haycord
New Member
I don't understand - when yall are talking about 'max production' isn't that dependent on CC Output Limit and/or the active Load?
Charge Controller PV Input Limits
- Thread starter haycord
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timselectric
If I can do it, you can do it.
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- Feb 5, 2022
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Yes
It's dependent on output and input limits.
And the loads connected.
For instance, my SCC can input a maximum of 18a, and output a maximum of 100a @ 48v nominal. Both limits will never be exceeded by the SCC.
When I say maximum production, I'm referring to the 18a limit.
Wattage is dependent on the voltage, when the amperage is at maximum.
haycord
New Member
Very good, thanks.
haycord
New Member
FYI Update: I contacted Rich Support about their 40A MPPT and asked if I could exceed the stated 1100W max PV input and connect 1400W. They said no problem - the SCC will not draw more power than is needed to meet the 40A output rating. Exactly as many of you said. Obviously the Voc is a hard limit. Thanks again for everyone's help.
ddxv
New Member
I've also been asking on Midnite forums about it, and user boB there said something similar for exceeding PV input for the Classics:
CleverTomato
New Member
I have a similar question/feeling/uncertainty.... Inherited an established system with the property. 6 x 310W ET panels and placed in a terrible spot for light. Renogy 60A mppt charge controller never operated to/at max/full potential.
Moved panels to a new place with significantly better sun and get a new double fast flash on the charge controller. Indicates that it is charging battery at the rated current but on the display watts and amps are 'over' what the manual says is max. Do I understand that this is the charge controller doing what it is designed to do and controlling. I don't want to burn it up.
5 panels in full sun keeps everything within limits. but it only takes one cloud.
Working under the assumption all wires are proper sizes, that all fuses are in and where they need to be...batteries are in good health and wired correctly. etc...that everything is set for optimal performance of the system... Am I going to cook my charge controller with an 'oversized' array or is it simply doing what it is designed to do?
If it is just doing what it does... I have 5 more 100W panels I would like to attach...when it gets cloudy in TN...it can last for days.
Moved panels to a new place with significantly better sun and get a new double fast flash on the charge controller. Indicates that it is charging battery at the rated current but on the display watts and amps are 'over' what the manual says is max. Do I understand that this is the charge controller doing what it is designed to do and controlling. I don't want to burn it up.
5 panels in full sun keeps everything within limits. but it only takes one cloud.
Working under the assumption all wires are proper sizes, that all fuses are in and where they need to be...batteries are in good health and wired correctly. etc...that everything is set for optimal performance of the system... Am I going to cook my charge controller with an 'oversized' array or is it simply doing what it is designed to do?
If it is just doing what it does... I have 5 more 100W panels I would like to attach...when it gets cloudy in TN...it can last for days.
sunshine_eggo
Happy Breffast!
What controller? MPPT or PWM. If PWM, they generally can't regulate their current and shouldn't be over-paneled.
If it's a 60A MPPT, and it's reporting a little over 60A, I would call that error - error in actual output (nothing is perfectly calibrated) and/or error in measurement.
It is a Renogy. It's best to keep expectations low.
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So I'm also curious about this for sizing my arrays below is the spec sheet.
I'm looking at 550W panels but they have the below specs:
Vmp=41V
Voc=49.85V
Imp=13.42A
Isc=14.12A
From what I'm understanding I shouldn't worry about the amperage unless accidentally connecting reverse polarity, how many panels would you suggest per string if I was looking at using possibly 300ft PV1-F6 /10awg
I'm looking at 550W panels but they have the below specs:
Vmp=41V
Voc=49.85V
Imp=13.42A
Isc=14.12A
From what I'm understanding I shouldn't worry about the amperage unless accidentally connecting reverse polarity, how many panels would you suggest per string if I was looking at using possibly 300ft PV1-F6 /10awg
sunshine_eggo
Happy Breffast!
