Relay issue?

[laszlo]

I have an old Classic 200  -- ''2011 vintage --  and I've already harvested  with it around 20MWh so I'm not complaining. In fact, I am curious about failure modes in fielded Classics that are pushing lots of power like mine does, since this can feed back into future product development.

Symptoms:
Yesterday during the day I saw from local app Classic did not charge at all, but could not come to diagnose it during the day.  I saw (after dusk) that there was voltage on the array because the LEDS's on the MNSDPs  were lit. After I power cycled eh Classic, the LEDs went off.

This morning same thing happened, no charging, mode MPPT set, and loud clicking of the relay from inside the Classic.  Array voltage  was normal open circuit voltage, and mode was MPPT.

I was able to get charging started by power-cylcling Classic  again by turning off then on the breakers.

Discussion:
It does seem like a sticky relay to me -- no big deal.  What are my next steps? 

[boB]

Look at the input voltage from Resting to MPPT and notice what it is when it says it is in
BULK MPPT mode...

The input voltage usually tells most of the story.  What does the battery voltage read
when it is Resting vs.  MPPT ?

The worst case is if the PV input voltage goes to zero volts. 

boB

[laszlo]

It was around 80V input voltage -- normal for my PV array open circuit voltage.   

Attaching mymidnite screenshot for yesterday (Friday Apr 3). The date is off 1 day + on mymidnite but you can see all day long no power production then it came up briefly in the afternoon.

Today I started it up manually and worked fine.   At dusk currently,  it is in Resting state, with cause "code 9, negative current". Array voltage going down, currently at 39V - see attached local app screenshot.

[boB]

Looks from the screens that things are OK.

If production seems lower than usual, check wiring or "things" on modules maybe.

boB

[laszlo]

Yes, everything works after I manually cycle the input/output breakers after the sun's up.

So for now, I pulled the Classic and replaced it with an MX-60. "Mind meld" -- sound familiar?  Using the Wbjr and the internet off the Classic, so I can keep an eye on things.