Lite 150 stopped charging

[mobywile]

About 10 days ago I installed a 2nd Lite 150 to handle my entire PV array.  Prior to this I was using one Lite and shutting down some of my PV, some of the time.  When I installed a second 150 it seemed to work OK.  It seemed to be "lazy" coming on-line in the AM, but it eventually began to charge, and I was getting an expected amount of charge.  I have updated my firmware to 1933, done the factory reboot, updated my Remote MNGP, etc. 
Yesterday I noticed that I got about 20% of my expected charge, and today, nothing.  I have disconnected both my arrays and battery, for 5 minutes, and turned the controllers off and back on.  All of the blinky lights do as they should, I think.  In "Follow Me" the # 10 Master is the one that doesn't respond.  It does, however, have COMM because it goes through the SOC drill exactly like the other one, except it goes to "Resting" all on its own sometimes.
3 days ago I was in the battery room and both controllers had the D2 yellow LED on.  FET temps were in the high 80's.   
I am in need of direction, please.  There seem to be a ton of ways to begin searching for a solution, but I am unsure where to start so that I don't "shotgun" this and learn nothing. 
I do have the R132, I think.  Is it on the back side of the board?  Only the top 2 CB penetrations show signs of a device being present.  I know there was a picture in here somewhere but I can't find it again...
Rudderless at 7500 feet.

[Vic]

Hi moby..,

Just to try to get things started ...

So,  each Classic has its own PV array,  right?

What PVs are you running for each Classic -- mfg and model number,  please?

What is the Vin into each Classic?

What is the battery voltage?  What battery type -- Flooded,   AGM,  Gel,  etc (?).

In the Limits menu,  have you looked at,  and reset appropriately,   the Limit ranges for the Max and Min Compensated charge voltage?

In the latest firmware,  there is Temp Comp reference point,  as I read it.  After doing the "Reset",  after the Firmware update,  this reference can be set to 10 degrees C.   This appears to be inappropriate for many battery types --  25 C is the most common Ref temp.

Are either of the Classics "Resting"?

Thanks for the replies,   Vic

[mobywile]

Hi Vic,
Thanks for the prompt reply.  I'll try to get this going with you.  Bear with me.  Long story here which has resulted in this upgrade/hardware change.  Another time...
     
Each Lite has its own array.  I have this sinking feeling that, for some reason unbeknownst to me, my arrays are 
contaminating each other.  I turned off all my panel breakers.  I have 6 - 3 feeding each controller.  I turn on breaker #1 and it      shows up as a charge on Lite #11;  I turn on breaker #6 - which should be the other end of the #10 source, and it still shows      up  charging on Lite #11 also - never wakes up or shows up on as amps in on Lite #10.  Curious...

I have 14 Suntech STP180S-24Adb panels in 2 arrays.  9 to one Lite and 5 to the other.  I have the other 4 to add to the 5 at some point.  I need to build new racking for the remainder.

24V nominal input to the Lites.  I have 16 L-16 Flooded Lead-Acid batteries in a 12V configuration.

Battery temp. is at default 25C.

The Lite that appears to be in revolt is sometimes, but seldom, "Resting".  The rest of the time it does the "Follow Me" to perfection as far as "Bulk" and "Float" are concerned.

I am not familiar with the "Limits" menu.  Enlightenment would be appreciated.

I am changing my system in response to a forest fire here 2 years ago.  Lots of compromised parts and pieces, both indoors and out, which I limped along with until catastrophic failure.  We have been off-grid since 1980 - I am still using stacked Trace 2012s.  Midnite makes the best stuff these days. I remember when the Trace 612 was introduced and we could finally recommend a reliable product to our customers.  Dave Katz was my "connection" back in the day... Davey Rippner kept me from going insane...

So, Vic, help and old dude enter the 21st century and we'll be forever grateful.

[Vic]

Hi moby..,

OK,  well,  am spoiled by using the standard Classics,   and have never used the Local App.  But there must be a menu in the LA to configure the charge setpoints, temp comp,  etc.   On the standard Classic,  there is a Limits menu,  under the Charge main menu.  The later FW has the charge voltage Limited to a range that can be too narrow for FLAs.

