Rapid shutdown Port

billybob9

Like a car port this rapid shutdown port is made to shade the device. Using a 28' ( Two 14' Iron ridge )  rack and Canadian solar panels 300W ( 2 strings of 8 panels ) I was left with enough room to add the SMA rapid shut down, on the end.  I replaced the screws on the RS box with hand tightening screws ( 4 ) to mount the Shade Port. So now it's just a waiting game to see if Over heating is causing the SMA rapid shutdown box to fail..  

billybob9

Wow, just fired up the SMA 5.0 inverter that has 65' of #10 wire ( counting home run ) to 300W CS panels. No Optimizers so 37Vdc X 8=296Vdc. Inverter reads, string A 285Vdc and string B 284Vdc. 600Vdc is Max for the Inverter. You will have a pulsing green lite on the inverter if your in the 90% voltage range. From 9 to 5 yesterday it was pulsing, so this guy really Cranks. I might have to go to a 6.0 inverter if I get an error or it just blows up.

BB.

You also need to look at the current from the array === Power = Voltage * Current. Voltage by itself is not the full story.

-Bill

icarus

The SMA should handle a routine over capacity by simply clipping as needed.  AFIK, good grid tie design tries to install an inverter so that it runs at it’s most efficient “sweet spot” for as much of the time as possible.  It is generally better to under inverter and over module the PV than the reverse, within limits of course, maybe 10%?   For example, my 6 kw SMA inverter almost never (actually never because of aspect issues) see 6 kw of PV from a 6.2 kw array.  5.8 on a really good day, haven’t watched it closely on an edge of cloud event however.

Tony

PS.  Get the SMA “Sunny Portal” or go into the inverters wifi and get a real time look at string power, volts/amps/watts etc.  You can watch it in real time from the inverter, time delayed from the Portal.  

billybob9

Thanks Bill, I'll do that since I'm pretty much maxed out. The array is attached to the Rapid shutdown box with 2 sets of inputs per string in parallel. So one set must be plugged but easy to remove and use for test purposes. I used a 30A 2 pole breaker as per SMA instruction but will look in manual for more INFO.

billybob9

Thanks Tony

  I don't think I will see 5.0KW either but was not sure what would happen if I did. I'm facing south into a bright California summer sun so was a little worried. I'll be doing the wifi next or maybe directly into a computer. My Rapid shut down works as advertised but the green lite doesn't come on. I really don't need it as the Inverter has the green lite in all safety operations.