Meanwhile, I have 9 * 260W panels connected to my 45A Morningstar CC. I never saw current of over 25A on the CC. The panels are rated 8.1A.
Connection is 3 in series then 3 strings paralleled. My thoughts were that with the 3 strings in parallel, the max current would be 24A (8.1*3).
Which means i can still comfortably add additional string of 3 panels to make it 4 strings in parallel (12 panels in all. which is 32A).

I made the connection, but the moment i plugged in the fuses, the CC sparked and smoked!!! I had unplug the fuse with speed of light. I cross checked the connections, measured the voltage from the new stings and polarities and it looked all OK.
I then went to the CC manual then noticed the max power for 45A is 2500W. Hmmm....
With my 9 panels I obviously had 9 * 260W = 2340W. But with the 12 panels, its 3120W. I was convinced the CC is maxed out.
Luckily the CC operated fine after the smoking (that's after I disconnect the new panels)

But I was sharing this with someone and he thought the CC can accommodate my additional 3 panels as they all combined has not reached the 45A Maximum rating. He thought I may have had a wrong connection (I doubt though).

Can the profs in the house help me analyze please. All panels are poly

kiekie1:


40a mppt 12/24/48v @ 80k

Thanks Boss. Will revert

pdozie:
Meanwhile, I have 9 * 260W panels connected to my 45A Morningstar CC. I never saw current of over 25A on the CC. The panels are rated 8.1A.
Connection is 3 in series then 3 strings paralleled. My thoughts were that with the 3 strings in parallel, the max current would be 24A (8.1*3).
Which means i can still comfortably add additional string of 3 panels to make it 4 strings in parallel (12 panels in all. which is 32A).

I made the connection, but the moment i plugged in the fuses, the CC sparked and smoked!!! I had unplug the fuse with speed of light. I cross checked the connections, measured the voltage from the new stings and polarities and it looked all OK.
I then went to the CC manual then noticed the max power for 45A is 2500W. Hmmm....
With my 9 panels I obviously had 9 * 260W = 2340W. But with the 12 panels, its 3120W. I was convinced the CC is maxed out.
Luckily the CC operated fine after the smoking (that's after I disconnect the new panels)

But I was sharing this with someone and he thought the CC can accommodate my additional 3 panels as they all combined has not reached the 45A Maximum rating. He thought I may have had a wrong connection (I doubt though).

Can the profs in the house help me analyze please. All panels are poly

Your CC has two sections, the input and the output sections.

The input section is that part that you connected to the solar panel while the output section is the part connected to the battery.

You are looking at the maximum current on the input section which is usually lower than the current in the output section. A MPPT controller will step down the voltage from the panel to match the battery and increase the current proportionally in accordance to the laws of conservation of energy.

In your case, maximum power available is 9*260W=2340W

The MPPT voltage of your panel is 260/8.1=32V

3 panels in series will then give 32.1*3=96.3V

3 panels in parallel will give 8.1*3=24.3A

So, in the input section the MPPT parameters are: 96.3V, 24.3A, 2340W

Now lets look at the output section.

If you have a 12V battery setup, the in-coming 96.3V gets stepped down to 12V and the 24.3A current will be increased proportionally. So the output current will be 24.3*96.3/12=195A. So require a CC that can handle 200A

If you have a 24V battery setup the in-coming 96.3V gets stepped down to 24V and the 24.3A current will be increased proportionally. So the output current will be 24.3*96.3/24=97.5A So require a CC that can handle 100A

If you have a 48V battery setup the in-coming 96.3V gets stepped down to 48V and the 24.3A current will be increased proportionally. So the output current will be 24.3*96.3/48=48.8A So require a CC that can handle 50A.

Adding another string of 3*260w panels to the setup will increase the power to 3,120W, hereby pushing up the CC requirement by 33%. This will exceed the capacity of a 45A CC even at 48V nominal battery. Hence the smoke.

The CC did not smoke earlier because of inherent power losses and conversion inefficiency that will not allow the panels and CC to operate at 100% efficiency.

dapsyra:


Your CC has two sections, the input and the output sections.

The input section is that part that you connected to the solar panel while the output section is the part connected to the battery.

You are looking at the maximum current on the input section which is usually lower than the current in the output section. A MPPT controller will step down the voltage from the panel to match the battery and increase the current proportionally in accordance to the laws of conservation of energy.

