How to wire up a Mixed Bag of Panels to a FM80 MPPT

nigtomdaw

Hi been away a while but been very busy, what credit crunch ? Still been reading ocasionally though not posting.

I have a customer who sourced two single axis Lorentz Trackers from me and has now informed me of the make up of his panels which are as follows.

One of the trackers has 12 panels of the following specification

VOC 48.3
Vmp 39.8
IMP 5.4
ISC 5.8

The second is a mixed bag

Six have to above mentioned specification

Four has the following

VOC 45
VMP 45
IMP 5.1
ISC 4.5.

The last two

VOC 32.8
VMp 28.9
IMP 7.44
ISC 8.21

He lives in Southern France and the questions are as follows - Tracker No1 with all the same panels 6 strings of two or 4 strings of three to a Flexmax 80.

The second set as described is a real mixed bag any thoughts and suggestions. Again going to a FM80- Nominal Battery voltage will be 48v

Regards Nigel

BB.

Re: How to wire up a Mixed Bag of Panels to a FM80 MPPT

Glad to hear you are doing well Nigel!

nigtomdaw wrote: »

One of the trackers has 12 panels of the following specification

VOC 48.3
Vmp 39.8
IMP 5.4
ISC 5.8

The second is a mixed bag

Six have to above mentioned specification

Four has the following

VOC 45
VMP 45 (assuming this number is wrong)
IMP 5.1
ISC 4.5.

I treat the above panels as being roughly the same Vmp (less than 10% difference)... Put 2 panels in series x 5 parallel strings (keep same model in each series string). This is assuming the second Vmp is a typo and is really around 36-37 volts or so...

The last two

VOC 32.8
VMp 28.9
IMP 7.44
ISC 8.21

I would purchase 1 more panel and put 3 in series and purchase either a second smaller MPPT charge controller or even a PWM controller (if money is an issue).

He lives in Southern France and the questions are as follows - Tracker No1 with all the same panels 6 strings of two or 4 strings of three to a Flexmax 80.

The second set as described is a real mixed bag any thoughts and suggestions. Again going to a FM80- Nominal Battery voltage will be 48v

I think that 4 panels in series is way to high of Array Voc (>>150 VDC limit of controller). Even 3 panels in series is probably too hot (for Voc 45/48 panels).

-Bill

nigtomdaw

Re: How to wire up a Mixed Bag of Panels to a FM80 MPPT

Thanks Bill Yes I think its a typo also I just cut and pasted from his email.

So if Ive got it right

Tracker No 1 is 6 strings of two panels in series.
Tracker No 2 is 5 Strings of two panels in series

Leaving the two odd units to be wire to a 3rd smaller CC or even directed to powering the tracker arrays themselves.

Regards Nigel