Enphase Energy sixth-generation microinverters (IQ7, IQ7+, IQ 7X, IQ 6, and IQ 6+), fifth-generation microinverters (S230, S280), and fourth-generation microinverters (C250, M250 and the M215) all have DC isolated, integrated ground (IG). Enphase Microinverters with Integrated Ground detect ground faults on either the DC positive or negative conductor of the PV module. These microinverters always check the insulation resistance before exporting power.
Older Enphase Microinverter models do not include IG technology and require equipment grounding.
TIP: If installing a mix of IG (Integrated Ground) and non-IG microinverters, install the non-IG microinverters closer (electrically) to the junction box to minimize GEC use.