In your case, maximum power available is 9*260W=2340W

The MPPT voltage of your panel is 260/8.1=32V

3 panels in series will then give 32.1*3=96.3V

3 panels in parallel will give 8.1*3=24.3A

So, in the input section the MPPT parameters are: 96.3V, 24.3A, 2340W

Now lets look at the output section.

If you have a 12V battery setup, the in-coming 96.3V gets stepped down to 12V and the 24.3A current will be increased proportionally. So the output current will be 24.3*96.3/12=195A. So require a CC that can handle 200A

If you have a 24V battery setup the in-coming 96.3V gets stepped down to 24V and the 24.3A current will be increased proportionally. So the output current will be 24.3*96.3/24=97.5A So require a CC that can handle 100A

If you have a 48V battery setup the in-coming 96.3V gets stepped down to 48V and the 24.3A current will be increased proportionally. So the output current will be 24.3*96.3/48=48.8A So require a CC that can handle 50A.

Adding another string of 3*260w panels to the setup will increase the power to 3,120W, hereby pushing up the CC requirement by 33%. This will exceed the capacity of a 45A CC even at 48V nominal battery. Hence the smoke.

The CC did not smoke earlier because of inherent power losses and conversion inefficiency that will not allow the panels and CC to operate at 100% efficiency.

please note, he has never seen 25a on the said 260w*9 on 48v system

JUO:
please note, he has never seen 25a on the said 260w*9 on 48v system

JUO:
please note, he has never seen 25a on the said 260w*9 on 48v system

It depends on where he is looking.

On the input side, based of his 3x3 arrangement, he will never see 25A. The highest he will probably see is about 20A.

But on the output side, at peak periods, he will see values above 40A.

dapsyra:


It depends on where he is looking.

On the input side, based of his 3x3 arrangement, he will never see 25A. The highest he will probably see is about 20A.

But on the output side, at peak periods, he will see values above 40A.

I believe he meant output bro. but he can clarify

Am not sure if Morningstar displays incoming and outgoing values.
The figures I quoted are what is displayed, it doesn't indicate if it's IN or OUT.
Presently this is what the CC reads

1134W
3760WH
52V
21.2A

pdozie:
Am not sure if Morningstar displays incoming and outgoing values.
The figures I quoted are what is displayed, it doesn't indicate if it's IN or OUT.
Presently this is what the CC reads

1134W
3760WH
52V
21.2A

@dapsyra the 25a is output

pdozie:
Am not sure if Morningstar displays incoming and outgoing values.
The figures I quoted are what is displayed, it doesn't indicate if it's IN or OUT.
Presently this is what the CC reads

1134W
3760WH
52V
21.2A

So, the figures are for the output of the CC.

If you have never seen above 25A output from the CC going into your 48V battery from 2,340W (9*260w) array, then something is not optimal.

Either there is an issue with the panel installation/cabling or your overnight usage is so small that your CC is throttling down in order not to overcharge the batteries.

Pls i want to ask,

Inverter system-24v

Battery-200Ah

Total load-500W

Assuming my panels are 250w
Vm-30.6v
Voc-37.4v
Isc-8.92A
Im-8.17A

My CC is

Atracer 100v 40A
1040w Max rated power
3120w Max array power

1.what is the maximum number of panels I can get

2.what will be the best array configuration ?

3. What will be the charging output current to my battery

4.Please how does this whole setup work?

a.During the day, my load gets supply directly from the CC

b.Gets supply from the battery, then it's replenished from the CC as it's being used

Thanks, I await answers, i'm also aware that these questions must have been previously answered.

I have gone through all the post, it is still not clear to me

CC
JUO
Bigrovar
Dmerciful

dapsyra:

If you have a 24V battery setup the in-coming 96.3V gets stepped down to 24V and the 24.3A current will be increased proportionally. So the output current will be 24.3*96.3/24=97.5A So require a CC that can handle 100A

Pls how is this possible? Most of the CC advertised here or reffered to are usually maxed at 80A,

Am I missing something?


Can you elaborate more using the parameters I gave in my earlier post

Thanks

dapsyra:


So, the figures are for the output of the CC.

If you have never seen above 25A output from the CC going into your 48V battery from 2,340W (9*260w) array, then something is not optimal.

Either there is an issue with the panel installation/cabling or your overnight usage is so small that your CC is throttling down in order not to overcharge the batteries.

