Is OutBack trying to be misleading?
When sizing the electrical for a PV source circuit for example; wire size, disconnects, fuses, and this includes, but is not limited to, the charge controller, the NEC (National Electrical Code) dictates a correction factor of 125% of the short circuit rating of a PV module at STC(Standard Test Conditions.) Before this the UL (Underwriters Laboratories) dictates 125% of that same rating. Typically a correction factor of 156% is used to cover both of these. 125% X 125% = 156%.
An example: A PV module has an Soc. rating of 7.56 amps and you have ten such PV modules wired in parallel/series for a total of 37.8 amp Soc, at 24 volts nominal. Multiply that 37.8 X 156% = 59 amps.
There is another NEC correction factor for ambient low temperature but I am not going into that one at this time.
OutBacks claim is a Maximum output of direct current of 80 amps continuous. They do not give a maximum input from the PV source circuit with the 156% correction factor. They do how ever give some figures to that regard but in a very strange way.
1000 watts at 12 volts nominal?
I mean all I have to is divide 1000 watts by a particular PV modules Vpm or what I like to call its "working voltage" and that should give me the maximum number of PV modules I can put on a FlexMax 80 once I do a little more math.
Example: Here are the ratings of a Kyocera KC130TM;
17.6 volts at max. power
8.02 short circuit amps.
1000 / 17.6 = 56.81
56.81 / 8.02 = 7
So 7 - KC130TM's would be the maximum number one could place on the FlexMax assuming a 12 volt nominal battery bank.
I am sure there is a good reason for doing it this way but it sure does seem kinda like being made to "jump through hoops" if you know what I mean.
I suppose I could just divide the 1000 watts by the rated wattage if the PV module I might be using and get the same answer.
1000 / 130 = 7
Can anybody clarify this?
Is this math right?
