I have 9 panels 220w 40.0v in 3 sets of 3. Creating 660w 120v my 150/70 says it is pulling in 1400w . Is this what it’s supposed to be?
Hi @Jackjax76
so you have a 3p3s PV array that is supposed to deliver 1,980 Wp, but you get 1,400 W.
What is your system voltage?
24V would limit to 1,700W.
Are all panels having same direction?
What are azimut and elevation?
What does PV GiS predict or forecast.solar?
What is the location?
What is the weather?
Is there any shadow, maybe a small antenna?
How old are the panels?
On cold (8C) sunny April days my new 425Wp Vertex S+ delivered 500W. Now at 18C, they produce 420W m. I gave 2p2s on a MPPT 150/45 @48V getting out 2,050W one day.
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I have three strings of three in series taking it to 120v 5.5a 220w there is three sets I parallel together making it a 120v. 16.5a 660w system. But my 150/ 70 says it is pulling in over 1400w. It’s a friend’s system I’m trouble shooting but he needs to here it from a pro .what do you think.
Joaquin Valdez
@Jackjax76
Your math is not correct here.
9 panels x 220w is 1980 watts installed.
@BjoernK is correct.
This is working fine. It is possibly installation and irradiation conditions keeping it there.below the installed amount
3 panels in series makes it a 120v 5.5a 220w string.
Then I made 2 more strings the same way.
That leaves us with
String #1 120v 5.5a 220w series
String #2 120v 5.5a 220w series
String #3 120v 5.5a 220w series .
All positive cables equating three lines to a mp3 container than the same with the neutral three lines to a mp3 the parallel connection adds the amp and watts leaving the volts unchanged creating a Solar array of with a value of
120v 16.5 amp 660w . That is the way it is supposed to be wired. But the charge controller says it’s harvesting over 1400w. Once I seen that I knew the wiring was different but the guy I am trying to help is under the impression that by putting the three strings in parallel means adding all nine panels power together. It is very dangerous and I for one don’t want him to get killed. Please if I’m wrong teach me how to understand why I’m wrong because that is how I confused my personal system and I don’t harvest anything higher then the watts times three .my panels have different values but the configuration is supposed to be the same. He is fighting with me demanding that is how it’s wired. If that is so then way is the watts at 1400w instead of 660w.
Joaquin Valdez
Please state your exact panel type or parameters, your location and direction. Than we can help putting it into MPPT calculator and PV GIS.
120V x 5.5A are 660W.
Putting 3 strings in parallel with same direction would give 1,980W “peak”.
The 159/70 is limited to 70A x 24V equals 1,680 W.
If it delivers 1,400W only, the following “issues” can apply:
- shadow , 5% shadow can limit the panel to 30%
- bad connection, check with FLIR camera or remote temperature measurement device
- Loss and voltage drop, due to thin cables or not cleaned surfaces-> use extra voltage sense cable on MP2 and clean surfaces with isopropanol
- Wrong battery parameters not raising voltage high enough
- high resistance in defective batteries
Is this on the panel? Under isc or imp?
These are panels specs not tracking specs.
The mppt can track differently.
You have to be the first person i have ever read to be worried about more than the expected power 
Your strings are identical, you haven’t over amped the inout in ISC your set up is good.
The only convmcerns should be warm connecters and that the connectors and switch gear can handle the power.
3 panels of 220W each in series will give you a string of 660W.
In series, current (A) remains the same and voltages (V) are added up.
Power (P) = A x V
3x 40V x 5.5A = 120V x 5.5A = 660W
In parallel, voltage remains the same but current gets added up.
So with 3 series strings of 660W in parallel, you get 1980Wp.
Electrics 101.
Max 220w
Vmp 40.
Imp 5.5a
Vod 47.8v
Isc 5.9 a
Max series fuse 15 a
600v max system
#1. 3 panels in series = 120v 5.5a 220w
#2. 3 panels in series = 120v 5.5a 220w
#3 3 panels in series = 120v 5.5a 220w.
Now we take the three positive wires parallel them together and then the same way with the neutral creatinga Solar array.of 120v 16.5 a 660w. So I guess my question would be very selfish when I ask. Is this math correct? Did I do that correct? Because if that is wrong please teach me. So I can understand what it is that I’m making a mistake. Because when I see that the array produces 660 W, a power and then the charge controller says it is pulling in 1400 W. It tells that mix my mind want to take apart.The entire array and start over from scratch.But somebody believes with his entire heart that it is put together correctly
Joaquin Valdez
The math is wrong, as I explained in my previous post.
Connecting 3 panels (each 220W, 40V, 5.5A) in series will give you a string of 660W, 120V, 5.5A.
P = U x I
I put your custom panel into Victron’s MPPT calculator.
If you are in the Netherlands or have similar climate, 3p3s has moe than 150V V open-circuite, which might destroy aour MPPT150/70 on could days.
Pls find the configuration below:
Thank you. Thank you for being so on the ball, sir. Thank you, please continue with the lesson. This is exactly what it is I needed. These panels are created by Sunpower company.I’ve got a picture of the Sticker with the values on the back of it
Joaquin Valdez
With those numbers I put 3 panels in series and came up with a 120 V by.
5.5 amps 220 W.
Is that correct?
I’m assuming it is so I made three sets each becoming 120v 5.5a 220w.
With those three I parallel them into a single system with values of 120v 16.5a and 660w. Is that correct? Assuming it is .when I see the controller harvesting 1400w I see redflags.is it posable for the 660w power capable of creating 880 more watts?
Joaquin Valdez
For the THIRD time: if you connect 3x 220W panels together, you get a string of 660W.
Doesn’t matter if you connect them in series or parallel.
3x 220W = 660W
9x 220W = 1980W
If you connect 3 panels in series, Voltage will be 120V.
If you connect 3 panels parallel, Amps will be 16.5A.
In a 3s3p configuration, you’ll get a 120V, 16.5A, 1980W configuration.
If this math is too difficult, I suggest you leave electric works to a more qualified person.
Sorry, but you need to read the answers and repeat basic physics.
Power is measured in W(att)
Current is measured in A(mpere)
Voltage is measured in V(olt)
Power is the product of current multiplied by voltage.
The MPPT 150/70 can charge the battery with 70Ax24V=1,680W at 24V or
70Ax48V=3,360W at 48V.
A 48V-system usually charges at 55,2-57,6V giving peak charge at around 3,800 W.
Panels and strings…
The power adds up in any case.
If you put panels in series (chain of + from p1 to - of p2), the voltages adds up and current stays the same. This is called a string.
If you put panels in parallel (+ together, - together), the current adds up and voltage remains.
The voltage depends on sun intensity (irradiation) and on temperature. The lower the temperature, the higher the voltage.
If you are living I Mexico, you get completely different values compared to Alaska!
Panels degrade over time. You seem to have old panels which might not deliver full 220W.
The angel to sun und local conditions have a major impact. Best would be providing a picture.
We need your location and please use the MPPT calculator linked… I have updated with your panels, but still in the Netherlands.
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