I can say that statement is true for Victron MPPT, but I've never seen it definitively defined for the MPPT for high voltage AiO. You could assume that it's correct, but I don't know that I would.
The limits are pretty clear on that unit. Anything over 13A is wasted, and they recommend nothing more than 17A Isc on a string. The panels have 13.42A Imp (already slightly derating the panels) and 14.12A Imp (under 17A)
The terminology is a little confusing, but that unit has two MPPT trackers with 1 string per tracker.
I wouldn't put more than 8S on each MPPT unless you're in a climate that NEVER gets below freezing. If it never gets below freezing, 9S. No parallelling on either MPPT.
I'll do some more checking/praying someone can give an answer.
It's becoming harder to find lower Imp panels here without spending alot more per W these at 13.42A are the closest to sweet spot I could find anything lower and I'm paying the same price for a 370W as I would for a 550W.
I know you love Chinese AiO`s and their manuals
I was thinking either 6 or 8 depending on whether I go ground mount which would be 300ft away or add a raised pergola above the power shed/inverters not worried about freezing it rarely drops below hot as hell here.
sunshine_eggo
Happy Breffast!
Based on the input of SS and EG4 people on this site, those Isc limits are relatively important -"damage may result" - but that could just be the reverse polarity contactor.
I meant to indicate that's about as perfect as you can get. Given that PV rarely outputs max current, even a little more would be fine.
Heh. I've read enough of them to not be so confused anymore. I just needed to parse it out.
Yeah, I figured it was tropical-ish at least. Above freezing, up to 9S (-2°C); below freezing up to 8S (-30°C) . Given the long run, I would shoot for 9S.
LakeHouse
Solar Enthusiast
On an inherited system, I would not make this assumption.
CleverTomato
New Member
My manual math and limit definitions say 720W 60A. It is a Renogy 60A MPPT charge controller and the aformention 310W ET panels.
The attached image is a good sun day with 5 panels. See image:
6 panels on a good sun day can go to 775 to 800W with 60 amps +/- 10ish...even with 6 panels it doesnt take much cloud to change things.
Im wondering is this the charge controller doing what it is supposed to do or do am I going to melt the thing to the wall. With good sun it can be like that for a number of hours. At this point I have just been using the 5 panels and typically perfectly acceptable mornings, evenings and cloudy days I notice a difference.... Simply. Dont want to go out and hook up other panel on cloudy days (not difficult but not ideal) or am I good to hook it up and just let it do what it do!!!
All of you have been awesome with your imput!
The attached image is a good sun day with 5 panels. See image:
6 panels on a good sun day can go to 775 to 800W with 60 amps +/- 10ish...even with 6 panels it doesnt take much cloud to change things.
Im wondering is this the charge controller doing what it is supposed to do or do am I going to melt the thing to the wall. With good sun it can be like that for a number of hours. At this point I have just been using the 5 panels and typically perfectly acceptable mornings, evenings and cloudy days I notice a difference.... Simply. Dont want to go out and hook up other panel on cloudy days (not difficult but not ideal) or am I good to hook it up and just let it do what it do!!!
All of you have been awesome with your imput!
Attachments
sunshine_eggo
Happy Breffast!
Have you verified the current readings with a clamp DC ammeter?
pollenface
Solar Wizard
I have a victron 100/20 in my shed with 1.5kw attached for my 48v setup, I've changed to a 12v battery for fun, so at 12v it is 517% overpanelled.
No issues, just output limited to 290w.
No issues, just output limited to 290w.
CleverTomato
New Member
I did at four panels. I have not. That is the appropriate thing to do. I think the heart of what I am wanting to know is: is the charge controller really there to manage that? and can it? I know I can get another controller for a reasonable price that will perform perfectly acceptably and just put two panels on it. Just am trying to keep it to one thing to monitor.
Thanks for the encouragement to just do the steps. If the numbers were over...I would still have the same question.
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