If you turned off Follow Me,  and tested each Classic Lite separately,  this might show something.  Also,  if your Combiner is easily available,  and has one breaker for each string of PVs,  this might allow you to see the contribution of each string,  individually.

Assume that you are using the Battery Temp Sensor,  attached to one battery ...

Those PVs are real 24 V jobs,  so that should be enough Vin for a 12 v system.  Are you running single PVs per string?  Or  strings of three on one Lite,  and singles on the other,  just for curiosity.

And,  is there any chance that the PV wiring was damaged in that fire,  which might cause the "contamination" ?

Boy!!  8 strings of L-16,  that must be a bit of a management chore!

OK more later,   Thanks   Vic

[vtmaps]

Each Lite has its own array.  I have this sinking feeling that, for some reason unbeknownst to me, my arrays are 
contaminating each other.  I turned off all my panel breakers.  I have 6 - 3 feeding each controller.  I turn on breaker #1 and it      shows up as a charge on Lite #11;  I turn on breaker #6 - which should be the other end of the #10 source, and it still shows      up  charging on Lite #11 also - never wakes up or shows up on as amps in on Lite #10.  Curious...

OK, it sounds like a wiring problem.  You MUST figure this out FIRST.  All the adjustments to the classics will not help if there is a wiring problem. 

btw, if there is a wiring problem, it will be very difficult on a forum such as this to walk you through the steps needed to diagnose the problem.... you may need to hire a solar professional. 

--vtMaps

[Halfcrazy]

Moby
Can you post pictures here or email them to me ryan@midnitesolar.com

I would like to see as many pictures of the combiner as you can (Well as many as needed to show me all the wiring) I have a feeling you are correct and the 2 arrays are cross talking DC and that will for sure make some very odd behavior on the Classics

[TomW]

Gotta love wiring errors. So easy to make and not so easy to track down.

I agree, you cannot even begin until you audit the wiring and make that right.

Pretty sure HalfCrazy will sort you out if you toss some photos of the combiners, etc his way.

Occasionally, starting from scratch on a mess of cables might be easiest.

I will back out now so the pros can help.

Tom

[mobywile]

Thanks guys.  17F out there today and snowing hard.  Not the best day to be checking wiring. 
I found the limits menu and the settings look good. 
"Combiner Box" is an interesting way to put it.  I did most of this work before 1990 when I put up my old Arco M-55s.  Boy do I wish I hadn't had them compromised during the fire!
I have 3 panels wired in a series string into a Square D QO 2-slot, 4-circuit breaker panel.  So, 2 strings on 3 racks on one ground mount.  Each string has a 20A QO breaker as a disconnect.  These are wired in conduit underground to a "Big Box Painted Gray " where the #4 THHN is up sized to a 2/0 THHN for a 180' run to the house.  Each Positive and Negative have a 2/0 run.  I have 6 strings, or will have when I mount the rest of my panels.  That's 12 pieces of 2/0 180' long.  Those were the days, weren't they...
These are combined in more "Big Boxes Painted Gray" in the battery room and "combined" into 2 feeds for the Lites.  They are very separated, or, at least always seemed to have been. 
Prior to my upgrades, I was using 2 Ananda Power Systems 60A PWM charge controllers with the Arcos.  Worked great for decades.  With no problems like I'm having now. 
I think the probelm, if it is wiring, is somewhere in the array wiring.  I am NOT tearing into it today.  I will disable the "Follow Me" for now, and bring the charging capacity of the entire array below 100A and let it run through the Lite that seems to be behaving normally.
Thanks for the help.  I'll embarrass myself and send some pics later.

