Neutral Wire Size for Sunny Boy TL inverter

[innavent]

I'm looking at a Sunny Boy TL inverter and am trying to figure out how to size the neutral wire. An old SMA neutral wire size technical reference suggests using 250.122 (neutral same size as ground), but is this accurate even with a transformer-less inverter? Where would I go to size the neutral wires for non microinverters?

Thanks!
Kevin

 

[jaggedben]

It makes no difference if an inverter is a transformerless model or not.

705.95B(B) says a neutral can be sized the same as the EGC if it is used 'soley for instrumentation, voltage detection, or phase dectection'. Your AHJ may want to see a neutral sized the same as the circuit conductors unless you can show documentation from the manufacturer that the neutral is only for used for these things.

On all jobs I have ever done we have simply sized the neutral the same as the phase conductors.

 

[innavent]

That makes sense. I've always done the same, but I just saw a planset where the neutral wire was two sizes smaller than the current carrying conductors...

Thanks for the reference!