Help with setup of my 200

[Joesouth75]

Hello all...here's what I have.  Four 320w 24v sun Edison panels 2pair series then paralleled together. The panels specs: 45.9voc, isc 9.26a, impp 8.68a, vmpp 37.0v.  I have a classic 200 going into 4 Trojan t105 wired for 24v system leading to an aims 2500w 24v inverter.
now here's my question(s) I'm getting really good sun for about 6hrs per day and the classic is showing 80v 224w and 8.2A.  Shouldn't I be producing more watts?  I have the bulk, float, EQ charges set to 29.6, 27,32.4 per Trojan specs but it seems I can only turn on lights.  my ceiling fan wont even run.  what am I doing wrong?  Please help.
Joe

[Westbranch]

what stage of charge are you quoting here? Bulk or Absorb ? start of that stage or the finish?
What is the state of charge of the battery?
What loads are you supplying at the time of reading 224W?
All needed information to figure it out..
more questions later...

[boB]

What Westbranch said...   If the charge stage is Absorb or Float, then the power will be low.

If the Classic is in BULK MPPT or Float MPPT say, the input voltage should be around
80% of the open circuit voltage (Voc)

I know that the label says the Voc should be around 90V from two panels in series.
But due to temperature differences, it can be different than that.

If the Voc is 90V then the input voltage would want to be around 72 volts for maximum power but
max power can only happen in an MPPT mode like Bulk or Float MPPT or EQ MPPT.

One trick to try is to change the MODE from SOLAR to  Legacy P&O  to double check the
tracking is working properly.  Each Classic is tested at the factory before it goes out but
sometimes things happen.

Let us know how it goes please.

boB

[mike90045]

That seems like a lot of inverter for a smallish system

When you say lights come on, but the fan won't, are they both running off the inverter ?

[Joesouth75]

Yes both off the inverter. The box fan hums n turns slow, then I hook up the generator and it runs fine. I have 6 panels but only using 4. That's why my inverter is sized that way. I want to eventually run my small well pump and all of the cabin on the solar array. I guess I'm just not that familiar with the classic 200.  Does anyone have a step by step setup/programming guide for a 24v 1280w system.  Or links to them.
Joe

[Vic]

Regarding the humming and slow-running fans,   this could be an inverter issue.

When the fans are not working well,  what is the battery voltage,  measured at the battery terminals?
If possible,    also measure the DC voltage at the DC terminals of the inverter.

What is the battery voltage shown on the Classic?

What is the AC output voltage from the inverter?

What is the input voltage (upper left on the LCD display)?
What charge stage is the Classic in (lower right on LCD)?

You might want to check and re-torque ALL DC and AC connections,   and measure the DC voltage of each battery ...

Please give us as much of this info that you possibly can.

Just to try to get your troubleshooting of the system started.

Thanks for the added info.  Good Luck,   Vic

[Resthome]

Hello all...here's what I have.  Four 320w 24v sun Edison panels 2pair series then paralleled together. The panels specs: 45.9voc, isc 9.26a, impp 8.68a, vmpp 37.0v.  I have a classic 200 going into 4 Trojan t105 wired for 24v system leading to an aims 2500w 24v inverter.
now here's my question(s) I'm getting really good sun for about 6hrs per day and the classic is showing 80v 224w and 8.2A.  Shouldn't I be producing more watts?  I have the bulk, float, EQ charges set to 29.6, 27,32.4 per Trojan specs but it seems I can only turn on lights.  my ceiling fan wont even run.  what am I doing wrong?  Please help.
Joe

Joe,

Something is not right. You should be able to get ~70% of your rated panel wattage of 1280W in Bulk MPPT mode with high sun on you panels. Are you quoting 8.2A from the panels (IN). Or is this what's going to the batteries. If the 8.2A is from panel and you have 2P2S configuration you should have ~15A max from panels with high sun. BTW, You can not set Bulk voltage so I assume 29.6V is the Absorb setting.

Like WB said we need more information.  Like when are you seeing these readings, what stage is the controller in, what time of day, full sun no shade on panels? If you have the MNGP display a picture of the different status display would be helpful.

How big a load are you running?  You have a very small battery bank for that size inverter. You will never run all your planned devices off that battery bank. Are these quoted reading with inverter off ? Is this a new setup or has it produced more watts before? What size wire are you using and distances for panels to Classic and from Classic to batteries? Are you using a Combiner box for you solar panel string connections?

Attached is from MN String calculator and approximately your values if I understand how you have your panel wired 2P2S.


Please reply to Vic's questions it will help to determine what you are seeing with you system. 

[Joesouth75]

Yes both off the inverter. The box fan hums n turns slow, then I hook up the generator and it runs fine. I have 6 panels but only using 4. That's why my inverter is sized that way. I want to eventually run my small well pump and all of the cabin on the solar array. I guess I'm just not that familiar with the classic 200.  Does anyone have a step by step setup/programming guide for a 24v 1280w system.  Or links to them.
Joe

[Joesouth75]

With the 4 panels that I'm running, you're saying my battery bank is to small?
I have 6ga running from panels to controller about 20ft run. No combiner box just panels to 6ga then a breaker then controller.  Then 6ga from controller to batteries with a breaker between about 3ft run. Batteries are four 6v series together with 1awg all equal length and fused 1awg leads to inverter equal runs of 3'6". I will be at cabin on Monday I will take a picture and try to post it so can see my setup.