[Westbranch]

Each string has a 20A QO breaker as a disconnect.

don't know what is feeding into  that combiner box as far as panels in series but the specs call for a 15A CB not 20A

Series Fuse Rating    15A

http://king-solarman.com/solar-panels-1/suntech-solar-panels/180-watt-stp180s-24-adb-superpoly-solar-panel.html

hth

[mobywile]

Appreciate the contact, Solarman.  I guess we have always assumed that we protect the wire downstream with breakers; 20A with #6 in and #4 out should be fine.  Please don't get started on the wire sizes.  I am aware of what I've done, I think.  All quite short runs and any voltage drop is inconsequential.  If there were going to be problems with impedance, etc. I think I would have noticed at some point since 1988 when I started this project.  I am, however, humbled by all the help I have been receiving and am willing to be proven wrong. 
Your place looks great.  We slowly built our system as well, from a home made - yes, soldered the crystals myself - 15w panel, some AGC fuses in a wood box, used 12v car battery, and one PL fluorescent light.  A monster change from the kerosene lights we were using up 'til then.   Oh, no charge controller.  I pulled a fuse when the battery bubbled!

[Westbranch]

The reason for that CB is to protect the other strings if one panel has a short and starts to backfeed the other strings.

You do not want a CB of  a higher value than the one the Manufacturer recommends.

Oversized wire is good, but can be expensive...

[RossW]

The reason for that CB is to protect the other strings if one panel has a short and starts to backfeed the other strings.

I'm always bemused by this.
If you have two strings, and breakers on each, and one string develops a short (lets say a worst-case dead-short), the maximum current you'll get back will be I(sc) of the other array.
The breakers are specified somewhat higher than I(sc), so there isn't enough current to trip it anyway!

(The circumstances might be different if you have more than 2 parallel strings without isolating diodes, or if they connect directly to a battery - but how is the breaker ever supposed to trip in a one or two string setup?)

[Westbranch]

Ross, I agree with your ''how is it ever going to happen with 2 strings'', however there is an  S at the end of my statement......stringS

[mobywile]

I love this!  I have 3, 24v, 180w panels in series - 5A output each.  The "string" is wired to the input side of a 20A Square D QO breaker, which I use as a disconnect. This is putting 15A at 24V nominal into a 20A rated breaker.  Now, I was taught that breakers are load sized at 80% of the rating.  Therefore, in my small world, I have 16A (80% of 20A) of continuous protection.  Am I missing something?  Doesn't this cover the possibility of a short somewhere?  From the output side of this I run continuous to a "combiner" in my battery room that busses 3 of these inputs to a single wire feeding the Lite.  This occurs on both the + and - sides.  Huge wire, well separated.
I state again.  I am an old fart who got into this stuff 34 years ago.  In the 21st century, I know nothing!  Learn me up, please. 
I have never participated in a forum of any kind before and I am impressed by the "community" of this.  Learnin' new stuff every day.  I have expected temps in the 20's and up tomorrow.  I'll be out there early checking my wiring.  I have a feeling I've sorted out the wiring part.  Maybe then we can get on with the Lite acting weird - to me anyway.

[Westbranch]

I love this!  I have 3, 24v, 180w panels in series - 5A output each.  The "string" is wired to the input side of a 20A Square D QO breaker, which I use as a disconnect. This is putting 15A at 24V nominal into a 20A rated breaker.

NOPE, for series strings you add the voltage so 72 Volts and in series the Amps stay the same, so 5A.  that is why the specs cal for a 15A fuse max.

Now, I was taught that breakers are load sized at 80% of the rating.  Therefore, in my small world, I have 16A (80% of 20A) of continuous protection.  Am I missing something?  Doesn't this cover the possibility of a short somewhere?  From the output side of this I run continuous to a "combiner" in my battery room that busses 3 of these inputs to a single wire feeding the Lite.

NOW you have 15Amps because the 3 parallel strings are being combined ..

This occurs on both the + and - sides.  Huge wire, well separated.
I state again.  I am an old fart who got into this stuff 34 years ago.  In the 21st century, I know nothing!  Learn me up, please. 
I have never participated in a forum of any kind before and I am impressed by the "community" of this.  Learnin' new stuff every day.  I have expected temps in the 20's and up tomorrow.  I'll be out there early checking my wiring.  I have a feeling I've sorted out the wiring part.  Maybe then we can get on with the Lite acting weird - to me anyway.

Hopefully we will be able to diagnose those big grey boxes for you,  I am thinking there is maybe one bad wire/connection