Travis,
You are exactly right. As long as you do not exceed the max open
circuit voltage or short circuit current rating you're perfectly fine.
Even if you put 300W of module on the inverter, it will just hit power
limit until the irradiance declines enough to let the MPPT work again.
No problem. No damage to the module or the inverter. The "smoke
threshold" voltage is many volts above our stated maximum input voltage.
Of course, it probably doesn't make economic sense to waste that much
glass.
In your case, two Kyoceras in series will work just fine. Depending on
the age of the modules, soiling, etc., you'll probably have less than
240W peak. I'd guess you will seldom see the inverters hit power limit.
This configuration will have no impact on MTBF or reliability.
Do be aware that if you shade one of the two modules, you'll limit the
output of both modules in the series string. No worse than a standard
string inverter.
We chose a Tyco CPC connector for cost, reliability, and environmental
reasons. If you can find a connector that meets the demanding NEMA6
requirements at a better price, please let me know. We're constantly
looking for ways to reduce product cost without degrading reliability.
Hope this helps.
See Ya!
Marv
Enphase Energy
707 763-4784 x7016
Travis Creswell wrote:
Greetings Wrenches,
I have customer with a three module array made up of 120 watt Kyocera's that
charge the battery bank underutilized of “hobby system”.
It spends most time in float plus were adding a 5.5 kW direct grid tied
array that require us to move the existing array so the customer is
interested in putting an EnPhase inverter on two of the Kyocera 120’s.
I’ve looked over the EnPhase specs and don’t see a reason why I can’t wire
two KC120’s in series and feed the EnPhase with them. I do see them listing
it’s compatibility of up 225 watt modules but am having a hard time getting
much further. I didn’t find a max input wattage so what happens if I put
240 watts to the EnPhase? Does the magic smoke come out on day one or does
MTBF drop from 32,895 years to 80 years?
Even is the EnPhase's max output is 200 watts it's still more kWh/day then
the hobby system that spending most of it's time in float. I can see no
difference between one 72 cell module and two 36 cell module in series.
Also it looks like there is unique connector coming off the AC side of the
module. How do I deal with that?
Best and thanks in advance!
Travis Creswell
Ozark Energy Services
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