Author Topic: Problems since winter storm  (Read 147 times)

Tobit

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Problems since winter storm
« on: February 20, 2021, 12:43:11 PM »
Hi guys. I need help figuring out what is going on with my off-grid system.  It was working fine before this recent winter storm. 

I just returned to the cabin from spending a week in town to escape the frigid temps.  I cleaned the snow off the panels but found I'm not producing much energy at all despite a gorgeously sunny day.  I should be seeing 20A ointo my battery bank right now but I am only seeing 0.5 to 1A and the KID is switching between "Resting" and "BulkMPPT" modes frequently.  Could I simply be having a moisture issue with one of the connections at the panels?

mike90045

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Re: Problems since winter storm
« Reply #1 on: February 20, 2021, 01:14:27 PM »
Even a small patch of snow can greatly inhibit the PV harvest.

If you have some "guts"  AND you have proper fusing in your system, you can briefly Jumper around the Charge controller
 You should be able to read the PV voltage, which should be a fair amount higher than your battery voltage.

 connect the PV input ( from the panels) directly to the battery connection.   You will get sparks - or you can trun your combiner box off, make the jumper connection, and switch the combiner back on.
  You SHOULD see the PV voltage drop to the battery voltage, and then the battery voltage should slowly start to rise over a period of time.

And maybe I'm not being clear on how to do this test, someone else might speak up.
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Classic 200| 2Kw PV, 160Voc | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph )| Listeroid 6/1, st5 gen head | XW6048 inverter/chgr | midnight ePanel & 4 SPDs | 48V, 800A NiFe battery bank | MS-TS-MPPT60 w/3Kw PV

ClassicCrazy

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Re: Problems since winter storm
« Reply #2 on: February 20, 2021, 02:08:27 PM »
Hi guys. I need help figuring out what is going on with my off-grid system.  It was working fine before this recent winter storm. 

I just returned to the cabin from spending a week in town to escape the frigid temps.  I cleaned the snow off the panels but found I'm not producing much energy at all despite a gorgeously sunny day.  I should be seeing 20A ointo my battery bank right now but I am only seeing 0.5 to 1A and the KID is switching between "Resting" and "BulkMPPT" modes frequently.  Could I simply be having a moisture issue with one of the connections at the panels?
I would try shutting off power from PV, then shut off power to Kid to let it reset. Then power Kid back up and then PV and see what it is doing.

Larry
system one
Classic 150 , 5s4p  Kyocera 135watt , 12s Soneil 2v 540amp lead crystal for 24v pack , Outback 3524 inverter
system two
Classic 150 ,5s 135 watt Kyocero , 16s Calb 100AH LiFePO4 , Outback VFX 3648 inverter
system three
Midnite KID MPPT 24 DC in to  12 volt AGM batterie

qrper

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Re: Problems since winter storm
« Reply #3 on: February 20, 2021, 02:58:06 PM »
Just for grins, if you have a combiner box, I'd check the fuses/breakers. If you had a burst of sun, and with the panels winter weather cold, you could have popped a breaker or two.

mike
System one: 7kWp w/ Trina 250 W panels @90 Vdc. Classic 150 to 16-6 V U.S batteries. Trace 5548 sine wave inverter.
System two: 6kWp grid tie with solaredge inverter.
System three: Midnite Brat, two 120 W Astropower modules, 100 Ah battery. Runs the LED streetlight in the back yard.

boB

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Re: Problems since winter storm
« Reply #4 on: February 20, 2021, 04:30:36 PM »

What is your battery voltage and then, what is your PV input voltage during RESTING and what is the PV voltage when it says BULK ?

Two important questions.
K7IQ

Tobit

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Re: Problems since winter storm
« Reply #5 on: February 20, 2021, 04:42:16 PM »
Bob, sun is going down.  Right now battery is at 12V, PV is at 22V.

boB

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Re: Problems since winter storm
« Reply #6 on: February 20, 2021, 05:29:10 PM »
Bob, sun is going down.  Right now battery is at 12V, PV is at 22V.

