SMA America. The maker has introduced specially configured Sunny Boy 4000US solar inverters for use on homes with 100-amp electrical service. Designed to provide installers with greater flexibility on residential retrofit projects, the inverter’s electric current output has been reduced to 16 amps to comply with National Electric Code standards, while offering installers additional sizing options. Older homes with 100-amp electrical service can now have solar arrays installed more easily without having to upgrade the electrical. 916.625.0870.