String sizing?

[vonbek]

Hello everyone,
I have what is probably a simple question, but I can't figure it out. I need to know how many kyocera KD140 modules I can put on a
Trace/Xantrex/Schneider C40 charge controller with a 48 volt battery bank. Schneider told me I can put one string of three modules on it, and that seems wrong. My brother says I can put 3 strings of 4 on it . That is a big difference, are either of these guys correct?
The open circuit voltage of the modules is 22.1v and the short circuit current is 8.68 amps. I live in Northeast Washington State where it can get quite cold in the winter. I think Robin and his Brother invented this unit when they were at Trace, is that correct?
Anyway if someone could tell me how to figure this correctly I would appreciate it.
Thanks,
Dan

[dgd]

48v pwm controller needs string of 4 by (nominal) 12v panels
Each string makes maximum amps about 8 so five strings will work to a 40amp controller
But you should do the job properly and use an MPPT controller so as to not waste power from the PV array. With a pwm controller such as the C40 you will probably get a maximum of about 105 to 110 watts of power from each 140 watt panel, more likely 80 to 100 watts. With a decent mppt controller (such as the Midnite KID or Classic) this would be closer to the 140watt nameplate rating on a good bright day.

dgd

[vonbek]

Thanks,
so if I understand the process correctly, for example, in this same scenario if the battery bank was 24 volts I could use 5 strings of 2 panels and if a 12 volt bank I would use 5 stings of 1 panel. Is that correct? As for using an mppt controller, economics are probably forcing me to use the C40 for now. So what the flarn is the Schneider tech support guy doing telling me I can only put 1 string of 3 on the controller?
Appreciated.
Dan

[dgd]

You got it right 
The tech probably misunderstood what you were asking, that happens

dgd

[vonbek]

Thanks for the help. Much appreciated.
Dan