I do know that Current (A) is an instantaneous figure. That means I must be glued to the CC to get the exact reading. Its possible it has exceeded the 25A while I wasn't watching or maybe not. Below though are other readings from logged data in the CC. Would it help to determine if the system is optimal or not?

You seem very calibrated on the right parameters....impressive. See my response below. Buzz me if u need further response(08035415969)

nannymcphee:
Pls i want to ask,

Inverter system-24v

Battery-200Ah

Total load-500W

Assuming my panels are 250w
Vm-30.6v
Voc-37.4v
Isc-8.92A
Im-8.17A

My CC is

Atracer 100v 40A
1040w Max rated power
3120w Max array power

1.what is the maximum number of panels I can get-recommended 1000w[b][/b]

2.what will be the best array configuration ? 2*2

3. What will be the charging output current to my battery?~[b]0A-33A[/[/b]font]

4.Please how does this whole setup work?[font=Lucida Sans Unicode] Not clear on the question

a.During the day, my load gets supply directly from the CC, Nope, loads gets supply from d battery tru d inverter however the panels can harvest more to the batteries than is being expended so that net it would suffice to say that d solar panels are powering d loads directly.

b.Gets supply from the battery, then it's replenished from the CC as it's being used-yes, gets supply from battery but being replenished sometimes more than consumption.

Thanks, I await answers, i'm also aware that these questions must have been previously answered.

I have gone through all the post, it is still not clear to me

CC
JUO
Bigrovar
Dmerciful

@Dmerciful

Don't know why i can't quote, According to you

1.Recommended panels-1000w

2.Array config-2×2

3.Charge current to batteries 0-33A

A.Pls can you show the calculations you used in arriving at No 2 & 3

B.if my battery spec sheet says Max charge current 25A, how then do i regulate the CC not to supply more than this? 33A is in excess

C.Pls what's the difference between max rated power & max array power

D.In the morning, at what point will i know that my panels are producing enough "juice" to power my loads, what parameter will i be looking at on the CC

I ask the above cos some folks will say they put on their fridge btw 11am-4pm

Why 11am? Why put off at 4pm? What parameters informed them to turn on & off the fridge at that time?

Thanks Sire

nannymcphee:
@Dmerciful

Don't know why i can't quote, According to you

1.Recommended panels-1000w

2.Array config-2×2

3.Charge current to batteries 0-33A

A.Pls can you show the calculations you used in arriving at No 2 & 3

B.if my battery spec sheet says Max charge current 25A, how then do i regulate the CC not to supply more than this? 33A is in excess

C.Pls what's the difference between max rated power & max array power

D.In the morning, at what point will i know that my panels are producing enough "juice" to power my loads, what parameter will i be looking at on the CC

I ask the above cos some folks will say they put on their fridge btw 11am-4pm

Why 11am? Why put off at 4pm? What parameters informed them to turn on & off the fridge at that time?

Thanks Sire

I believe your husband is using your id to type this for quick attention. Cos the person typing this is well knowledgeable for advise

Buzz me offline pls.

nannymcphee:
@Dmerciful

Don't know why i can't quote, According to you

1.Recommended panels-1000w

2.Array config-2×2

3.Charge current to batteries 0-33A

A.Pls can you show the calculations you used in arriving at No 2 & 3

B.if my battery spec sheet says Max charge current 25A, how then do i regulate the CC not to supply more than this? 33A is in excess

C.Pls what's the difference between max rated power & max array power

D.In the morning, at what point will i know that my panels are producing enough "juice" to power my loads, what parameter will i be looking at on the CC

I ask the above cos some folks will say they put on their fridge btw 11am-4pm

Why 11am? Why put off at 4pm? What parameters informed them to turn on & off the fridge at that time?

Thanks Sire

pdozie:


I do know that Current (A) is an instantaneous figure. That means I must be glued to the CC to get the exact reading. Its possible it has exceeded the 25A while I wasn't watching or maybe not. Below though are other readings from logged data in the CC. Would it help to determine if the system is optimal or not?

What is your low battery cut off voltage set as?

nannymcphee:
Pls i want to ask,

Inverter system-24v

Battery-200Ah

Total load-500W

Assuming my panels are 250w
Vm-30.6v
Voc-37.4v
Isc-8.92A
Im-8.17A

My CC is

Atracer 100v 40A
1040w Max rated power
3120w Max array power

1.what is the maximum number of panels I can get

2.what will be the best array configuration ?

