Author Topic: Quick newbie question about Classic 200SL  (Read 601 times)

justinbowser

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Quick newbie question about Classic 200SL
« on: June 07, 2019, 06:44:08 PM »
I currently have 900 watts of PV panels, a "generic" 60 amp MPPT controller, and a 300 Ah 24V battery bank at our cabin.  Works good but hoping to beef it up so I might be able to run AC during the heat of the day so I will be paralleling an additional array and CC on my current battery bank.

I have bought 9 Mission Solar 310 W panels and a Classic 200SL and later realized that I will be exceeding the specs of the CC.  The solar supply house said I could run all of the panels on it without a problem but I would occasionally experience clipping.  I can deal with that until my battery bank dies and I upgrade to 48V.

Will I cause any damage to the CC by exceeding the max recommended wattage?

bee88man

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Re: Quick newbie question about Classic 200SL
« Reply #1 on: June 07, 2019, 09:14:04 PM »
If the "clipping threshold doesn't exceed the current limit all is good.

A little bit of "clipping" is a "good thing"...you'll still get more production in overcast or cloudy weather than if there were never any clipping at all on the best PV days...

justinbowser

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Re: Quick newbie question about Classic 200SL
« Reply #2 on: June 07, 2019, 11:34:41 PM »
If the "clipping threshold doesn't exceed the current limit all is good.

How do I determine that?

mike90045

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Re: Quick newbie question about Classic 200SL
« Reply #3 on: June 08, 2019, 12:10:00 AM »
310w  x 9 panels.
  How are you going to wire the panels. 3S3P ?   What is the Voc for those panels ?

any way you slice it, it's 2790 watts  at  27V pushing 103A.   That's a pretty heavy amount of over-panel for a 24V bank

http://tinyurl.com/LMR-Solar

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

justinbowser

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Re: Quick newbie question about Classic 200SL
« Reply #4 on: June 08, 2019, 09:28:08 AM »
I realize that it is a bit of overkill right now but my concern is if the CC would be damaged.  My goal is to be able to run a small air conditioner during the day without having to run the generator all the time.  As mentioned after my current battery bank dies I will be switching to a 48V system but that is probably a year down the road.  I can always cut back to two strings of four or even 2 strings of 3 if I have to.

Vic

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Re: Quick newbie question about Classic 200SL
« Reply #5 on: June 08, 2019, 07:57:05 PM »
If the "clipping threshold doesn't exceed the current limit all is good.

How do I determine that?

Hi Justin,

Use the Classic String Sizing Tool in the following Link.   Enter all the info on the input page,   and follow the recommendations from the  output result.

Generally,   it is best to not use PV configurations that show as "Excessive"  on the Sizer's output.

One thing that over-PVing MPPT Charge Controllers  (CCs),   like the Classic and many others,   is that when in Abosrb, EQ  and Float  the extra PV input power often can result in higher input voltage to the CC (due to lighter loading of the PVs,   in these modes).   The rise in Vin will result in additional heating of the CC,   which is generally not that desirable.

FWIW,   IMO,    Vic
« Last Edit: June 08, 2019, 08:04:03 PM by 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!

justinbowser

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Re: Quick newbie question about Classic 200SL
« Reply #6 on: June 08, 2019, 09:28:06 PM »
Guess I'll just do six panels until I switch to 48V...

Vic

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Re: Quick newbie question about Classic 200SL
« Reply #7 on: June 09, 2019, 04:13:57 PM »
Hi Justin,

Assume that you ran 9X,  vs 6X 310s through the MN Sizer.

What I said about Excessive at the bottom of the sizer's output was not quite correct.

When the word,  "EXCESSIVE"  is in Red,   would suggest not using that configuration for a long period of time.

Attached is the SIzer output,   in case you did not run it yet,   or for others.   The outdoor temperatures are probably not correct for your location.

Good Luck,   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!