... Stainless steel shell with hermetic seal9. Multi selection:Low frequency transformar isolation type,transformer less type,transformer less type ... the grid tracking,power factor close to 1, Current low harmonic content, non-polluting power grid, no impact13 ... power10 KVA25 KVA50 KVA100 KVA250 KVA500 KVAinsulate modeLow frequency transformerRecommended PV array power12 KWp36 KWp60 KWp120KWp300 KWp600 ...