[Vic]

Hello Joe..,

Regarding the setup of the Classic 200;

First,  you will want to find the recommendation for Charge settings from Trojan  --  the initial settings that you have noted in the first Post look to be a good start.

The Absorption time setting in the Charge menu  will depend upon how deeply-discharged the batteries were.   Greater Depth Of Discharge (DOD) means that a longer Absorb time will be needed for a full recharge.   A 2 hour Absorb time is a good place to start.

Almost all T-105 batteries are Flooded (batteries with easily removable caps on the top of the batteries).   This is great if you DO have Flooded batteries,   as you can actually measure how fully charged are the batteries (State Of Charge  --  SOC).   You do this measurement with a Hydrometer.   If you do not have a Hydrometer,  you can find a  good ALL GLASS one at an Auto Parts store,  like NAPA.

Here is a Link to an Article on Measuring Specific Gravity (SG) of Flooded batteries from Surrette battery:
http://support.rollsbattery.com/support/solutions/articles/4347-measuring-specific-gravity

The only difference between your Trojan battery SG measurement and the SG table in the article,  is that the Trojan batteries use a higher SG electrolyte (acid)  inside the batteries,   and you will want to use the SG verses SOC table from Trojan as a guide.

More later.   There is a bit of detail on designing,  setting-up,   and monitoring an Off Grid power system,   but  much of this is fairly straight forward.

You will want a good MultiMeter along with your good Hydrometer,  to help you measure what your system is doing,   at any one point in time ...

More later,   Vic

[Joesouth75]

Vic
I used the numbers given off this special sheet from Trojan. The bulk float and equalize for a 24v system.  Is that all I would have to enter in the controller?  Does the controller do the rest?

[Vic]

Hi Joe,

In the charge menu,  you will want to enter the Temperature Coefficient for charge voltage,   believe that Trojan T-105 batteries are now using --3 mV/degree C.

You will want to check,   and think about the Limits (voltage Limits of the Temp Compensation).   These Limits will depend upon the expected range of battery temperature over the year ...   more on this,  later.

Be certain to install the Battery Temperature Sensor (BTS),  mid-way down the side of a battery.   And,   if the AIMS Inverter also has a BTS,  install this one next to the Classic one.

For most Charge Controllers (CCs) like the Classic,   there is NO setting for a Bulk voltage.   You will use the Absorb voltage setting in the Charge menu,  instead.

Hope that you have a way of downloading the Classic Manual.   The Quick Start guide is a good summary of what you need to do to bet going,  but the full Manual is also a big help.

Additionally,  if you have Internet access at your Cabin,  this will help you get fairly quick answers to any further questions that you may have when at the cabin.

On the MidNite Solar site there are a number of Documents,   the Manual version 2056 is the latest,   and is down the page on the following Link:
http://www.midnitesolar.com/documents.php?productCat_ID=21&productCatName=Charge+Controllers+-+Classics&model=CLASSIC 200&product_ID=257&act=

You might want to survey some of the other Docs on that page.

Need to travel to another site now,   but will check back this PM.   Many others here can help flesh out more details.  Good Luck,   Vic

[Westbranch]

Joe, I noted that you have CB's in line but don't have a combiner(box) in your setup yet. ie:

http://www.midnitesolar.com/products.php?menuItem=products&productCat_ID=9&productCatName=Combiners

Based on your description of 2S3P sets of panels, a MNPV3 would work , to combine your 3 strings of 2 panels each.

What do you have right now to combine the wiring, Positive and Negative, of the 2 arrays?

It is highly recommended that you do use a combiner of some sort, especially when, like now, you are trying to determine why you are not getting full power from your system. The combiner allows you to check each string , one at a time, for output by simply throwing the CB's  for the chosen string(s) you want to eliminate.

PS when you have more than 2 strings, you need to have a method of stopping a back feed from a shorted panel to protect the entire array!

Here is a simple wiring diagram,  showing a KID CC rather than the Classic, that is closest to your system design.  I am using this as it is much cleaner than the ones for the Classics.

http://www.midnitesolar.com/pdfs/Kid_24V_2p_Series_REV_B.pdf

You asked about specific instructions for the Cl 200, there are general instructions for ALL Classics as there is essentially no difference for any of the models other than the wire sizing, which is determined either by the size of the array and the loads to be placed on the batteries. I did note that some of the wiring may be a little light when the whole system will be in place.
hope this helps.

[mike90045]

is your inverter mod sine or Pure sine (waveform)

Mod sine is fine for lamps and cheap things, but terrible to try to run motors off of, noise, excess heat

[Resthome]

With the 4 panels that I'm running, you're saying my battery bank is to small?
I have 6ga running from panels to controller about 20ft run. No combiner box just panels to 6ga then a breaker then controller.  Then 6ga from controller to batteries with a breaker between about 3ft run. Batteries are four 6v series together with 1awg all equal length and fused 1awg leads to inverter equal runs of 3'6". I will be at cabin on Monday I will take a picture and try to post it so can see my setup.

Thanks pictures of the various status displays from the Classic may give us a clue. And yes you battery bank AH rating is only 225AH you will not run a cabin and water pump (What size pump?) without draining this bank IMHO. Remember you should not go below 50% DO or 112AH. And for long life of you batteries you should no go below 70% IMHO?  You need to access all your loads and how long they occur. And please tell us when you saw the readings in you OP and where were you reading these values and what stage was the Classic in.