating  the PVs.

Regarding the Firmware Version number,  you should be able to find it by pressing the Status button a number times.  It is about the last screen that you will find on the MNGP display on the Classic.

If you see the Wizard,  your Firmware is fairly outdated.  You will want to update to a  more recent version of FW.  It might be that the FW is down-rev enough that the FW version will not be displayed on the Status pages.

Just my drive-by guesses.  Please do not get too frustrated,  the crystal ball is clearing.   Vic

[boB]

Craig, another thing to try measuring with your multi-meter is the third pin from
the left end of the horizontal connector shown in this small attached picture....

The pin right below R24.  Multi-meter negative lead can connect to your negative
battery or PV terminal or screw on the main terminal block.

This third from the left pin of that top-side connector is in the middle of the
resistor network coming into the control PCB from the terminal block.
It will read a lower voltage than the actual PV +  terminal on the terminal
block, but will help determine if maybe you have a bad resistor or something
in that Classic.  Depending on which Classic you have, this voltage will be
different.  Take note of both terminal block voltage and pin 3 voltage that
you measure, please.  We will see what we can tell from this information.

Thanks,
boB