Used Solar Panels from Santan Solar--Only 41% of the Rated Power?

MWeiss

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Apr 22, 2020
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I had a peak of 63 amps from the southeast facing array this morning. There's a high albedo due to white puffy clouds around the sun. It only lasted for seconds and then the current went back down to around half that.

Does anyone know of a dealer that's got the Growatt SC4880 in stock for around $269 each?
 

MWeiss

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Apr 22, 2020
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I called Signature Solar and they are out of stock on the solar charge controllers. They also have no restock date.
Sango Solar has them for $299, but when I tried to order just now, their website timed out.
Any other dealers carry SC4880?

Alibaba has it, only problem 45 days deliver: https://www.alibaba.com/product-detail/Super-Solar-Growatt-SC-4880-MPPT_1600260169433.html

Zeb Solar has them for $410 each, but shipping from TN to CT is $500!
 
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iamrich

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Dec 17, 2020
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Elgin, Texas
Random Google search:

 

MWeiss

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Random Google search:

The site let me place an order. Oddly, only payment option was cash on delivery. Hopefully they will actually ship. Thanks for finding that. My search results did not include that site.
 

MWeiss

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Apr 22, 2020
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I tried e-mailing them, but have not yet gotten a reply. I read their "about us" section and they seem like a small operation, guy moved from FL to TN and is selling solar stuff. I may try calling when I get back to the office later.

UPDATE: called them and found out their website provider screwed them over with a non functional website. The lady is going to check if she has the 4880s in stock when she returns home. She mentioned an older model MPPT that she has, but no specifics..

UPDATE 2: She doesn't have them in stock.
I went over to Signature Solar and called them again. This time the SC4880 is available as preorder. I called and they expect shipment in July. That's probably my best bet so I ordered two units.
 
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MWeiss

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This diagram really illustrates the advantage of MPPT controllers. This jives nicely with the fact that I'm only harvesting about 3500W from 9600W of panels without the controller. In the example, the PWM harvests only 100W from a 250W panel. The MPPT harvests the full 250W.

So I may not need more panels. I need a charge controller. I've two on order, but will have to wait a month. Meanwhile, we have to keep switching to grid power, every other day as the a/c puts an extra burden on the system.

1656209626183.png
 

MWeiss

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Apr 22, 2020
Messages
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Bought a clamp on ammeter this week and used it to check the ten series strings in the array that was low on output and made a couple of interesting discoveries.
One was that one of the series strings had no current. The rest ranged from 2.7 to 3.3A. This string was dead. Zero. Popped the lid on the junction box and it was all corroded inside! Used panel from Santan Solar. While testing individual panels I used a 2 ohm 100W resistive dummy load. While testing individual strings, I was getting over 7A of current. But when I connected back to the system which goes directly to the batteries, the amperage was less than half. I now realize that this is operating far below MPP.
I have two Growatt SC4880 charge controllers on order with Signature Solar. They are backordered and estimate to be a month out, so I'll have to limp along for another month. Running 2S 5P for each of 2 arrays, there's not a lot of open circuit voltage, so when it's cloudy, total solar output drops from 4kW to 200W on rainy days. I think wiring them 5S 4P for 185V open circuit will help a lot on cloudy days with the MPPT controller. Presently, I get good power for 3-4 hours around high noon. I hope the controllers arrive soon! Going to need air conditioning!
 
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