Hi guys.
I was looking at the MPPT configuration on the Deye inverters.

It has 2 MPPT's where MPPT1 has 2 inputs.

I'm currently runing 2 strings in parallel and I connected them in parallel on the roof, so I come down with one set of wires only. Put them on MPPT1 input 1.

This strings are on SOUTH (I live in Europe so bear with the South positioning ) .

Now , I am planing to add one ,  if possible 2 more strings , one on East and one on West.

As the East and West will only receive each partial sun during the day ... what would be my best option ?

Run the existing strings on MPPT2 and then use split MPPT1 for the E and W ?

As far as I can see there is no blocking diode on MPPT1 tracker ....

Options , ideas ?

What panels are you using 

I do believe the two inputs simply parallel on the board side. Is that's correct, then it makes no difference which one you use. 

@Tariq :

Does it matter ? My question is related to panels configuration and how do I add more in 2 more strings without loosing to much power.
I know I will have at least one string that will not produce anything during half the day but I don't want to have 2 strings that pull each-other down.

@Speedster I think it is just parallel connection on the board yes , now I need to figure out how do I reconfigure everything (even if I must split the first parallel string).

Edited October 5, 20223 yr by Jaxone

Hi jaxone, we're you able to figure out the best setup for the 3rd pv string? 

I have similar issue. I have panels on southeast side and 13 on southwest side, each goes into separate mppt input on the deye. However im not sure how to add 3rd string w maybe 10 panels on the northeast side. Im not expecting much from this 3rd string but maybe some ambient power generation could add to the overall output. But im not sure if the northeast 3rd string will bog down the other strings. Any ideas how to do it ideally? 🤔 😁 

Thanks for any input on this. 

JD

3 hours ago, janek said:

Hi jaxone, we're you able to figure out the best setup for the 3rd pv string? 

I have similar issue. I have panels on southeast side and 13 on southwest side, each goes into separate mppt input on the deye. However im not sure how to add 3rd string w maybe 10 panels on the northeast side. Im not expecting much from this 3rd string but maybe some ambient power generation could add to the overall output. But im not sure if the northeast 3rd string will bog down the other strings. Any ideas how to do it ideally? 🤔 😁 

Thanks for any input on this. 

JD

Specs for the panels is a must in order to venture any suggestion. 

@janek As the post above suggests we need to know the specs of panels in each string to be sure the amps and volts will work together correctly.

Disclaimer: This is not an ideal situation as you have three strings with three different orientations and the Deye 12kw only has 2 trackers. Some trial and error maybe required to get the best results.

Recommendation: Assuming you have the same inverter as in the original post (12kw 3phase), this has two trackers but allows three strings to be connected, two of the strings will be connected to the same tracker.

Also assuming you are using the same panels in your two existing strings (southeast and southwest) I would connect these to the same tracker on string 1 & 2. I would then add your new string (northeast) onto string 3 on its own tracker.

Worst case: If the two strings facing south get sun at different enough times it will hurt the output of tracker 1. You mention that the the northeast string may not make alot of power. You may end up with less power from 3 strings crammed into two trackers, then if you had just stayed with your original two strings each with their own tracker.

Hi Ham, thnx for the reply.

my panels are Longi - Lr5-66hph-510m
VOC - 45.85
Vmp - 38.68
Imp - 13.19A
Isc - 14.05A
Pmax - 510w

i thought that if i connect the 3rd string to the MPPT1 together with the 1st string, then the power generated would just add up, same as if the panels were 9S2P connected on the roof somewhere.

And eventhough it would be different orientation, then it should hurt as much if one string is producing less, it would just add less generated power to the MPPT1 input. Or is my understanding wrong?
Also, would it be possible to have different number of panels for each string going into the MPPT1 inputs? same panels specs but different qty. i can fit more than 9 panels on the Northeast side . Would that be a problem?
Guys at Deye told me they must be same specs panels and same qty for each string going into the MPPT1 connectors.  I would think the two separate inputs on the MPPT1 are just like some sort of a combiner box. or am i wrong again?
 

would use of a diode solve anything ? the Deye guys suggested to have a diode on each of the two strings going into MPPT1.
thanks for your help guys.