3. What will be the charging output current to my battery

4.Please how does this whole setup work?

a.During the day, my load gets supply directly from the CC

b.Gets supply from the battery, then it's replenished from the CC as it's being used

Thanks, I await answers, i'm also aware that these questions must have been previously answered.

I have gone through all the post, it is still not clear to me

CC
JUO
Bigrovar
Dmerciful

Your load figure should include how many hours of the day you intend to run that load. running 500w load on a 24v battery system would lead your battery to an early grave (especially when run at night) The recommended discharge rate for a 200ah battery rated at c20 is 240w (500w discharge rate is more than twice that) discharging your c20 batteries at that rate means it is effectively no longer a 200ah battery but a 150 - 100ah battery depending on the peukert rating of the battery. even if the battery is rated c10 500w is still higher than recommended discharge which in your case is 480w.

You should not that most batteries in the market with (exception of makers like trojan, us batteries and some other top battery makers) most batteries out there have exaggerated capacity. I usually assume the actual capacity of most 200ah batteries in Nigerian market are actually 150ah - 180ah and factor that when determining rate and depth of discharge.

It is important you clearly state your load in terms of total load in watt and watt hours. both are very different and also very important factor in design of an optimal setup.

DUNKA:
What is your low battery cut off voltage set as?

I don't have any settings for it. The inverter beeps once the voltage drops to 41v and below

chris81964:


First number is immediate production from your panels
Second number is total production from when the controller woke up that day
Third is your battery voltage
Fourth is the current being pumped into your batteries
When you provided the data was your battery bank in bulk absorb or float? In bulk it is putting maximum current, in absorb it is maintaining voltage so current could be lower depending on what else is going on. In float just enough current to keep that batteries topped up.
Watts = volts X amps. Amps is also current

Hi Chris,
I didn't take not of the state. I will check the readings again at various times today and note the states as well - whether bulk or absorb or float

Kind regards

Seems 'she' is an installer

JUO:
I believe your husband is using your id to type this for quick attention. Cos the person typing this is well knowledgeable for advise

pdozie:


I don't have any settings for it. The inverter beeps once the voltage drops to 41v and below

Allowing your 48V battery bank deplete to 41V which represent 100% DOD before cutoff will send your batteries to an early grave.

DMerciful:
Seems 'she' is an installer

Lol, I'm not an installer

I have a B.eng in Electrical/Electronics engineering though I don't practice.

I also try as much as possible not to give any pointers as to my real life personality.

So I will appreciate answers, besides others can learn from it too

As for JUO, No I'm not married, neither am I avaliable

dapsyra:


So, the figures are for the output of the CC.

If you have never seen above 25A output from the CC going into your 48V battery from 2,340W (9*260w) array, then something is not optimal.

Either there is an issue with the panel installation/cabling or your overnight usage is so small that your CC is throttling down in order not to overcharge the batteries.

I strongly suspect the panel position/angles are not optimal. Seemingly common. Cable size and length are just as culpable.

DMerciful:
Seems 'she' is an installer

really?

pdozie:


I don't have any settings for it. The inverter beeps once the voltage drops to 41v and below

Your batteries are heading for an early grave. Urgently set your lbco voltage to between 46 to 48 volts if not you will be back here to report that your batteries have started to fail.

dapsyra:


Allowing your 48V battery bank deplete to 41V which represent 100% DOD before cutoff will send your batteries to an early grave.

gbam

DUNKA:
Your batteries are heading for an early grave. Urgently set your lbco voltage to between 46 to 48 volts if not you will be back here to report that your batteries have started to fail.

44v - 48v is still OK ... It all depends on his loads and battery bank size. Thanks !

nannymcphee:
@Dmerciful

Don't know why i can't quote, According to you

1.Recommended panels-1000w

2.Array config-2×2

3.Charge current to batteries 0-33A

A.Pls can you show the calculations you used in arriving at No 2 & 3

B.if my battery spec sheet says Max charge current 25A, how then do i regulate the CC not to supply more than this? 33A is in excess

C.Pls what's the difference between max rated power & max array power

D.In the morning, at what point will i know that my panels are producing enough "juice" to power my loads, what parameter will i be looking at on the CC

I ask the above cos some folks will say they put on their fridge btw 11am-4pm

Why 11am? Why put off at 4pm? What parameters informed them to turn on & off the fridge at that time?

Thanks Sire

Let us see some pix of ur installation and Cc reading.
Location
AWG of ur cable, ba3 type, inverter type etc.
Renewable is rewarding but come clean for advice