Classic Label Question

[Kent0]

The Classic 150 shows the max PV Voc = 150 plus the battery voltage.  It also says max PV Voltage (operating) = 150.  Since that is what it says on the label, it is a code violation to install it in a manner that does not comply.  And there are a couple scenarios where staying within these limits seems problematic: 1) Consider a Sanyo HIT 220 (at 25°C, Voc = 52.3, Vmp = 42.7, and the temperature coefficient is -0.145 V/°C) in a location like Eastern Oregon where -30°F (-35°C) is typically the design temperature.  At -35°C Voc = 60.8 and Vmp = 51.3.  For battery voltages greater than 36 volts, it looks like three modules in series is suitable (3*60.8 < 150 + 36).  In fact, the Classic panel simulation accepts three in series as suitable.  However, with three modules in series the operating voltage could be as high as 154 volts which is beyond the listed maximum.  2) When the batteries reach the absorption setting, the operating voltage will increase above Vmp as less power is required.  So even when it isn't -35°C, the maximum operating voltage could be exceeded.  I think I'm confused.  What does "max PV Voltage (operating) 150" mean?

[Robin]

I tried the simulation. This is a new version and it obviously has an error in the math. Your modules resulted in 192 volts. Give a 48 volt battery bank, that would not hurt the Classic, but it would also never turn on due to such a high voltage. The simulation is suppose to warn you when the VOC goes above 150V. The warning says that turn on may be delayed. This configuration would probably never turn on in cold temperatures. The Classic 150 simply shuts off above 150V. We have designed in a margin above the operating voltage that allows for brief excursions above the operating voltage. All other controllers warn of voiding the warranty and very well may blow up when operating voltage is exceeded. The VOC of 192 volts is so high, it shows an improper design. We will look into why ther was no warning. The warning gets more drastic when operating voltage plus battery voltage is exceeded. Be careful not to abuse the HyperVOC zone. IT can nail you in cold weather. The Classic 150 is indeed a 150V unit. It just doesn't blow up when exceeding the operating voltage.
I hope this helps.

[Kent0]

Thanks, Robin.  I think I understand the Hyper Voc spec now.  Hyper Voc means higher than normal voltages due to cold weather won't damage the Classic.  But the Classic won't operate until Voc is within normal operating range, 150 volts for the Classic 150.