Installation

How do I know if my PV system needs fuses?   

The commonly accepted interpretation of the NEC on this topic is that if an inverter that does not allow AC current backfeed (like the FRONIUS IG), the equation to be used is (N-1) x 1.25 x Isc < module series fuse rating, where N equals the number of strings, Isc is the STC short circuit current of the module in use, and the series fuse rating is the value found on the manufacturer’s module specification sheet.  If the number is less than the series fuse rating, fuses are not required, and if it is larger fuses are required. 
 

Can my FRONIUS IG be installed outdoors? 

Yes it can!  The FRONIUS IG is housed in a NEMA 3R box, which is an outdoor rating.    All of our printed circuit boards (PCB’s) are conformal coated to protect the electronic components from moisture and dust.  This is just another detail that we have added to the FRONIUS IG to ensure reliability. 
 
 
 Do I need to install a DC disconnect with my FRONIUS IG? 

The FRONIUS IG is equipped to meet the standard NEC DC-disconnect requirements so that you can save time and money.  Certain jurisdictions or site-specific conditions may require the addition of an external DC disconnect, so inquire with your local inspector if in doubt.  Although most inverters with integrated disconnects are approved as meeting all codes and standards, the final word on compliance is up to the local authority having jurisdiction (AHJ).  
 
 
Do I need to install an AC disconnect with my FRONIUS IG? 

The AC disconnect is a utility-defined requirement.  The FRONIUS IG is equipped with an internal AC disconnect, but many utilities may require an additional external, lockable, and/or visible-break AC disconnect.  Contact your local utility for their AC disconnect requirements to see if the FRONIUS IG’s AC disconnect will meet the local requirements.