OK, need to get those two (2) input voltage PV numbers which will tell a lot

Maybe tomorrow
K7IQ

Tobit

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Re: Problems since winter storm
« Reply #7 on: February 21, 2021, 10:46:11 AM »
Bob, sun is going down.  Right now battery is at 12V, PV is at 22V.

OK, need to get those two (2) input voltage PV numbers which will tell a lot

Maybe tomorrow

Bob, this morning:

RESTING: 22V
BULK: 19.3V

boB

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Re: Problems since winter storm
« Reply #8 on: February 21, 2021, 04:11:47 PM »

Bob, this morning:

RESTING: 22V
BULK: 19.3V

Thanks Tobit...

OK, so this is good.   I think.

I have a feeling that this 19.3 volts could be a wee bit lower. 

I can't remember but isn't there a choice of tracking modes on the Kid controller ?  If so, try changing it from SOLAR mode to LEGACY or P&O mode and see if that helps.    The Vmp or maximum power point voltage for 22 Volts Voc should be a bit lower than 19.3V...  Say, somewhere around 17.6 V or so.

Might not be the issue but I would take a look.

boB
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Vic

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Re: Problems since winter storm
« Reply #9 on: February 21, 2021, 09:00:00 PM »
Hi Tobit,

How did you do today?   Any more power production?

It was suggested that you try Rebooting the KID.   Assume that you did that.

Later,  Thanks,   73  GL   Vic
Off Grid - Two systems -- 4 SW+ 5548s, Surrette 4KS25 1280 AH X2@48V, 11.1 KW STC PV, 3X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  Thanks MN for Great Products/Service/Support!

Tobit

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Re: Problems since winter storm
« Reply #10 on: February 22, 2021, 11:00:18 AM »
Hi Tobit,

How did you do today?   Any more power production?
Harvesting more today at 10am than the past two days combined.  I guess the panels were just not getting the sun I thought.

boB

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Re: Problems since winter storm
« Reply #11 on: February 22, 2021, 11:33:28 AM »
Hi Tobit,

How did you do today?   Any more power production?
Harvesting more today at 10am than the past two days combined.  I guess the panels were just not getting the sun I thought.

If the panels weren't getting as much sun on them, that would also account for the higher Vmp max power voltage of 19.3 volts.

The PV input voltage should be a bit lower then if you are getting more sun on them and maybe also if it is warmer.



K7IQ

Tobit

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Re: Problems since winter storm
« Reply #12 on: February 22, 2021, 12:22:02 PM »
The PV input voltage should be a bit lower then if you are getting more sun on them and maybe also if it is warmer.
Yes, PV input during bulk has dropped to 17.1V.  Thanks

Vic

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Re: Problems since winter storm
« Reply #13 on: February 22, 2021, 01:16:10 PM »
Tobit,   sounds encouraging.   73   GL,   Vic
Off Grid - Two systems -- 4 SW+ 5548s, Surrette 4KS25 1280 AH X2@48V, 11.1 KW STC PV, 3X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  Thanks MN for Great Products/Service/Support!

boB

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Re: Problems since winter storm
« Reply #14 on: February 22, 2021, 07:33:08 PM »

Yes, PV input during bulk has dropped to 17.1V.  Thanks


Excellent !

This is useful as kind of a "sanity check" to look at the Vmp  and the Voc

Typically we say that the Vmp should be somewhere around 80%  of the Voc reading for a PV array that is in full sun or not partially shaded with mostly sun or maybe some clouds.  (no poles or chimney partially shading the panels)

In your case today, that ratio is about  17.1/22  or almost 78% which is in range.  If the Voc is lower today because maybe it is warmer and more sun on the panels, that is probably more like 80%

I see anything between say, 76% and 82% or so but thought something must be off with a ratio of 86% from yesterday.

Glad it is working better today !

boB
K7IQ