Why does outback say "don't mix 150V and 300V charge controllers"

richardimorse

I see outback advise against mixing Flexmax 80 (150V 80A) and Flexmax Extrene (300V 100A) in the same installation,
I can not see why that is - when no bus bars are used and each controller has its own array

Any ideas ?

jonr

Probably same issues discussed here:

http://www.outbackpower.com/downloads/documents/appnotes/fm100_fm80_app_note.pdf

richardimorse

Not sure what the rationale is, will have to read up about FM100 stacking and their internal GFDI fuses on the FM100.  FM80's just connect to the same output bus with a common trip device so isn't this the same as using 1 * 2pole GFDI vs 2 * 1 pole GFDI breakers for 2 * FM80

Still don't understand fully why I shouldn't just add a FM100 to my FM80 and let them work independently adding their amps to the battery power bus